JP3887557B2 - Ground improvement method and its monitoring mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ground improvement method for creating an underground pile to be a foundation structure, such as a water blocking wall, a continuous underground wall, or a foundation ground, and a monitoring mechanism applied thereto.
[0002]
[Prior art]
As this kind of ground improvement method, one disclosed in, for example, Japanese Patent Laid-Open No. 7-252823 has been known. FIG. 6 is a schematic diagram of the ground improvement method.
In this ground improvement method, a swivel 3 is provided at the upper part of the hardener injection pipe 2, a monitor mechanism 4 having upper and lower multistage cutting blades 6 is provided at the lower part of the hardener injection pipe 2, and the hardener injection is performed by the boring device 1. The pipe 2 is swung to form a perforation 12 to a target depth in the ground, and then the jet G of the hardened material g is ejected from the tip of the cutting blade 6, and the hardened material injection pipe 2 is pulled up while being swung. By cutting the ground around the cutting blade 6 with the jet G, the upper and lower jets G and G intersect and collide to limit the cutting range, and the uncured pile P in the cutting area 13 is cured. Thus, the foundation structure 14 is created in the ground.
[0003]
According to this ground improvement method, the upper and lower jets G and G intersect and collide with each other to limit the cutting range. Therefore, by reducing the discharge amount of the jet G and increasing the discharge pressure, the target range is shortened. Although there is an advantage that it can be cut in time and the consumption of the hardener g and the amount of mud are greatly reduced, there is room for improvement in the following points.
[0004]
In the above prior art, the upper and lower jets G and G intersect and collide to limit the cutting range, so that a truncated cone-shaped uncut portion is formed at the lower or upper portion of the cutting area 13 as shown in FIG. For example, when excavating the lower side of an existing floor structure, the upper jet G of the upper and lower jets G and G is blocked by the floor structure, so that the upper part of the cutting area 13 unnecessarily expands. It will be.
[0005]
The present invention has been made in view of such circumstances, and its purpose is to provide a ground improvement method that does not cause uncut portions in the lower and upper portions of the cutting area, and prevents the upper portion of the cutting area from unnecessarily expanding. It is to provide an applicable monitoring mechanism.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is configured as follows .
[0007]
[0008]
The invention described in claim 1 is a monitor having a plurality of cutting blades 6 and a plurality of injection pipes 8 provided separately from the cutting blades 6 and ejecting a jet G of cutting fluid at the lower portion of the hardener injection pipe 2. A mechanism 4 is provided, and the hardener injection pipe 2 is swung by the boring device 1 to form a perforation 12 to a target depth in the ground, and then a cutting fluid jet G is jetted from the tip of the jet pipe 8 to harden the hardener. By pulling up the material injection pipe 2 while swiveling, the ground around the cutting blade 6 is cut by the jet G, and the cutting range is limited by crossing and colliding two or more jets G and G. This is a ground improvement method for creating a foundation structure 14 in the ground by hardening the uncured pile P in the cutting area 13, and the plurality of injection pipes 8 are substantially arranged within the rotation radius R of the cutting blade 6. Provided within the same horizontal plane, The cutting blades 6 provided on Kutomo lower side, two or more jets G-G crossed-collision in substantially the same horizontal plane, characterized in that so as to limit its cutting range.
[0009]
The invention described in claim 2 comprises a plurality of cutting blades 6 and a plurality of injection pipes 8 provided separately from the cutting blades (6) and ejecting a jet G of cutting fluid from the tip. A monitoring mechanism configured to cross and collide G and G to limit the cutting range, and the plurality of injection pipes 8 are provided in a substantially same horizontal plane within the rotation radius R of the cutting blade 6; The cutting blade 6 is provided at least on the lower side of the injection pipe 8, and two or more jets G and G intersect and collide in substantially the same horizontal plane to limit the cutting range .
[0010]
Invention as set forth in claim 3, in the monitor system according to claim 2, the provided reaction force receiving member 10 at the top of the monitor main body 5, perforations of claim 1 by the reaction force receiving member 10 12 It is configured to receive the jet reaction force of the jets G and G.
