JP2019056254A - Ground mixing processing apparatus and mixing processing method using the same - Google Patents

Abstract

[PROBLEMS] To improve agitation efficiency by moving the original soil, that is, earth and sand, up and down, left and right with a helical ribbon blade, and stabilizing the properties of the earth and sand by mixing different soil layers when the soil layer changes in the vertical direction. It can be so.
An agitator having a rotatable rotating shaft 1, an excavating means 2 provided on a lower end side of the rotating shaft, and an agitating blade provided on the upper side of the excavating means and projecting substantially at right angles to the rotating shaft. And a supply pipe 6a, 6b provided along the rotating shaft 1 and capable of injecting the improved material together with the compressed air from the discharge means 5 by means of the discharge shaft 5 provided on the stirring blade. In the mixing processing apparatus, the stirring means is provided on the upper side of the stirring blade 3C and has a spiral or helical shape in which the projecting dimension in the radial direction of the rotary shaft 1 is maximum at the lower end side and gradually decreases toward the upper side. And having a helical ribbon blade 4 having an opening 14 penetrating vertically.
[Selection] Figure 4

Description

  TECHNICAL FIELD The present invention relates to a ground mixing treatment apparatus for jetting an improved material into soft ground and mixing it with in-situ soil, and a mixing treatment method using the same.

  The ground mixing processing apparatus is provided at the rotating shaft 11 (1 in Reference 2) rotated by the driving device and the lower end of the rotating shaft as in Patent Document 1 shown in FIG. 8 and Patent Document 2 shown in FIG. Agitating means having excavating means 19 (8 in Reference 2) and stirring blades 15 and 17 (3A and 3B in Reference 2) provided on the upper side of the excavating means and projecting substantially perpendicular to the rotation axis; Discharge means 16e and 18e provided on the blades (in Reference 2, the mixed ejector 13 in FIG. 9B and the nozzle 20 in FIG. 9C) are piped along the rotating shaft and compressed air is supplied from the discharge means to the compressed material. And supply pipes 16a and 18a (2A and 2B in Reference 2) that enable injection.

  In the mixed processing method using this equipment, solidification type improving materials such as quick lime and cement milk are mixed with in-situ soil in the ground, and the chemical bonding action between the improving material and in-situ soil such as clayey soil is used. The strength of the ground is improved by creating a strong columnar pile or stabilizing the soil properties. In the processing operation, the improvement material sprayed from the discharge means and the in-situ soil were stirred by the stirring means in the intrusion and / or withdrawal process into the soft ground while rotating the rotating shaft, and included in the improvement material. Accompanied by the rise of compressed air along the axis of rotation.

  That is, the discharge means is provided at the root portion or the tip side of the stirring blade, and the improving material is injected together with the compressed air into the gap formed by the rotation of the stirring blade. The improved improvement material sprayed is sprinkled on the rotation trajectory with the rotation of the stirring blade, and is mixed and stirred with the in-situ soil. The compressed air is raised along the rotating shaft 11 toward the ground surface. In this case, in Document 1, the air extending around the rotating shaft 1 and extending in the vertical direction as shown in FIG. 9 is shown in FIG. 9 through the air vent 37 provided on the base end side of the stirring blade as shown in FIG. The recovery rib material 9 is raised through a gap formed between the rotating shaft and the original soil, and discharged to the ground surface.

