JP4107338B2 - Multi-axis composite stirring method - Google Patents

Description

  The present invention relates to a ground improvement technique, and more particularly, to an apparatus and a method for performing ground improvement by so-called combined stirring using both mechanical stirring and jet stirring.

  As this type of apparatus and method, Patent Document 1 includes a drilling blade and a stirring blade at the tip of the rod, a low-pressure discharge port near the tip of the rod, and a high-pressure discharge port at the tip of the drilling blade. A construction method using a ground improvement device having a configuration is disclosed. This is because the rod is fed into the ground while discharging the improved material from the low pressure discharge port at a low pressure, and the central improvement column is formed by stirring and mixing the improved material and soil with the stirring blade, and then the high pressure discharge port. The outer improvement pillar is constructed outside the central improvement pillar by stirring and mixing by high-pressure injection of the improvement material.

Further, in Patent Document 2, the shaft body of a rod provided with a stirring blade is configured in a screw auger shape, and at the time of high-pressure injection of an improved material, a jet agitating part is formed while soiling the core part soil by the screw auger A ground improvement method is disclosed.
Furthermore, Patent Document 3 discloses a construction method in which the improved body block is integrally wrapped using a multiaxial high-pressure jet stirring ground improvement device having a configuration in which three screw auger-shaped rods are arranged side by side. There is disclosure.
Japanese Examined Patent Publication No. 6-37767 Japanese Patent No. 3125244 JP-A-2005-155034

  Since the rod shown in Patent Document 1 has a single axis, efficient construction cannot be expected, and since a large amount of improved material is simply injected into the ground at a high pressure, adverse effects such as displacement and expansion of the surrounding ground cannot be ignored. .

Although the thing shown by patent document 2 can suppress a surrounding ground displacement by forcibly discharging with a screw auger, since it is a single axis like what is shown in patent document 1, workability and economical efficiency The situation is the same in terms of effectiveness.
Although the one shown in Patent Document 3 includes a triaxial screw rod, the workability is improved compared to those of Patent Documents 1 and 2, and it can be applied to large-scale construction. Are simply arranged side by side as they are simply operated synchronously, so that not only the whole device is unreasonably large, but also the setting of the supply amount of the improved material and the control of the amount of soil discharge are not necessarily limited. It cannot be carried out rationally, and in particular when applied to large-scale construction, there are difficulties in terms of economy and workability, and it has not been put into practical use.

In view of the above circumstances, an object of the present invention is to provide an effective and appropriate construction method capable of economically and efficiently performing ground improvement by combined stirring of mechanical stirring and jet stirring.

The multi-shaft composite agitation method of the present invention includes a stirrer blade provided at the tip of the agitator so as to construct the improved body by performing mechanical agitation with a stirrer blade while performing jet agitation by injecting the improved material into the ground. The main rotating shaft is provided with an odd number of rotating shafts greater than or equal to the number of shafts, the rotating shafts comprising at least two main rotating shafts and at least one auxiliary rotating shaft, with the main rotating shafts disposed on both sides. And a stirrer blade provided at the tip of the main rotating shaft are provided with a main injection port for injecting the improved material into the ground, and the tip of the sub rotating shaft. The stirrer provided with a sub-injection port for injecting the improved material at a pressure lower than the injection pressure from the main injection port provided on the main rotation shaft, and the shaft portion of the sub-rotation shaft has a surrounding basically the use of multi-axis composite stirring device provided with a spiral to discharge soil pushing up the soil To.
In the multi-shaft composite stirring apparatus used in the multi-shaft composite stirring method of the present invention, the positions of the main injection port and the sub injection port provided on the main rotation shaft and the sub rotation shaft are set in relation to the injection process. In the case of injection at the time of pulling out, the position of the sub-injection port is set below the position of the main injection port. Conversely, in the case of injection at the time of penetration, the position of the sub-injection port is set to the position of the main injection port. Is set higher than .
In particular, in the multi-shaft composite stirring device used in the multi-shaft composite stirring method of the present invention, the stirring blades provided in the main rotating shaft and the sub-rotating shaft are constituted by the upper stirring blade and the lower stirring blade, respectively, and the main rotating shaft It is better to provide a main injection port on the lower stirring blade provided at the tip of the shaft and a sub-injection port on the lower stirring blade provided at the tip of the sub-rotating shaft. Is set below the position of the lower agitating blade provided at the tip of the main rotating shaft below the position of the lower agitating blade provided at the tip of the main rotating shaft. The position of the lower stirring blade provided at the tip of the main rotating shaft may be set higher than the position of the lower stirring blade provided at the tip of the main rotating shaft.

