JP4185449B2 - Excavation stirrer and ground improvement method - Google Patents

Description

  The present invention relates to an excavation stirring apparatus and a ground improvement method for excavating a excavation groove and stirring the excavation groove.

Conventionally, as a drilling and stirring device for excavating a drilling groove and stirring and mixing earth and sand and a solidifying agent in the drilling groove, a plurality of rotary shafts (excavation shafts) each provided with a drilling blade and a stirring blade, There is an excavation and agitation device that supports a multi-axis excavator body having a drive unit having a plurality of prime movers for rotating a rotation shaft on a leader mast of a base machine so as to be movable up and down. In this excavator agitation device, the multi-axis excavator body is lowered into the excavation groove while rotating the rotary shaft, thereby excavating and stirring in the excavation groove, and from the through hole provided in the rotary shaft into the excavation groove. An apparatus for injecting a solidifying agent (see, for example, Patent Document 1).
In addition, there is a drilling and stirring device configured to provide a rotating shaft provided with a stirring blade around the drive unit from above the drive unit, and to stir the inside of the excavation groove above the drive unit by this rotary shaft (for example, Patent Reference 2).

In addition, as shown in Japanese Patent Application No. 2002-204775, the applicant of the present invention has a peripheral drive type hydraulic motor (hereinafter referred to as an “outer motor”) having an output portion that can rotate around an inserted fixed shaft. ). In this excavating and agitating apparatus using an outer motor, a hollow shaft provided with an excavating blade and an agitating blade is provided so that a fixed shaft supported by a base machine passes through the outer motor and the fixed shaft is inserted. The shaft is connected to the output part of the outer motor, and the rotating shaft is rotated about the concentric shaft with the fixed shaft to perform excavation and stirring in the excavation groove, and the solidifying agent is removed from the through hole provided in the fixed shaft. It is configured to be injected into. Moreover, in order to stir the upper part in the excavation groove, an outer motor and a rotating shaft can be added to the upper part of the fixed shaft.
JP 2000-352070 A (page 1-4, FIG. 1-2) JP-A-10-219734 (page 1-4, FIG. 1-2)

However, the conventional excavation and stirring device has the following problems.
After the excavation and agitation of the excavation groove are completed, the excavation and agitation device is lifted from the excavation groove. At this time, the drive unit and the outer motor arranged below in the excavation groove are raised, and the resistance force generated between the outer wall surface of the drive unit and the outer motor and the excavation earth and sand is increased. Detachment work from the inside of the groove becomes complicated.
In addition, in the conventional excavation agitation device, in order to prevent the excavated earth and solidifying agent from hardening in the upper part of the excavation groove, an agitating blade is installed upward from the drive unit, or the upper part of the excavation groove. Correspondingly, a stirring blade is installed on the fixed shaft. However, when the depth of the excavation groove is large, a section in which the stirring blade is installed becomes large.

  Therefore, in the conventional excavation stirring apparatus, there is a problem that the operation of pulling up the multi-axis excavator body and the rotating means from the excavation groove becomes complicated due to the resistance force generated in the drive unit or the outer motor. In addition, in the configuration in which the stirring blades are installed corresponding to the upper part of the excavation groove, the section in which the stirring blades are installed may become large, which increases the weight of the excavation stirring device and the cost of manufacturing the device. There is a problem that becomes high.

  The present invention has been made to solve the above problems, and can be easily pulled up from the excavation groove without installing a stirring blade corresponding to the total height in the excavation groove, thereby improving the construction efficiency. An object of the present invention is to provide an excavating and stirring device and a ground improvement method capable of performing the above.

  The present invention is configured to solve the above problems, and the invention according to claim 1 includes a base machine and a plurality of rotating means supported by the base machine so as to be movable up and down. The means is arranged in parallel to the base machine, and each rotating means has a drilling blade and a stirring blade, and excavates the excavation groove with the excavation blade and also excavates the stirring groove with the stirring blade. Each rotating means is connected to a fixed shaft, a hydraulic motor in which the fixed shaft is inserted, and an output portion provided with a stirring blade around the fixed shaft and the output portion of the hydraulic motor. The rotary shaft is rotatable about a concentric shaft with the fixed shaft, and has a drilling blade at the lower portion and a rotary shaft with a stirring blade around it. At least one rotating means is drilled at the upper portion of the rotary shaft. It is characterized by having a blade .