Japanese Patent No. 4187077 Japanese Patent No. 3416774

  In the above ground mixing treatment device and method, the degree of mixing of the improved material and the in-situ soil almost determines the quality of the ground improvement. Therefore, in order to ensure the quality, the improved material may be mixed uniformly with the in-situ soil. It becomes important. From such a point, conventionally, while dealing with the processing control surface such as the setting of the rotation speed of the rotating shaft and the mixing time, the stirring blade is provided by various co-rotation preventing means (4 in Reference 2) provided with the stirring blade. This is also addressed from the standpoint of the mixing mechanism, which prevents the soil from co-rotating with the movement of the slab, and removes the stirrer blades and soil adhering between the stirrer blades. In other words, the injected improved material and the in-situ soil are mixed and agitated by the rotation of the agitating blades with a movement in the rotational direction exclusively in the horizontal region. As a configuration for increasing the degree of mixing, there is a method called so-called dual-way mixing (two-way composite agitation) in which the rotating shaft is rotated at the time of pulling and the pulling is performed while repeating the vertical movement by the forced lifting means. However, the conventional structure lacks a configuration in which the earth and sand near the root of the stirring blade and the sand and sand on the tip side of the stirring blade are mixed as the original soil, and it is difficult to further increase the degree of mixing. Moreover, in the mixed ejector discharge system of FIG. 9, it is possible to disperse the improvement material in the entire improvement area by entraining the improvement material in the air and discharging it in the form of a mist, and the soil can easily move due to the air lift effect. Although there was an effect of promoting the rise of soil, there was a need for improvement in order to make more effective use.

  The object of the present invention is to improve the mixing efficiency by moving the original soil, that is, the earth and sand, up and down and right and left by the helical ribbon wing from the above background, and when the soil layer changes in the vertical direction, different soil layers are formed. An object of the present invention is to provide a ground mixing treatment apparatus capable of stabilizing the properties of earth and sand by mixing and a mixing treatment method using the same. Other purposes will be clarified in the following description.

  In order to achieve the above object, a first aspect of the present invention is directed to a rotatable rotation shaft, excavation means provided on the lower end side of the rotation shaft, and provided on the upper side of the excavation means so as to protrude substantially perpendicular to the rotation axis. A stirring means having a stirring blade provided; a discharge means provided in the stirring blade; and a supply pipe that is piped along the rotating shaft and that allows the improved material to be jetted together with compressed air from the discharge means. The agitating means is a spiral or helical device provided on the upper side of the agitating blade, wherein the projecting dimension in the radial direction of the rotating shaft becomes maximum at the lower end side and gradually decreases toward the upper side. It is characterized by having a helical ribbon wing having a shape and having an air rising opening penetrating vertically.

  In the above-described present invention, the “stirring blade” may be a blade having a plate shape projecting substantially perpendicularly to the outer periphery of the rotating shaft as shown in the form, and penetrates in the horizontal direction as illustrated in FIG. A wing having an opening for kneading (referred to as an open wing) and a structure having a co-rotation preventing wing provided inside the kneading opening window and rotatable about the shaft are also included. The “discharge means” may be any structure as long as the improved material is jetted together with the compressed air, such as the jet port as illustrated in FIG. 8B, as illustrated in FIGS. 9B and 9C. For example, a mixing ejector or a nozzle.

The present invention as described above is more preferably embodied as follows. That is,
(A) The helical ribbon blade has a configuration in which the projecting dimension in the radial direction of the rotating shaft is substantially the same or slightly shorter at the lower end side than the stirring blade, and the upper end side is ½ or less of the lower end ( Claim 2).
(A) The opening is provided near the periphery of the rotating shaft and is formed to have a size of 50% or more of the blade area.

  On the other hand, the invention according to claim 4 uses the ground mixing treatment apparatus according to any one of claims 1 to 3 in the process of penetrating and / or pulling into the soft ground while rotating the rotating shaft. While mixing the improved material and in-situ soil sprayed from the discharge means by the stirring means, the ground mixing processing method with the rise along the rotation axis of the compressed air contained in the improved material, In the mixing by the agitating means, the improving material and the in-situ soil are agitated by the rotation of the agitating blades with a movement in the rotation direction within the horizontal region, and the improving material from the rotation of the helical ribbon blade and the discharging means. Along with the movement in the left and right and up and down directions by the upward flow of the compressed air injected along with the opening, the agitation is performed.