The multi-shaft composite stirring method of the present invention is to improve the ground using the multi-shaft composite stirrer described above, and is a spiral provided to the sub-rotating shaft while being mechanically stirred by the stirring blades provided to the main rotating shaft and the sub-rotating shaft. While discharging the soil, the improvement material is injected from the main injection port provided in the main rotation shaft, and the improvement material is injected from the sub injection port provided in the sub rotation shaft at a pressure lower than the injection pressure from the main injection port. By forming the improved body, the improved body is provided with a mechanical stirring improving portion integrally formed around the main rotating shaft and the sub rotating shaft and a mechanical stirring improving portion formed around the main rotating shaft on the outside. A main injection agitation improving portion formed in an enlarged state and a sub-injection formed in the same diameter as the main injection agitation improving portion in a state where the mechanical agitation improving portion formed around the auxiliary rotating shaft is expanded outward. Install in a shape with a stirring improvement part Basic to that.
In particular, when jetting is performed at the time of pulling out, after the main rotary shaft and the sub rotary shaft have penetrated into the ground, when the main rotary shaft and the sub rotary shaft are pulled out from the ground, the main rotary shaft and the sub rotary shaft are While performing mechanical stirring with the stirring blades provided respectively, while discharging the soil by the spiral provided in the auxiliary rotating shaft, the improvement material is injected from the main injection port provided in the main rotating shaft to form the main injection stirring improvement part in advance. From the sub-injection port provided on the rotating shaft, the improved material is injected at a lower pressure than the injection pressure from the main injection port, and the sub-injection agitation improvement unit is formed downstream from the main injection agitation improvement unit to improve the improved body. It is characterized by forming.
On the contrary, when injection is performed at the time of penetration, when the main rotary shaft and the sub rotary shaft are penetrated, mechanical stirring is performed by the stirring blades provided on the main rotary shaft and the sub rotary shaft, respectively, while the spiral provided on the sub rotary shaft is used. While performing the earth removal, the improvement material is injected from the main injection port provided in the main rotary shaft to form the main injection agitation improving portion in advance, and the sub injection port provided in the sub rotation shaft from the injection pressure from the main injection port In addition, after the improvement material is formed by injecting the improved material at a low pressure to form the improved body by following the sub-injection agitation improvement part above the main injection agitation improvement part, the main rotation shaft and the auxiliary rotation shaft are pulled out. To do.
In the multi-shaft composite agitation method of the present invention, the rotational speed of the sub-rotating shaft is controlled independently of the main rotating shaft, and the amount of soil discharged by the spiral provided on the sub-rotating shaft is controlled, so that the main rotating It is preferable to promote the flow of the improved soil from the main rotating shaft side to the sub rotating shaft side in the mechanical stirring improving portion integrally formed around the shaft and the sub rotating shaft.
Furthermore, by alternately rotating the main rotation shaft and the sub rotation shaft that are alternately arranged in the opposite direction, the improved soil is continuously formed in the mechanical stirring improvement portion integrally formed around the main rotation shaft and the sub rotation shaft. It is preferable to form a series of stirring streams that flow through.

According to the multi-shaft composite agitation method of the present invention, the improved material is ejected from the main rotating shaft at a high pressure and discharged from the sub rotating shaft at a lower pressure while discharging the soil by the spiral of the sub rotating shaft. In addition, the combined use of mechanical stirring with stirring blades and jet stirring with improved material injection enables efficient construction of improved bodies with large cross-sections, effectively avoiding adverse effects on the surrounding ground, mountain retaining walls, water blocking walls, etc. In contrast, it is possible to construct the improved body in a state of being almost completely adhered.
In addition, the multi-shaft composite stirrer used in the multi-shaft composite stirrer method of the present invention has a structure corresponding to each function of the main rotating shaft and the sub-rotating shaft, so that the entire apparatus is rationally simplified and made compact. It is possible to reduce the price, and it is excellent in operability and controllability and enables high-precision construction. Especially, the position of the main injection port and the sub injection port is set according to the injection process, so it is economical enough And rational construction is possible, and it is particularly suitable for application to large-scale construction.