Here, the configuration of the base machine is not limited to a self-propelled type or a fixed type as long as it is a device capable of moving the rotating means up and down.
The hydraulic motor is an existing hydraulic motor such as a radial piston motor or an axial piston motor.
Further, the shapes and configurations of the rotary shaft excavating blade and the agitating blade are not limited, and the shape and configuration can efficiently excavate the excavation groove and reliably agitate the inside of the excavation groove. That's fine.

According to this invention, the agitating blade is provided around the output portion of the hydraulic motor, and the output portion can rotate around the fixed shaft. Therefore, when the rotating means is pulled up from the excavation groove, the output portion is fixed. By raising the hydraulic motor while rotating around the shaft, the resistance force between the hydraulic motor and excavated earth and sand can be reduced, and the rotating means can be easily pulled up from the excavation groove.
In addition, a drilling blade is installed at the top of the rotating shaft, and when the rotating means is pulled up from the drilling groove, even if the hardened excavated sediment and solidifying agent are progressing above the drilling groove, the drilling is performed. Since the excavated earth and sand can be crushed and softened by the blade, the rotating means can be easily pulled up from the excavation groove without installing a stirring blade corresponding to the total height in the excavation groove.
Furthermore, since the inside of the excavation groove is agitated by the agitating blade provided around the output portion of the hydraulic motor together with the agitating blade provided on the rotating shaft, the inside of the excavation groove can be efficiently stirred.
Further, by providing the stirring blades around the output portion of the hydraulic motor, the stirring blades are installed over a wide range in the height direction of the rotating means, so that the excavated sediment can be efficiently discharged upward.

In addition, since the rotation shaft is directly connected to the output part of the hydraulic motor without installing a drive mechanism such as a gear mechanism, the rotating means is reduced in weight and there is no need to provide a counterweight or the like in the base machine. In addition, the configuration of the excavating and agitating device can be simplified, and the production cost can be reduced.
In addition, since the fixed shaft does not rotate during excavation, it is not necessary to install a special mechanism such as a swivel joint when a solidifying agent supply pipe is connected to the fixed shaft, and the configuration of the rotating means can be simplified. . Furthermore, by extending the fixed shaft to the lower part of the excavation groove and easily installing various measuring devices on the fixed shaft that does not rotate, it is possible to grasp the excavation state in the excavation groove in real time and accurately manage the construction. be able to.

  The invention according to claim 2 is an invention related to the excavation and agitation device according to claim 1, and includes a base machine and three rotating means supported by the base machine so as to be movable up and down. Each rotating means is arranged in parallel to the base machine, and each rotating means has a drilling blade and a stirring blade, and excavates the excavating groove with the excavating blade, and agitates the inside of the excavating groove with the stirring blade. In the three rotation means, the rotation means arranged at the center is rotatable by being inserted into the first hydraulic motor and the output portion of the first hydraulic motor, and has a drilling blade at the lower part. The three rotating means, each of the rotating means arranged at both ends, have a fixed shaft and a fixed shaft interpolated around the stirring blade. The output section prepared for the By connecting to the second hydraulic motor capable and the output part of the second hydraulic motor, it can rotate around the fixed shaft and the concentric shaft, and has a drilling blade at the bottom and rotation with a stirring blade around And at least one rotating means includes an excavating blade on an upper portion of the rotating shaft.

  According to the present invention, the first hydraulic motor that rotates the rotating shaft that is inserted into the output portion can be made smaller than the second hydraulic motor that rotates the output portion around the fixed shaft that is inserted. Therefore, the space between the rotating means arranged at both ends can be reduced. Moreover, since the first hydraulic motor is less expensive to manufacture than the second hydraulic motor, the manufacturing cost of the excavating and stirring device can be reduced.

  The invention according to claim 3 is an invention related to the excavating and agitating device according to claim 1 and claim 2, wherein the base machine and three rotating means supported by the base machine so as to be movable up and down are provided. Each rotating means is arranged in parallel with the base machine, each rotating means has a drilling blade and a stirring blade, and excavates the drilling groove with the drilling blade, and the inside of the drilling groove with the stirring blade. An excavating and stirring apparatus for stirring, in the three rotating means, the rotating means arranged in the center is rotatable by being inserted into the first hydraulic motor and the output portion of the first hydraulic motor, In the three rotating means, each rotating means arranged at both ends includes a fixed shaft, and the fixed shaft is inserted in the three rotating means. Output with a stirring blade around Is connected to the output portion of the second hydraulic motor and the second hydraulic motor that can rotate about the fixed shaft, and can rotate about the fixed shaft and the concentric shaft. A shaft, a third hydraulic motor supported by the fixed shaft, and a third hydraulic motor which is rotatable by being inserted into the output portion of the third hydraulic motor, and which has a drilling blade at the bottom and a stirring blade around The rotating shaft includes at least one rotating means including an excavating blade above the rotating shaft.