  In the invention of claim 1, as specified in the mixing treatment method of claim 4, for example, when the improving material is injected at a high pressure from the discharge means together with the compressed air, the injected improving material becomes the in situ soil and the stirring blade. Rotation is mixed with movement in the rotation direction exclusively in the horizontal region, and mixing with movement in the left and right and up and down directions due to the rotation of the helical ribbon blade and the upward flow through the air opening contained in the improvement material Thus, the mixing efficiency can be improved by an amount corresponding to the helical ribbon blade as compared with the conventional apparatus.

  In other words, the helical ribbon blade of the present invention moves, for example, the improved material mixed with the stirring blade and the in-situ soil further in the vertical direction in the process of penetration of the rotating shaft, or differs depending on the vertical movement. By mixing layers (for example, the clay layer on the lower side and the humus soil layer on the upper side as non-land), it is possible to stabilize the mixing property and to suppress the variation in improved quality. In addition, the helical ribbon wing efficiently moves the outer earth and sand away from the rotation axis around the rotation axis, moving the improvement material and the original soil in the horizontal direction and opening the air contained in the improvement material. Ascending flow, that is, vertical movement by an air lift is given, and as a result, the mixing efficiency is improved, and different soil layers are mixed on the land, so that a more stable improved quality can be obtained.

  The inventions of claims 2 and 3 specify details of the helical ribbon wing. Among them, in the helical ribbon wing according to the second aspect, when the lower end side is wide and the upper end side is narrowed, it becomes easy to move the outer earth and sand away from the rotation axis to the vicinity of the rotation axis. From various tests, in order to make it easier to move the outer earth and sand to the rotation axis, that is, to the inner side, the result was that it was preferable to make the upper end side 1/2 or less of the lower end as the blade shape of the helical ribbon blade. . The length of the helical ribbon blade is preferably 2 m or longer, and usually about 2 to 3 m.

  In the invention of claim 3, when the opening of the helical ribbon blade is close to the periphery of the rotating shaft and is formed to have a size of 50% or more of the blade area, the upward flow of air, that is, the air lift effect, Certain earth and sand can easily move, and a good stirring action with the improving material can be obtained.

  In the invention of claim 4, as the ground mixing method, the advantages of the above-described stirring and mixing apparatus of claims 1 to 3 can be obtained. Specifically, in addition to the conventional mixing and stirring by the stirring blade, the mixing efficiency can be improved by the amount of mixing and stirring with the movement in the left and right and up and down directions by the rotation by the helical ribbon blade and the upward flow through the air opening.

It is a front view which shows the principal part of the ground mixing processing apparatus of invention form. (A) And (b) is the top view and bottom view of the mixing processing apparatus of FIG. It is a left view of the stirring and mixing treatment apparatus of FIG. It is a schematic diagram for demonstrating the action | operation of the mixing treatment construction method when the said mixing treatment apparatus is used. It is a front view which shows the modification 1 of the said mixing processing apparatus. It is a front view which shows the modification 2 of the said mixing processing apparatus. It is a front view which shows the modification 3 of the said mixing processing apparatus. (A) And (b) is FIG. 1 and FIG. 3 disclosed by patent document 1. FIG. (A) to (c) FIGS. 1, 4 and 6 disclosed in Patent Document 2. FIG.

  The present invention will be described below with reference to the drawings. FIGS. 1 to 4 show a ground mixing apparatus as an embodiment, and FIGS. 5 to 7 show modifications 1 to 3. FIG. In the following description, after clarifying the mixing processing apparatus shown in FIGS. 1 to 4 and the mixing processing method using the apparatus, modifications 1, 2, and 3 will be referred to.

(Equipment structure) The ground mixing apparatus shown in FIGS. 1 to 4 is an example of a two-axis configuration, and includes two rotating shafts 1 and 1 that are moved up and down synchronously by a construction machine (not shown) and each rotation Excavation blade 2 which is excavation means provided at the lower end of shaft 1, three-stage agitating blades 3 A, 3 B, 3 C which constitute agitation means and project substantially at right angles to rotating shaft 1 and the uppermost agitation The helical ribbon blade 4 provided in the upper shaft portion from the blade 3C, the mixing ejector 5 serving as the discharge means provided in the lowermost stirring blade 3A, and the mixing ejector 5 piped along the rotary shaft 1 are improved. Supply pipes 6a and 6b that enable the material to be injected together with compressed air, and a co-rotation prevention plate 7 provided between the rotary shafts 1 are provided. These details will be clarified below.