1 to 3 show a multiaxial composite stirring method according to an embodiment of the present invention.
As shown in FIG. 1, the multi-axis composite agitation apparatus used in the multi-axis composite agitation method of the present embodiment (hereinafter sometimes simply referred to as the multi-axis composite agitation apparatus of the present embodiment) has three rotational axes 1 in parallel. The two rotating shafts 1 on both sides and the central rotating shaft 1 are different in configuration and function from each other.
That is, the two rotating shafts 1 on both sides are the main rotating shaft 1A, and a spiral lower stirring blade 3 that is used for both ground excavation and ground stirring is provided at the foremost part of the rotating shaft 1, and one stage is provided on the upper stage. The upper stirring blade 5 is provided. A main injection port 4 for injecting an improved material (for example, a solidified material such as cement) at a high pressure (for example, about 30 to 60 MPa) is attached to the outer peripheral portion of the lower stirring blade 3 for excavation. It is located slightly above the bit.

On the other hand, the central rotating shaft 1 is a sub-rotating shaft 1B, and a lower stirring blade 6 also used for ground excavation is provided at the foremost end, and an upper stirring blade 7 is provided at the upper stage. The lower stirring blade 6 and the upper stirring blade 7 are each approximately the same diameter as the upper stirring blade 5 in the main rotating shaft 1A, and the lower stirring blade 6 and the upper stirring blade 7 in the sub rotating shaft 1B are respectively the main rotating shaft 1A. Is positioned slightly below the lower agitating blade 3 and the upper agitating blade 5 and rotates while wrapping the rotation trajectory without mutual interference.
Further, a spiral 8 for pushing up and discharging the surrounding soil is provided at the shaft portion of the auxiliary rotary shaft 1B.
The lower stirring blade 6 of the sub-rotating shaft 1B is also provided with a sub-injecting port 9 for injecting the improved material. The injection pressure from the sub-injecting port 9 is provided on the main rotating shaft 1A. It is set to a low pressure (for example, about 10 MPa) as compared with the injection pressure from the main injection port 4 (for example, about 30 to 60 MPa as described above).
In addition, since the lower stirring blade 6 in the sub-rotating shaft 1B is located slightly below the lower stirring blade 3 in the main rotating shaft 1A, the sub-injection port 9 provided in the lower stirring blade 6 of the sub-rotating shaft 1B. Is positioned slightly below the main injection port 4 provided in the lower stirring blade 3 of the main rotating shaft 1A. The sub-injection port 9 may have the same structure as that of the main injection port 4, but since the injection pressure from the sub-injection port 9 is set lower than the injection pressure from the main injection port 4, pressure resistance performance and It is also possible to reduce wear resistance performance, thereby reducing costs. Further, a supply mechanism (not shown) for feeding the improved material to the sub-injection port 9 may be set so that the injection pressure can be freely set in a range lower than the injection pressure from the main injection port 4. .

  Further, in the present embodiment, as shown in FIG. 1, the improvement material is discharged at a low pressure to a position slightly below the upper stirring blades 5 and 7 in the shaft portions of the main rotating shaft 1A and the sub rotating shaft 1B. In the case where the discharge ports 11 (11a, 11b) are respectively provided and the supply amount of the improvement material is insufficient only by the injection from the main injection port 4 or the sub injection port 9, any of the discharge ports 11 is selected. One or both of them can be supplementarily supplied with the improved material at a low pressure (for example, about 3 MPa or less).

The multi-shaft composite agitation apparatus of this embodiment includes mechanical stirring and mixing by the lower stirring blades 3 and 6 and the upper stirring blades 5 and 7 provided in both the main rotating shaft 1A and the sub rotating shaft 1B, and the main rotating shaft. By the combined use of high-pressure jet agitation mixing by high-pressure injection of the improved material from the main injection port 4 provided in 1A and low-pressure injection agitation mixing by low-pressure injection of the improvement material from the sub-injection port 9 provided in the auxiliary rotating shaft 1B, The improvement body 10 of a planar shape as shown in FIG.1 (b) is constructed.
That is, the improved body 10 is a series of mechanical stirring improvement portions 10a formed integrally around the main rotating shaft 1A and the auxiliary rotating shaft 1B by stirring and mixing with the lower stirring blades 3 and 6 and the upper stirring blades 5 and 7. A main injection agitation improving portion 10b formed on both outer sides of the mechanical agitation improving portion 10a by high pressure injection from the main injection port 4, and a mechanical agitation by low pressure injection from the sub injection port 9. A sub-injection agitation improving part 10c having a diameter equivalent to that of the main injection agitation improving part 10b in a state where it is expanded outward on both outer sides of the central part of the improvement part 10a.