[0011]
[Operation and effect of the invention]
In the invention of claim 1 or 2, provided with an injection pipe 8 of multiple substantially the same horizontal plane, two or more jets G-G by intersecting-collision in substantially the same horizontal plane because it limits the cutting range As in the conventional example, there is no frustoconical uncut portion at the lower and upper portions of the cutting area 13, and even when the lower ground of the existing floor structure is cut by the jet, the upper portion of the cutting area 13 Will not spread unnecessarily.
[0012]
According to the fifth aspect of the present invention, the reaction force receiving member 10 is provided on the upper portion of the monitor mechanism, and the reaction force receiving member 10 is configured to receive the jet reaction force of the jets G and G within the perforations 12. When the hardened material injection pipe 2 is pulled up while being driven to swivel while jetting the cutting fluid jet G to one side, there is no possibility that the swirling center will be shifted by the cutting fluid jet G. Thereby, a uniform circular cutting area in a plan view, and thus a uniform circular foundation structure can be created.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a monitor mechanism according to a reference example 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.
[0014]
As shown in FIGS. 1A and 1B, the monitor mechanism 4 includes a monitor main body 5 connected to a lower portion of the hardener injection pipe 2 and upper sides protruding from the monitor main body 5 in the rotational radius direction. Cutting blades 6a and lower cutting blades 6b, and a lower cutting bit 10 provided at the lower part of the monitor main body 5, and a jet G of a hardened material g is ejected as a cutting fluid from the tip of the upper cutting blade 6a. In addition, the jets G are configured to intersect and collide in substantially the same horizontal plane.
[0015]
The hardener injection pipe 2 is composed of a double tube rod, and the hardener injection pipe 2 and the monitor body 5 are provided with a hardener jet passage (not shown) formed along the axial center thereof, and outside the jet passage. And an air jet passage (not shown) formed in an annular shape. Further, an injection nozzle 7 for ejecting a hardener and air is provided at the tip of the upper cutting blade 6a, and two jets G and G ejected from adjacent cutting blades 6a intersect and collide in substantially the same horizontal plane. By doing so, it is configured to limit the cutting range of the ground.
[0016]
Each of the cutting blades 6a and 6b is provided with a plurality of excavation bits 9 on the lower surface thereof, and is used for turning the cutting blades 6a and 6b to form the drill holes 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, and the jet G of the hardening material g is guided by the surrounding injection air A so as to increase the flight distance. It is configured.
[0017]
FIG. 1 (C) shows a modified example of the monitoring mechanism. In this modified example, three cutting blades 6a are provided in substantially the same horizontal plane, and a jet G of a hardened material is ejected from the tip of each cutting blade 6a. In addition, the three jets G are configured to intersect and collide in substantially the same horizontal plane.
[0018]
2 (a) to 2 (d) are schematic views showing the procedure of the ground improvement method according to the reference example , FIG. 2 (a) is a drilling step by a cutting blade, and FIG. 2 (b) is a jet of bentonite mud water w. An injection test by W, FIG. 2C shows a creation process, and FIG. 2D shows a hole filling process. Hereinafter, this ground improvement construction method will be described with reference to FIGS.
[0019]
a. Drilling process << Fig. 2 (a) >>
In the drilling process, the boring apparatus 1 is installed on the ground, bentonite mud water w and air a are injected from the swivel 3 connected to the upper end of the hardener injection pipe 2, and the hardener injection pipe 2 is swiveled by the boring apparatus 1. The bentonite mud water w and air a are ejected from the lower part 10 of the monitor mechanism 4 connected to the lower part of the hardener injection pipe 2, and the above-mentioned cutting blades 6a and 6b are swung to form a perforation 12 having a predetermined depth. Form. At this time, the bentonite mud water W is circulated.