  First, the rotating shaft 1 has a substantially cylindrical shape and is rotated forward and backward by a drive mechanism (not shown). The upper end side 1a is formed in a polygonal shape, and the lower end side 1b is formed in a slightly smaller diameter. ing. The upper end side 1a is a connection part connected to the next rotating shaft or drive mechanism. The lower end side 1b includes a shaft 12 constituting excavation means mounted in the lower end cylinder, a stirring blade 3A, a co-rotation prevention plate 7, a stirring blade 3B, and a co-rotation prevention provided in order from bottom to top. It has the board 7 and the stirring blade 3C. Further, the rotary shaft 1 is provided with a helical ribbon blade 4 around the stirring blade 3C. An improvement material supply pipe 6a, an air supply pipe 6b, and the like are provided in the rotary shaft 1. The improving material is pumped from the solidification system supply means to the supply pipe 6a. Compressed air is pumped from the compressed air supply means 12 to the supply pipe 6b (see FIG. 8A).

  Each of the stirring blades 3 </ b> A to 3 </ b> C has an elongated plate shape, and is provided in a pair of left and right with respect to the mounting cylinder 13. The left and right stirring blades are firmly coupled and supported on the mounting cylinder 13 by a reinforcing material whose base end side is not shown. The stirring blades 3A, 3B, 3C are pivotably movable integrally with the rotary shaft 1 in a state where the mounting cylinder 13 is positioned and fixed around the lower end side 1b. Further, the left and right stirring blades are around the mounting cylinder 13 fitted to the rotary shaft 1 and are fixed by welding or the like with a slight deviation as shown in FIG. Thus, the left and right ends are formed in a C shape on one side and an inverted C shape on the other side. Each stirring blade may be reinforced and fixed to the mounting cylinder 13 with a fixing plate (not shown) or the like as necessary.

  The mixing ejector 5 is provided in one stirring blade among the pair of stirring blades 3C. Although the details of the mixing ejector 5 are omitted, the mixing ejector 5 includes an introduction cylinder portion 14, an ejection portion 17, and an attachment portion 18 as in FIG. 9B. In the introduction cylinder portion 14, a rear air supply portion 14b and a front improvement material supply portion 14a are partitioned by a valve mechanism or the like, and inlets 13a and 13b are provided in the supply portions 14a and 14b. This valve mechanism is fixed to the inner periphery of the introduction cylinder part 14, and is capable of introducing compressed air introduced into the air supply part 14b into the inside, the inside of the valve case 15 and the improvement material supply part 14a side, And a valve member 16 for opening and closing. 1 is connected to the inlet 13a, and the supply pipe 6b is connected to the inlet 13b via a connection pipe or the like. The valve member 16 blocks between the supply parts 14a and 14b. When the air supply part 14b reaches a predetermined pressure, the valve member 16 is switched to an open state against the biasing pressure of the spring member 16a to supply compressed air. It introduces into the supply part 14a side from the 14b side. The improved material introduced into the supply unit 14a is put on the compressed air introduced from the supply unit 14b, is led out toward the ejection unit 17, and is injected at a high pressure. The above-described mixing ejector 5 is positioned and disposed at a substantially intermediate position on the left and right of the stirring blade 3C so that the jet port 13c of the injection unit 17 faces the rotation direction during the mixing operation of the stirring blade 3C. It is fixed (see Document 2 for details).