  Here, the second hydraulic motor in which the output portion rotates around the inserted fixed shaft has a large diameter of the rotating output portion. Therefore, when excavating the viscous soil, there is much adhesion of excavated soil to the output portion. It may become. On the other hand, in the 3rd hydraulic motor which rotates the rotating shaft inserted in the output part, since the diameter of a rotating shaft can be made small, adhesion of excavated earth and sand can be decreased. That is, when the clay is agitated by the second hydraulic motor, a torque larger than that of the third hydraulic motor may be required.

  According to this invention, the rotating means arranged at both ends include the third hydraulic motor suitable for stirring the clay, and above the third hydraulic motor, the rotating means is provided upward by the stirring blade provided in the output unit. Since the 2nd hydraulic motor with high soil removal efficiency is installed, various soil grounds can be constructed efficiently.

The invention according to claim 4 is the excavation and agitation device according to any one of claims 1 to 3, wherein at least one rotating means has a lower end portion of the rotating means around a horizontal axis. It is characterized by being tiltable .

According to this invention, the lower end of the rotating means whose axial direction is arranged in the vertical direction is tilted around the horizontal axis in the excavation groove, and the excavating blade and the stirring blade of the rotating means are moved obliquely upward. Since the side wall of the excavation groove can be excavated at a desired depth, the excavation groove can be easily widened.

The configuration for tilting the lower end portion of the rotating means around the horizontal axis is not limited. For example, the fixed shaft of the rotating means is divided into an upper part and a lower part, and the upper part and the lower part of the fixed shaft are separated via a horizontal shaft member. There is a configuration in which the upper and lower ends of the hydraulic cylinder are respectively attached to the upper and lower portions of the fixed shaft. In this configuration, by expanding or contracting the hydraulic cylinder is tilted at the bottom of the fixed shaft, by refracting the rotation means, it is possible to tilt the lower end of the rotating means. At this time, in the rotating means having a hydraulic motor that can rotate around the fixed shaft, the rotating member does not exist at the refracted portion by providing a refracted portion on the fixed shaft above the rotating shaft and the hydraulic motor. It is possible to simplify the configuration of the refracting rotating means without providing a complicated mechanism such as a universal joint at the refracting portion.
Further, the lower end portion of the rotating means may be tilted around the horizontal axis by providing a rotation center at the support portion of the rotating means and tilting the entire rotating means.

  The invention according to claim 5 is a ground improvement method, wherein (1) the base machine of the excavating and agitating device according to any one of claims 1 to 4 at a side of a predetermined position for excavation. The first step of abutting the excavating blade installed on the rotating shaft against the ground surface by moving each rotating means and (2) rotating the rotating shaft of each rotating means, A second step of constructing excavation grooves of a predetermined depth by sequentially lowering each rotation means by a base machine and disposing a hydraulic motor of each rotation means in the excavation groove, and (3) rotation means The third step of injecting the solidifying agent into the excavation groove while excavating the ground with, and stirring and mixing the excavated sediment and solidifying agent with the stirring blade, and (4) each rotation while stirring and mixing the excavated sediment and the solidifying agent Raise the means and pull it up from the excavation groove to harden the excavated sediment in the excavation groove It is characterized in that it comprises a fourth step of.

  According to the present invention, when each rotating means is raised and pulled up from the excavation groove, the excavation stirring device of the present invention can reduce the resistance force of the hydraulic motor and the excavation earth and sand, and excavate above the excavation groove. Since the earth and sand can be pulverized, each rotating means can be easily pulled up from the excavation groove.