[0020]
b. Injection test << Fig. 2 (b) >>
In the injection test, a steel ball is introduced into the hardened material injection pipe 2 to close the muddy water discharge hole in the lower part 10 of the monitor mechanism 4, and the hardened material injection pipe 2 is swung from the tip of the cutting blade 6 a. A muddy water and air jet W as a cutting fluid is continuously ejected to cut the surrounding ground. At this time, the muddy water jets W ejected from the tips of the cutting blades 6a are caused to intersect and collide 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 process proceeds to the creation process.
[0021]
c. Creation process << Fig. 2 (c) >>
In the formation process, the boring device 1 is operated and pulled up while the hardener injection pipe 2 is swiveled to drive the hardener g and the high pressure air a continuously ejected at a high pressure from the tip of the upper cutting blade 6a. The ground in the outer peripheral area is cut by the jet G, and an uncured pile P is formed in the cutting area 13. At this time, the cutting range of the ground is limited by a plurality of jets G intersecting and colliding. Incidentally, the discharge pressure of the hardener is 10 to 100 MPa, the discharge amount from one nozzle Le is 40~300l / min, the discharge pressure of the compressed air 0.6～3MPa, discharge amount 1.0～10.0M ³ Set to / min.
[0022]
At this time, the jet G of the hardened material g is less attenuated by the length of the cutting blade 6a, and is guided by the jet air A to fly farther and cut the ground greatly, and the cutting blades 6a and 6b. The hardened material g and the cutting mud are kneaded by turning the jet G. As a result, a large uncured pile P can be created, and the creation time of the foundation structure 13 can be further shortened.
[0023]
The surplus waste mud 15 is pushed up by the ejected curing material and air, and is discharged to the ground through the perforations 12. The mud 15 is removed by the mud pump 16. When the creation of the target range is completed, the supply of the curing material g and air a is stopped.
[0024]
d. Cavity filling process << Fig. 2 (d) >>
In the hole filling process, the hardener injection pipe 2 is pulled out to the ground, and the inside of the pipe is washed with fresh water. Thereafter, if necessary, the hole 12 is filled. And it moves to the next creation point and uncured pile P is created in the soil in the same procedure. When the uncured pile P is cured, the foundation structure 14 is formed in the ground.
[0025]
FIG. 3 is a view corresponding to FIG. 1 of the monitor mechanism according to the first embodiment of the present invention.
The monitoring mechanism 4 is positioned between the upper and lower cutting blades 6a and 6b and the cutting blades 6a and 6b, and is within the rotation radius R of the cutting blades 6a and 6b, and is substantially in the same horizontal plane. The four injection pipes 8 are provided, and two adjacent jets G and G are made to intersect and collide in substantially the same horizontal plane to limit the cutting range.
[0026]
In this embodiment, the injection pipe 8 is positioned in the middle of the cutting blades 6a and 6b so that no unnecessary cutting load is applied to the injection pipe 8 in the drilling step << FIG. 2 (a) >>. is there. Therefore, if the cutting blade 6 is provided at least on the lower side of the injection pipe 8, the above intention is achieved. Other points are configured in the same manner as the reference example .
[0027]
FIG. 4A is a plan view of a monitor mechanism according to the second embodiment of the present invention, and FIG. 4B is a schematic view of a creation process by the monitor mechanism.
In this embodiment, in the reference example or the first embodiment, a reaction force receiving member 10 is provided on the upper part of the monitor body 5, and the reaction force receiving member 10 causes the jet G / G to be injected in the perforation 12. It is configured to receive power. The other points are configured in the same manner as the reference example or the first embodiment.
[0028]
The above configuration is intended to prevent the swirling center from being shifted to the opposite side by the jet G when the hardening material injection pipe 2 is pulled up while being swung while the jet G of the curing material is ejected to one side. Is. Thereby, the uniform circular cutting area 13 can be created in plan view. In this embodiment, the left and right reaction force receiving members 10 and 10 are exemplified, but this is in consideration of the rotational balance of the monitor mechanism 4, and at least the jet reaction of the jets G and G is taken into account. One thing that takes power is enough.
[0029]
FIG. 5A is a plan view of a monitor mechanism according to the third embodiment of the present invention, and FIG. 4B is a schematic view of a creation process by the monitor mechanism.