The main rotary shaft 1A and the sub rotary shaft 1B are independently rotated by a dedicated drive source 12 (see FIG. 2), and their rotation speeds can be controlled independently by an inverter or the like.
And the rotation direction of the central auxiliary rotating shaft 1B is always set to the soil removal direction (that is, the rotation direction that pushes up the surrounding soil upward by the spiral 8), thereby penetrating the entire apparatus into the ground, and When the improvement material is injected into the ground from the main injection port 4 and the sub-injection port 9 and mixed by injection stirring, the sub-rotating shaft 1B positively discharges the soil from the vicinity of the center of the mechanical stirring improvement unit 10a. As a result, an excessive increase in the earth pressure is suppressed, and accordingly, the flow of the improved soil moves from both sides of the mechanical stirring improving portion 10a toward the center side (that is, from the main rotating shaft 1A side to the sub rotating shaft 1B side). As a result, an excellent stirring and mixing effect can be obtained throughout the mechanical stirring improving portion 10a.

  At that time, as shown in FIG. 1, the rotation direction of the two main rotation shafts 1A on both sides is set so as to always rotate in the direction opposite to the sub rotation shaft 1B. As a result, the three rotation shafts 1 alternately It may be set to rotate in the reverse direction. By such setting of the rotation direction, a series of stable stirring flows are formed such that the improved soil continuously flows while meandering throughout the mechanical stirring improving portion 10a as shown in FIG. The stirring and mixing efficiency in the entire stirring improving portion 10a can be sufficiently improved.

A specific example of the standard process by the multi-axis composite agitation apparatus of this embodiment is shown in FIG.
The entire apparatus penetrates into the ground as shown in (a) to (c) while rotating each rotary shaft 1 in the rotation direction described above. At that time, the amount of rotation of the auxiliary rotary shaft 1B is appropriately controlled in consideration of the penetration speed, and the earth corresponding to the device volume is discharged by the spiral 8.
In order to make the formation of the main injection agitation improving portion 10b and the sub injection agitation improving portion 10c by injection of the improvement material in the latter stage (at the time of drawing) more reliable, at this time, either the main injection port 4 or the sub injection port 9 is used. It is better to loosen the ground by spraying only water from one or both sides.
Furthermore, when it is predicted that the supply amount of the improved material will be insufficient only by the injection at the latter stage (at the time of drawing), or depending on the ground conditions, it is provided at the shaft portion of the main rotating shaft 1A or the sub rotating shaft 1B. What is necessary is just to supply a desired amount of the improving material from both or one of the discharge ports 11 (11a, 11b) at a low pressure.

When the tip of the apparatus reaches a predetermined depth as shown in (c), the direction of rotation of each axis is maintained as it is, and the improvement material is supplied from the main injection port 4 provided on the main rotating shaft 1A with a high pressure (for example, 30 to 60 MPa). And the improvement material is injected at a lower pressure (for example, 10 MPa) from the sub-injection port 9 provided in the sub-rotating shaft 1B, and the entire apparatus is pulled up as shown in (d) to (e). Go.
At that time, the rotational speed of the sub-rotating shaft 1B is appropriately controlled according to the injection amount of the improvement material, and the soil is discharged by the spiral 8 to suppress an excessive increase in earth pressure caused by the improvement material injection, and at the same time, improve the mechanical stirring. A flow of improved soil from both sides of the portion 10a toward the center, and a series of stable stirring flows that continuously flow while meandering throughout the mechanical stirring improvement portion 10a as described above, Mix thoroughly with stirring. In addition, when air is used together for the injection of the improved material, the soil is muddy, and the treatment is necessary. Therefore, it is preferable to inject only the improved material without using air.
Thereby, not only at the time of penetration but also at the time of withdrawal, the above-described series of stirring flow is formed and the ground is sufficiently loosened, and then the improvement material is injected from the main injection port 4 and the sub injection port 9, respectively. Therefore, the mechanical stirring improvement part 10a is integrally formed around the main rotating shaft 1A and the sub-rotating shaft 1B by both of the mechanical stirring and the jet stirring, and at the same time, on both outer sides of the mechanical stirring improving part 10a. The main injection agitation improving portion 10b by the high pressure injection from the main injection port 4 is formed in a state of expanding outward, and the sub injection by the low pressure injection from the sub injection port 9 is formed on both outer sides of the central portion of the mechanical stirring improvement portion 10a. The stirring improvement part 10c is formed in the state which expands outside, and, thereby, the cross-sectional improvement body 10 as shown in FIG.1 (b) is constructed efficiently.