According to the excavation agitation apparatus and the ground improvement method of the present invention, the agitating blade is provided around the output part of the hydraulic motor, and the output part can rotate around the fixed shaft. At this time, the resistance force between the hydraulic motor and the excavated soil can be reduced by raising the hydraulic motor while rotating the output portion. Furthermore, even when the excavating blade is installed on the upper part of the rotating shaft and the hardening of the excavating soil and solidifying agent is progressing above the excavation groove, the excavating blade is crushed and softened. Therefore, the rotating means can be easily pulled up from the excavation groove without installing a stirring blade corresponding to the total height in the excavation groove, and the construction efficiency can be increased.
Further, since the inside of the excavation groove is agitated by the agitating blade provided around the output portion of the hydraulic motor together with the agitating blade provided on the rotating shaft, the inside of the excavation groove can be efficiently stirred.
Furthermore, by providing the stirring blades around the output part of the hydraulic motor, the stirring blades are installed over a wide range in the height direction of the rotating means, so that the excavated sediment can be efficiently discharged upward.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
In the description of each embodiment, the same constituent elements are denoted by the same reference numerals, and redundant descriptions are omitted.

  In this embodiment, the excavation and stirring device of the present invention is used to excavate a vertical excavation groove, a solidifying agent is injected into the excavation groove, and the ground is improved by stirring and mixing the excavated sediment and the solidifying agent. An example of the case of curing by heating will be described.

[First Embodiment]
First, the excavation and stirring apparatus according to the first embodiment of the present invention will be described.
FIG. 1 is a side view showing an excavation and agitation device according to a first embodiment of the present invention. FIG. 2 is a front view showing the rotating means according to the first embodiment of the present invention. 3A and 3B are diagrams showing a fixed shaft of the rotating means according to the first embodiment of the present invention, in which FIG. 3A is a cross-sectional view taken along the line AA in FIG. 2, and FIG. (C) is CC sectional drawing of FIG. In the following description, the right side is the right side in FIG. 2, and the left side is the left side in FIG.

First, the structure of the excavation stirring apparatus which concerns on embodiment of this invention is demonstrated.
As shown in FIGS. 1 and 2, the excavating and stirring apparatus 1 includes a base machine 2 and three rotating means 20C, 20R, and 20L supported by the base machine 2 so as to be movable up and down. , 20R, 20L are juxtaposed to the base machine 2, and each rotating means 20C, 20R, 20L has a drilling blade 22 and a stirring blade 23, and excavates a drilling groove with the drilling blade 22, and excavates. A solidifying agent is injected into the groove, and the ground is improved by stirring and mixing the excavated sediment and the solidifying agent by the stirring blade 23.

Next, the configuration of the base machine 2 will be described.
As shown in FIG. 1, the base machine 2 includes a vertical lifting rail 3, a support member 4 that can be lifted and lowered along the lifting rail 3, a swivel base 5 for swiveling the lifting rail 3 in the horizontal direction, Driven from the tilting means 6 for rotating the elevating rail 3 in the vertical direction, the oil supply pipe 7 for supplying driving oil to the rotating means 20C, 20R, 20L, and the rotating means 20C, 20R, 20L. The oil drain pipe 8 for discharging the oil, the supply pipe 9 for supplying the solidifying agent to the rotating means 20C, 20R, and 20L, and the caterpillar 10 for moving the base machine 2 are configured as main parts. ing.

The turning pedestal 5 is composed of an upper pedestal 5a and a lower pedestal 5b, and an elevating rail 3 is connected to the upper pedestal 5a. By rotating the upper pedestal 5a in the horizontal direction, the elevating rail 3 is moved in the horizontal direction. Can be swiveled.
The retractable means 6 of the elevating rail 3 is an extendable hydraulic cylinder. The lower end is connected to the upper pedestal 5 a and the upper end is connected to the upper end of the elevating rail 3. By extending and contracting, the elevating rail 3 can be rotated in the vertical direction around the rotation support portion 11 provided at the lower end of the elevating rail 3.

  The support member 4 is a member that supports each of the rotating means 20C, 20R, and 20L in a state in which the rotation means 20C can be lifted and lowered in the vertical direction along the lift rail 3. The mechanism for raising and lowering the support member 4 is not limited. In this embodiment, an electric winch (not shown) is installed on the swivel base 5 and the wire 12 of this electric winch is connected to the elevating rail 3. The support member 4 is lifted by being fixed to the upper end portion of the elevating rail 3 via a pulley 13 installed at the upper end of the rail and a pulley 14 installed at the upper portion of the support member 4, and the wire 12 is fed or wound up. The support member 4 is raised and lowered.