  On the other hand, each co-rotation prevention plate 7 is configured to connect the rotary shafts 1 on both sides to serve as a steady stop for the rotary shafts. The cylindrical body 17 and the cylinder disposed around each rotary shaft 1. A pair of brackets 8, 8 attached to the shape body 17 are provided, and the left and right ends of each rotating shaft 1 are connected and supported in a state of being sandwiched between the brackets 8. The cylindrical body 17 has an inner diameter that is slightly larger than the outer diameter of the rotating shaft 1, and is rotatably assembled to a fixed height position of the rotating shaft 1 by upper and lower stoppers 18 provided on the rotating shaft 1.

  The helical ribbon blade 4 has a spiral or helical shape in which the projecting dimension in the radial direction of the rotary shaft 1 is set to the maximum at the lower end side, and gradually decreases toward the upper side. have. In other words, the helical ribbon blade 4 is such that the upper and lower end portions 4 a and 4 b are fixed around the rotating shaft 1, and a plurality of pieces 4 c and 4 d extending inward are fixed around the rotating shaft 1. It has become. The air raising opening 14 is provided in a window shape between the upper end 4a and the piece 4c, between the piece 4c and the piece 4d, and between the piece 4d and the lower end 4b.

  More specifically, as schematically shown in FIG. 4, the helical ribbon wing 4 makes the outer earth and sand away from the rotary shaft 1 by the rotation of the rotary shaft 1 close to the rotary shaft 1, that is, left and right as the soil in the original position. It is devised in a shape that makes it easier to move to the upper end 4a side, that is, up and down. From various tests, it is preferable that the projecting dimension in the radial direction of the rotary shaft 1 is set so that the lower end side is substantially the same as or slightly shorter than the stirring blade, and the upper end side is set to ½ or less of the lower end. became. The helical ribbon blade 4 is provided so that the length L1 is equal to or longer than the distance L2 between the lowermost stirring blade 3C and the uppermost stirring blade 3A among the stirring blades as shown in FIG. ing. However, this length L1 is generally preferably set to about 2 to 3 m.

  The opening 14 is a hole for insertion that keeps rising, that is, the air lift is good along the rotating shaft 1 when compressed air is jetted together with the improving material in the ground. In this configuration, as the mixing operation of the helical ribbon blade 4, as described above, the outer earth and sand away from the rotating shaft 1 is moved to the rotating shaft 1, that is, to the left and right to be mixed with the improved material, and in addition, the upward flow of air To further mix with the improved material. That is, the mixing action by the air lift effect is maintained well. From various tests, it is preferable that the opening 14 is provided near the periphery of the rotary shaft 1 and formed to have a size of 50% or more of the blade area.

(Construction method) Next, the processing operation of the above-described mixing processing apparatus will be outlined. The normal construction procedure is to create an improved pile through a positioning process, an improved material injection / penetration stirring process, a bottoming confirmation / tip treatment process, and a drawing stirring process. In the positioning step, the mixing processing apparatus is moved to the construction location by the construction machine and positioned. In the improvement material injection / penetration stirring step, the penetration operation is continuously performed while the rotary shaft 1 is rotated, and the mixing operation is performed in this penetration process. That is, in this operation, the improved material is pumped from the solidification supply means through the supply pipe 6a and the compressed air is pumped to the mixing ejector 5 through the supply pipe 6b. In the mixed ejector 5, when the supply portion 14 b reaches a predetermined pressure as described above, the valve member 16 is switched to the open state against the biasing pressure, and compressed air is introduced from the supply portion 14 b to the supply portion 14 a side. The improved material introduced into the supply unit 14a is put on the compressed air and ejected from the ejection unit 17 toward the ground (see Document 2 for details). In the bottoming confirmation / tip processing step, after confirming that the tip of the rotating shaft 1 has reached the support layer, the injection of the improved material is stopped, the rotating shaft 1 is pulled out by a predetermined dimension, and re-penetrated to perform tip processing. Do. In the pulling and stirring step, the rotary shaft 1 is pulled out while being reversely rotated. Thereafter, the mixing processing apparatus is moved to the next construction position.