  In this case, it is useless to inject from the auxiliary injection port 9 at the same high pressure as the main injection port 4. That is, by performing injection at the time of pulling out as described above, the main injection agitation improving portions 10b on both sides are formed in advance by high-pressure injection from the main injection port 4 located above the sub-injection port 9, The construction range of the subsequent sub-injection agitation improving portion 10c formed between them is reduced, and therefore the diameter of the sub-injection agitation improving portion 10c is mainly set even if the injection pressure from the auxiliary injection port 9 is relatively low. It can be made equal to the diameter of the jet stirring improvement part 10b. In other words, when the injection pressure from the sub-injection port 9 is set to a high pressure equivalent to the main injection pressure 4, the diameter of the sub-injection stirring improvement part 10c becomes larger than necessary, and the improvement material is merely wasted.

  When the improvement body 10 up to the desired depth is constructed, as shown in (f), the entire apparatus is lifted to the ground and moved to the next construction position, and thereafter, the same process is repeated to construct another improvement body 10.

Show the steps as pattern 1 in Table 1, is also conceivable step of performing injection during penetration, as shown in Table 1 as the pattern 2 as other patterns as described below. In any case, an optimal process may be appropriately set in consideration of the ground condition and other various conditions.

  As described above, by performing the above-described process using the apparatus of the present embodiment, the large-section improved body 10 can be efficiently constructed in a single process, and the displacement and expansion of the surrounding ground, etc. The adverse effects of can be avoided. Then, as shown in FIG. 3, by arranging the improved bodies 10 along the retaining wall W, the main injection stirring improvement part 10 b and the sub-injection stirring improvement part 10 c can be almost completely adhered to the retaining wall W. It is.

Particularly, the improved material is injected at high pressure from the two main rotating shafts 1A on both sides, and the improved material is injected at low pressure from the central rotating shaft 1B, and the soil is actively discharged by the spiral 8 of the auxiliary rotating shaft 1B. Since the main rotary shaft 1A and the sub rotary shaft 1B are configured according to their functions, the entire apparatus can be rationally simplified, made compact, and reduced in price. It is excellent in operability and controllability and can be applied with high precision, so that it is sufficiently economical and rational.
Therefore, according to this, not only the original ground improvement aimed at improving soft ground, but also liquefaction prevention measures for liquefied ground, strengthening of foundation ground of various structures, against mountain retaining walls and water blocking walls It can be widely applied as various ground improvement techniques for the purpose of ensuring stability, etc., and by forming the improved body 10 continuously in the longitudinal direction, it can function as a mountain retaining wall or a water blocking wall. In particular, it is suitable for application to large-scale construction.

  Although one embodiment of the present invention has been described above, the above embodiment is merely a preferred example, and the present invention is not limited to the above embodiment, and the present invention is not limited to the gist of the present invention. Various modifications and applications are possible.