In this embodiment, in the above reference example or the first embodiment, the hardening material injection pipe 2 is constituted by a triple pipe rod, and by using high-pressure water (including high-pressure mud water w) as a cutting fluid, The ground is cut, and a jet G of a hardened material g is jetted from a jet nozzle opened at the lower part of the monitor main body 5 and kneaded with the cutting mud to form an uncured pile P.
[0030]
According to the ground improvement method according to the present invention, the two existing jets G are crossed in substantially the same horizontal plane, thereby eliminating the truncated cone-shaped uncut portions that can be formed at the lower and upper portions of the cutting area. Even when the lower ground of an object is cut with a cross jet, it is possible to eliminate the unnecessary expansion of the upper part of the cutting area.
[0031]
In addition, this invention can be implemented by adding a change suitably as follows, for example. In the above embodiment, the example in which the periphery of the jet G of cutting fluid is guided by the jet air A is exemplified. Thus, the guide by the blast air A may be omitted.
[Brief description of the drawings]
[1] shows a monitoring mechanism according to a reference example of the present invention, FIG. 1 (A) is an elevational view of the monitor mechanism, and FIG. 1 (B) is a plan view of the monitor mechanism, FIG. 1 (C) is its It is a top view which shows the modification of a monitor mechanism.
FIGS. 2A to 2D are schematic views showing a procedure of a ground improvement method according to a reference example .
FIG. 3 is a view corresponding to FIG. 1 of the monitor mechanism according to the first embodiment of the present invention.
FIG. 4A is a plan view of a monitor mechanism according to a second embodiment of the present invention, and FIG. 4B is a schematic view of a creation process by the monitor mechanism.
FIG. 5 (A) is a plan view of a monitor mechanism according to a third embodiment of the present invention, and FIG. 5 (B) is a schematic view of a creation 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 ... Hardener injection tube, 4 ... Monitor mechanism, 5 ... Monitor body, 6 · 6a · 6b ... Cutting blade, 7 ... Injection nozzle, 8 ... Injection tube, 13 ... Cutting zone, 14 ... Substructure, G ... Cutting Liquid jet, g ... cutting fluid (cured material), w ... cutting fluid (muddy water), P ... uncured pile.

Claims (3)

A plurality of cutting blades (6) and a plurality of injection tubes (8) for separately ejecting cutting fluid jets (G) are provided below the hardened material injection tube (2). A monitoring mechanism (4) is provided, and the hardener injection pipe (2) is turned by the boring device (1) to form a perforation (12) to a target depth in the ground, and then from the tip of the injection pipe (8) A jet of cutting fluid (G) is ejected and the hardened material injection pipe (2) is pulled up while being swiveled to cut the ground around the cutting blade (6) with the jet (G). The above jets (G and G) are crossed and collided to limit the cutting range, and the uncured pile (P) in the cutting area (13) is hardened, so that the foundation structure (14) is submerged in the ground. A ground improvement method to be created,
The plurality of injection pipes (8) are provided in substantially the same horizontal plane within the radius of rotation (R) of the cutting blade (6), and the cutting blade (6) is provided at least below the injection pipe (8). A ground improvement construction method characterized in that two or more jets (G and G) intersect and collide in substantially the same horizontal plane to limit the cutting range . A plurality of cutting blades (6) and a plurality of injection pipes (8) that are provided separately from the cutting blades (6) and jet a cutting fluid jet (G) from the tip are provided. G) is a monitoring mechanism configured to cross and collide to limit the cutting range,
The plurality of injection pipes (8) are provided in substantially the same horizontal plane within the radius of rotation (R) of the cutting blade (6), and the cutting blade (6) is provided at least below the injection pipe (8). A monitoring mechanism characterized in that two or more jets (G, G) are configured to intersect and collide in substantially the same horizontal plane to limit the cutting range . The monitoring mechanism according to claim 2 ,
The reaction force receiving member (10) provided in the upper portion of the monitor body (5), the injection of this reactive force catch perforation of claim 1 by members (10) (12) above the jet (G · G) A monitor mechanism characterized by receiving reaction force.

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