  By the way, in the above rotating shaft 1, it has the helical ribbon blade | wing 4 with stirring blade 3A-3C as a stirring means. For this reason, in this mixing operation, the improvement material and the in-situ soil are stirred by the rotation of the stirring blades 3 </ b> A to 3 </ b> C with a movement in the rotation direction in the horizontal region, and the helical ribbon blade 4 is rotated and discharged. Stirring is performed with movement in the left and right and up and down directions by the upward flow through the opening 14 of the compressed air injected together with the improving material from the discharge portion of the ejector 5. In other words, as the operation of the helical ribbon blade 4, for example, in the process of penetration of the rotary shaft 1, the improved material mixed with the stirring blades 3A to 3C and the in-situ soil are further moved upward, It is also possible to mix different soil layers (for example, the clay layer on the lower side and the humus soil layer on the upper side as non-land), thereby stabilizing the mixing properties of the soil layers and improving the quality of the soil. Variations can be kept small.

  In the above-described mixing treatment method, the improvement material ejection time may be any of the penetration process, penetration and extraction process, and extraction process of the rotating shaft 1. Here, when the stirring blades are provided in a plurality of stages above and below, the mixing ejector 5 and the nozzle 20 shown in FIG. 8C are designed as necessary. In addition to the fluid such as cement milk, the solidification type improving material can also be discharged with accompanying compressed air even in a powder system such as quick lime or cement.

(Modifications) FIGS. 5 to 7 show three examples in which the above-described mixing apparatus is changed to a single-axis configuration. In this description, the same reference numerals are assigned to the same members and parts to avoid duplication as much as possible, and the changes are clarified.

  In FIG. 5, the ground mixing treatment apparatus includes a single rotating shaft 1 that is lifted and lowered by a construction machine (not shown), an excavating blade 2 that is excavating means, and a stirring means that is substantially perpendicular to the rotating shaft 1. The three-stage stirring blades 3A, 3B, 3C and the helical ribbon blade 4 provided on the upper shaft portion of the uppermost stirring blade 3C and the discharge means provided on the lowermost stirring blade 3A. The mixing ejector 5 is provided with supply pipes 6a and 6b that are piped along the rotary shaft 1 so that the improved material can be injected from the mixing ejector 5 together with the compressed air, and a plurality of co-rotation prevention plates 7A. Each co-rotation prevention plate 7A is arranged around the rotating shaft 1 in that it is arranged between the agitation blades 3A and 3B and between the agitation blades 3B and 3C, respectively, as compared with the co-rotation prevention plate 7. The same in that it has a cylindrical body 17 and a pair of brackets 8, 8 attached to the cylindrical body 17, and is connected and supported in a state where the corresponding end is sandwiched between the brackets 8 with respect to the rotating shaft 1. . However, the left and right co-rotation prevention plates 7A are formed to be slightly longer than the full size of each stirring blade, and are set so as to be difficult to rotate in a state of being penetrated into the ground.

  In FIG. 6, the ground mixing treatment apparatus is simplified by omitting the co-rotation prevention plate 7A as compared with the apparatus structure of FIG. 5 and changing the three-stage stirring blade to the one-stage stirring blade 9. Yes. That is, the left and right stirring blades 9 are each substantially U-shaped, and the upper and lower ends are fixed to the periphery of the mounting cylinder 13A by welding or the like. The left and right stirring blades 9 define a kneading opening window 19 between the mounting cylinder 13A and the rotary shaft 1. In this apparatus structure, the improvement material and the soil in the original soil are rotated by the rotation of the opening window 19 in the process of stirring the improvement material and the original soil by the rotation of the stirring blades 9 with the movement in the rotation direction within the horizontal region. It is kneaded from one side that is the forward direction to the other side that is the post-rotation direction, and the degree of mixing can be improved by the kneading action. As an example of further developing the above device structure, as disclosed in Japanese Patent No. 3287789, a small co-rotation prevention plate or a similar member can be rotated inside the opening window 19 with respect to the mounting cylinder 13A and the like. In addition, a plate-like stirring blade such as the stirring blade 3A or a rotatable co-rotation prevention plate such as the co-rotation prevention plate 7A is added between the helical ribbon blade 4 and the stirring blade 9 as well. It may be.