For example, the shape and dimensions of the improved body 10 are the same as the diameters of the lower stirring blades 3 and 6 and the upper stirring blades 5 and 7 as long as the sub-injection stirring improvement portion 10c is formed to have the same diameter as the main injection stirring improvement portion 10b. Needless to say, various modifications can be made by appropriately changing the injection distance of the improved material from the main injection port 4 and the sub injection port 9, the inter-axis distance between the rotary shafts 1, and the like. Is also optional, and may be optimally designed in consideration of various conditions such as the use and purpose of the improved body 10 to be constructed, the improvement rate, and the construction scale.
In particular, in the present invention, as described in the above embodiment, the injection pressure from the sub-injection port 9 needs to be lower than the injection pressure from the main injection port 4. By appropriately setting the injection pressure, it is possible to construct the sub-injection stirring improvement part 10c in a desired size, but the sub-injection stirring improvement part 10c is equivalent to the main injection stirring improvement part 10b as described above. Should be formed to a diameter of
That is, in the above embodiment, as shown in FIG. 3, the size of the sub-injection stirring improvement portion 10c is made equal to that of the main injection stirring improvement portion 10b with the intention of bringing the improvement body 10 into complete contact with the mountain wall W. Thus, the injection pressure from the sub-injection port 9 is set, and the present invention should be set as such.
For reference, the improved body 10 having a shape in which the sub-injection agitation improving portion 10c is reduced as shown in FIG. 4A by further reducing the injection pressure from the sub-injection port 9 is provided. In this case, as shown in (b), the improvement efficiency can be improved by reducing the overlapping loss between the improved bodies when a large number of the improved bodies 10 are arranged in a staggered manner to improve the entire surface. Furthermore, the injection from the sub-injection port 9 may be stopped and only the high-pressure injection from the main injection port 4 may be performed. In this case, an improved body 10 having a glasses shape or a bowl shape is applied as shown in FIG. It is possible to minimize the overlap loss when arranging them in a staggered manner, thereby improving the improvement efficiency.
And since the improved body 10 of a desired shape can be formed only by setting the injection pressure from the sub-injection port 9 as described above, the improved body 10 is continuously applied in the longitudinal direction as shown in FIG. It is possible to carry out both the case of closely contacting the retaining wall W and the case of performing the entire surface improvement by arranging the improved bodies 10 in a staggered manner as shown in FIGS.

In addition, the specific configuration of each part of the multi-shaft composite stirring apparatus of the present invention, particularly the stirring blades provided on each rotary shaft 1, is determined by the upper stirring blades 5, 7 and the lower stirring blades 3, 6 as in the above embodiment. Although it is preferable to configure, the present invention is not limited to this, and the shape and position thereof are arbitrary (of course, it may be one or three or more). Further, the shape, position and number of the lower stirring blades 3 and 6 and the upper stirring blades 5 and 7 provided on each rotary shaft 1, the position and specifications of the main injection port 4 and the sub injection port 9, and the spiral 8 provided on the sub rotation shaft 1B. The presence / absence, position, number of locations, and the like of the discharge ports 11 provided in the shaft portion may be appropriately changed.
For example, in the above embodiment , since the injection is performed at the time of drawing, the length of the sub-rotating shaft 1B is slightly longer than that of the main rotating shaft 1A, and the lower stirring blade 6 of the sub-rotating shaft 1B is moved to the lower stirring shaft 3 of the main rotating shaft 1A. In contrast, when the injection is performed at the time of penetration , the sub-rotating shaft 1B is slightly shorter than the main rotating shaft 1A as shown in FIG. May be injected at the time of penetration as shown as a pattern 2 in Table 1 as a configuration positioned slightly above the lower stirring blade 3 of the main rotating shaft 1A .
Furthermore, about the lower stirring blades 3 and 6, either or both of the diameters may be slightly reduced so that the lower stirring blades 3 and 6 do not wrap each other. In this way, the height of the lower stirring blades 3 and 6 can be set to the same height position, which is preferable because the bottom position of the improved portion is aligned. However, even in this case, the height positions of the main injection port 4 and the sub injection port 9 need to be different within the range of the width of the lower stirring blades 3 and 6 in the vertical direction. The height position of the port 9 should be provided below the main injection port 4, and the height position of the sub injection port 9 should be provided above the main injection port 4 in the case of injection during penetration .
Further, in the above-described embodiment, the three-axis configuration includes the two main rotation shafts 1A on both sides and the central one-axis auxiliary rotation shaft 1B. However, the main rotation shaft 1A has at least two axes and at least one auxiliary rotation shaft. As long as the main rotational shaft 1A and the auxiliary rotational shaft 1B are alternately arranged in a state where the total number of shafts is an odd number of at least 3 or more and the main rotational shaft 1A is arranged on both sides, for example, 5 in FIG. As shown in the example in the case of a shaft configuration, it can be configured to have more axes.

In the present invention, the main rotary shaft 1A and the sub rotary shaft 1B can be independently controlled to rotate independently, and basically it is preferable to rotate them alternately in the opposite direction, but it is not limited thereto. The rotation direction and rotation speed of each rotary shaft 1 may be appropriately controlled. For example, it is realistic that the rotation direction is not always changed between the time of penetration and the time of extraction in order to promote the soil removal by the spiral 8, but when the amount of soil removed becomes excessive depending on the ground conditions, the spiral is used. 8 may be controlled so as to be temporarily reversely rotated or loosened, and conversely, when the amount of soil removal is insufficient, control may be performed so as to accelerate the rotation of the spiral.

1, showing an embodiment of the present invention, is a schematic configuration diagram showing a configuration example of a multi-axis composite stirring apparatus. It is a schematic process drawing of the multiaxial composite stirring method. It is a figure which shows an example of the shape of an improved body, and its example of arrangement | positioning. It is a figure which shows the other example of the arrangement | positioning of the shape of an improved body. It is a figure which shows the further another example of the shape of an improved body, and the example of arrangement | positioning. It is a schematic block diagram which shows the other structural example of a multiaxial composite stirring apparatus similarly. FIG. It is a schematic block diagram which shows the further another structural example of a multi-axis composite stirring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating shaft 1A Main rotating shaft 1B Sub rotating shaft 2 Connector 3,6 Lower stirring blade (stirring blade)
4 Main injection ports 5, 7 Upper stirring blade (stirring blade)
8 Spiral 9 Sub-injection port 10 Improved body 10a Mechanical stirring improvement unit 10b Main injection stirring improvement unit 10c Sub-injection stirring improvement unit 11 (11a, 11b) Discharge port 12 Rotation drive source

Claims (6)