  In FIG. 7, the mixing processing apparatus for the ground is different from the apparatus structure of FIG. 6 in that the stirring blade 9A, the excavating blade as the excavating means, and the mixing ejector as the discharging means are changed. That is, the left and right agitating blades 9A are fixed to the periphery of the mounting cylinder 13A by welding or the like, a plurality of excavating blades 2A mounted on the lower edge side, and provided in the plate thickness with an injection port at the blade tip surface. It has a jet nozzle 5A that is exposed. The excavating blade 2A is mounted on the lower end side 1b of the rotating shaft 1 together with the stirring blade 9A. The excavating means of the present invention is not limited to the excavating blade 2A provided on the lower end side of the rotating shaft as in this configuration example, but also includes an excavating blade 2A provided on the lower edge side of the stirring blade 9A. Moreover, since the jet nozzle 5A has the jet nozzle exposed at the tip surface of the stirring blade 9A, excavation and stirring of the in-situ soil is performed by the injection force when the improved material is jetted together with the compressed air. It can be further expanded in the radial direction than the region.

  Note that the above embodiments and modifications do not limit the present invention. The present invention may be provided with the technical elements specified in claim 1, and the details can be variously changed as necessary. For example, the multi-axis configuration of the rotating shaft 1 includes three or more axes, or the opening configuration of the helical ribbon blade 4 is formed in a spiral continuous frame shape.

1... Rotating shaft (1a is the upper end side, 1b is the lower end side)
2 ... Drilling blade (Drilling means)
2A ・ ・ ・ ・ Drilling blade (Drilling means)
3A ・ ・ ・ ・ Agitating blade
3B ··· Stirring blade (stirring means)
3C ... Stirring blade (stirring means)
4 ... Helical ribbon blade (stirring means: 14 is the opening for air rise)
5. Mixing ejector (discharge means)
5A ... Spray nozzle (discharge means)
6a ... Supply pipe for improvement material 6b ... Supply pipe for compressed air 7 ... Co-rotation prevention plate 8 ... Co-rotation prevention plate 9 ... Agitation blade Means: 19 is an opening window for kneading
9A ... ・ Agitating blade (Agitating means)

Claims (4)

  A rotating shaft capable of rotating, an excavating means provided on the lower end side of the rotating shaft, an agitating means provided on the upper side of the excavating means and projecting substantially perpendicularly to the rotating shaft; and the stirring A ground mixing and processing apparatus comprising: discharge means provided on a blade; and a supply pipe that is piped along the rotating shaft and that enables the improvement material to be injected together with compressed air from the discharge means. The means is provided on the upper side of the agitating blade, has a spiral or helical shape in which the projecting dimension in the radial direction of the rotating shaft gradually decreases toward the upper side at the lower end side, and the air rises vertically. A ground mixing treatment apparatus having a helical ribbon wing having an opening for use.   The helical ribbon blade has a protruding dimension in a radial direction of the rotating shaft, the lower end side being substantially the same as or slightly shorter than the stirring blade, and the upper end side being 1/2 or less of the lower end. The ground mixing treatment apparatus according to 1.   3. The ground mixing apparatus according to claim 1, wherein the opening is provided near the periphery of the rotating shaft and has a size of 50% or more of a blade area. Using the ground mixing and mixing apparatus according to any one of claims 1 to 3, the improvement material and the raw material injected from the discharge means in the process of penetration and / or extraction into the soft ground while rotating the rotating shaft. The ground soil is mixed by the stirring means, and is a ground mixing treatment method with a rise along the rotation axis of the compressed air contained in the improvement material,
In the mixing by the agitating means, the improving material and the in-situ soil are agitated by the rotation of the agitating blades with a movement in the rotation direction within the horizontal region, and the improving material from the rotation of the helical ribbon blade and the discharging means. A mixing treatment method characterized by stirring with a movement in the left and right and up and down directions by an upward flow of compressed air injected along with the opening.

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