In order to construct the improved body by performing mechanical stirring with a stirring blade while performing jetting stirring by spraying the improved material into the ground , the tip has at least three odd-numbered rotation shafts each equipped with a stirring blade. The rotating shafts are composed of at least two main rotating shafts and at least one sub rotating shaft, and the main rotating shafts and the sub rotating shafts are alternately arranged with the main rotating shafts arranged on both sides. The agitating blade provided at the tip of the main rotating shaft is provided with a main injection port for injecting the improved material into the ground, and the agitating blade provided at the tip of the auxiliary rotating shaft is provided with the main rotation. A sub-injection port for injecting the improved material at a pressure lower than the injection pressure from the main injection port provided on the shaft, and setting the position of the sub-injection port below the position of the main injection port, the shaft portion of the auxiliary rotary shaft, provided with a spiral to discharge soil pushing up the soil around Tajikufuku Upon performing ground improvement by using a stirring device,
While the mechanical stirring is performed by the stirring blades included in the main rotating shaft and the sub rotating shaft, while the soil is discharged by the spiral included in the sub rotating shaft, the improvement material is injected from the main injection port included in the main rotating shaft, and the sub rotating shaft is A multi-shaft composite stirring method in which an improved material is formed by injecting an improved material at a pressure lower than the injection pressure from the main injection port from the auxiliary injection port provided,
After the main rotary shaft and the sub rotary shaft have penetrated into the ground, when the main rotary shaft and the sub rotary shaft are pulled out from the ground, the sub rotary shafts are mechanically stirred by the stirring blades provided on the main rotary shaft and the sub rotary shaft, respectively. While discharging the soil by the spiral provided in the rotation shaft, the improvement material is injected from the main injection port provided in the main rotation shaft, and the sub injection port provided in the sub rotation shaft is improved at a pressure lower than the injection pressure from the main injection port. By jetting material to form an improved body,
The improved body is formed in a state where a mechanical agitation improving part integrally formed around the main rotating shaft and the sub rotating shaft and a mechanical agitating improving part formed around the main rotating shaft are expanded outward. In a shape having a jet agitating improvement part and a sub-injection stirring improvement part formed in the same diameter as the main injection agitation improvement part in a state where the mechanical agitation improvement part formed around the auxiliary rotating shaft is expanded outward A multi-shaft composite stirring method characterized by construction. The multi-shaft composite stirring method according to claim 1,
As the multi-shaft composite stirring device, the stirring blades included in the main rotating shaft and the sub rotating shaft are respectively composed of an upper stirring blade and a lower stirring blade, and the position of the lower stirring blade provided at the tip of the sub rotating shaft is the main. Set lower than the position of the lower stirring blade provided at the tip of the rotating shaft, provided a main injection port in the lower stirring blade provided at the tip of the main rotating shaft, and provided at the tip of the auxiliary rotating shaft A multi-shaft composite stirring method using a lower stirring blade provided with a sub-injection port. In order to construct the improved body by performing mechanical stirring with a stirring blade while performing jetting stirring by spraying the improved material into the ground , the tip has at least three odd-numbered rotation shafts each equipped with a stirring blade. The rotating shafts are composed of at least two main rotating shafts and at least one sub rotating shaft, and the main rotating shafts and the sub rotating shafts are alternately arranged with the main rotating shafts arranged on both sides. The agitating blade provided at the tip of the main rotating shaft is provided with a main injection port for injecting the improved material into the ground, and the agitating blade provided at the tip of the auxiliary rotating shaft is provided with the main rotation. A sub-injection port for injecting the improved material at a pressure lower than the injection pressure from the main injection port provided on the shaft, and setting the position of the sub-injection port above the position of the main injection port, the shaft portion of the auxiliary rotary shaft, provided with a spiral to discharge soil pushing up the soil around Tajikufuku Upon performing ground improvement by using a stirring device,
While the mechanical stirring is performed by the stirring blades included in the main rotating shaft and the sub rotating shaft, while the soil is discharged by the spiral included in the sub rotating shaft, the improvement material is injected from the main injection port included in the main rotating shaft, and the sub rotating shaft is A multi-shaft composite stirring method in which an improved material is formed by injecting an improved material at a pressure lower than the injection pressure from the main injection port from the auxiliary injection port provided,
While penetrating the main rotary shaft and the sub rotary shaft into the ground, the main rotary shaft while performing mechanical agitation with the stirring blades provided for the main rotary shaft and the sub rotary shaft respectively and discharging the soil with the spiral provided for the sub rotary shaft. The improvement material is injected from the main injection port provided in the sub rotation shaft, the improvement material is injected from the sub injection port provided in the sub rotation shaft at a pressure lower than the injection pressure from the main injection port, and then the main rotation shaft is formed. And by pulling out the sub rotating shaft from the ground,
The improved body is formed in a state in which a mechanical stirring improvement portion integrally formed around the main rotation shaft and the sub rotation shaft and a mechanical stirring improvement portion formed around the main rotation shaft are expanded outward. In a shape having a jet agitating improvement part and a sub-injection stirring improvement part formed in the same diameter as the main injection agitation improvement part in a state where the mechanical agitation improvement part formed around the auxiliary rotating shaft is expanded outward A multi-shaft composite stirring method characterized by construction. The multi-shaft composite stirring method according to claim 3,
As the multi-shaft composite stirring device, the stirring blades included in the main rotating shaft and the sub rotating shaft are respectively composed of an upper stirring blade and a lower stirring blade, and the position of the lower stirring blade provided at the tip of the sub rotating shaft is the main. Set above the position of the lower stirring blade provided at the tip of the rotating shaft, provided a main injection port in the lower stirring blade provided at the tip of the main rotating shaft, and provided at the tip of the auxiliary rotating shaft A multi-shaft composite stirring method using a lower stirring blade provided with a sub-injection port. The multiaxial composite stirring method according to any one of claims 1 to 4 ,
By controlling the rotation speed of the sub-rotation shaft independently of the main rotation shaft and controlling the amount of soil discharged by the spiral provided on the sub-rotation shaft, the auxiliary rotation shaft is integrally formed around the main rotation shaft and the sub-rotation shaft. A multi-shaft composite agitation method characterized by accelerating the flow of improved soil from the main rotating shaft side to the sub rotating shaft side in the mechanical stirring improving part. The multiaxial composite stirring method according to any one of claims 1 to 5 ,
By alternately rotating the main rotation shaft and the sub rotation shaft that are alternately arranged in the opposite directions, the improved soil is continuously formed in the mechanical stirring improvement portion integrally formed around the main rotation shaft and the sub rotation shaft. A multiaxial composite stirring method characterized by forming a series of flowing stirring streams.

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