  The oil supply pipe 7 and the oil discharge pipe 8 are members provided for driving the respective rotation means 20C, 20R, and 20L, and each rotation means 20C, from an oil tank (not shown) installed at a construction site. It is connected to 20R and 20L. Then, driving oil is supplied from the oil tank to the rotating means 20C, 20R, and 20L through the oil supply pipe 7, and the driving oil discharged from the rotating means 20C, 20R, and 20L is collected in the oil tank through the oil discharging pipe 8. It is configured to be. The supply pipe 9 is connected to each rotating means 20R, 20L from a storage tank (not shown) installed at the construction site, and the solidifying agent in the storage tank passes through the supply pipe 9 to each rotating means 20R, 20R, 20L, 20L. It is configured to be supplied to 20L.

Next, the configuration of the rotating means 20C, 20R, 20L will be described.
As shown in FIGS. 1 and 2, the excavating and stirring apparatus 1 includes three rotating means 20C, 20R, and 20L arranged in parallel to the base machine 2, and a central rotating means 20C disposed in the center. The right rotation means 20R arranged on the right side and the left rotation means 20L arranged on the left side. The rotating means 20C, 20R, and 20L are integrated in a state where they are juxtaposed by a connecting member 24 and a bearing member 25, and are supported by the base machine 2 so as to be movable up and down.

  As shown in FIG. 2, the central rotating means 20C is a member arranged at the center of the three rotating means 20C, 20R, and 20L arranged side by side. The central rotating means 20C has a fixed shaft 30C having an upper end fixed to the connecting member 24, and a fixed shaft 30C passing therethrough, and an output portion having a stirring blade 23 around can rotate around the fixed shaft 30C. The hydraulic motor (hereinafter referred to as “outer motor”) 40C and the fixed shaft 30C are inserted into the output portion of the outer motor 40C so as to be inserted therein, and can rotate around the fixed shaft 30C. The rotary shaft 21 </ b> C is provided with a drilling blade 22 at the lower end and a stirring blade 23 around it.

  The outer motor 40C of the central rotating means 20C is an outer peripheral drive type radial piston motor whose output portion rotates around the fixed shaft 30C that penetrates. In the first embodiment, the outer motor 40C is substantially at the center in the height direction of the fixed shaft 30C. Is provided. And the stirring blade 23 formed helically along the outer peripheral surface of an output part is attached.

As shown in FIG. 3, the fixed shaft 30C of the central rotating means 20C is a hollow tube having a through hole 31 in the central portion. Around the through hole 31 in the central portion, compressed air is introduced into the excavation groove. An air hole A for supplying, an oil supply hole B for supplying driving oil to the outer motor 40C (see FIG. 2), an oil discharge hole C for discharging driving oil from the outer motor 40C, Eight through holes including a drain hole D when the driving oil flows out inside the outer motor 40C and four spare holes E are arranged at equal intervals.
The oil supply hole B, the oil discharge hole C, and the drain hole D are connected to the outer motor 40C. In each of the holes B, C, and D, a section that is not used below the connection portion with the outer motor 40C is a spare. Hole E.

  As shown in FIG. 2, the rotating shaft 21C of the central rotating means 20C is a hollow tube provided with a stirring blade 23 formed in a spiral shape along the outer peripheral surface, and is divided up and down via an outer motor 40C. The upper rotary shaft 21Ca provided with the excavating blade 22 at the upper portion and the lower rotary shaft 21Cb provided with the excavating blade 22 at the lower end portion are formed so as to interpolate the fixed shaft 30C. And the lower end part of upper rotating shaft 21Ca and the upper end part of lower rotating shaft 21Cb are connected to the output part of the outer motor 40C, and can rotate around the fixed shaft 30C. The lower rotary shaft 21Cb penetrates the bearing member 25 in a rotatable state.

Then, by rotating the upper rotary shaft 21Ca and the lower rotary shaft 21Cb by the outer motor 40C, the excavating blade 22 of the lower rotary shaft 21Cb can be rotated to excavate the earth and sand in the excavation groove, and the upper rotary shaft 21Ca The excavating blade 22 can be rotated to crush the excavated earth and sand stored above the upper rotary shaft 21Ca, and the agitating blade 23 can be further rotated to agitate and mix the excavated earth and solidification agent in the excavated groove. be able to.
In addition, the structure of the digging blade 22 and the stirring blade 23 should just be a shape and material which can perform digging and stirring efficiently, and is not specifically limited.

  As shown in FIGS. 1 and 2, the right rotation means 20R is a member arranged on the right side of the three rotation means 20C, 20R, and 20L arranged side by side. The right rotating means 20R has a fixed shaft 30R whose upper end is fixed to the support member 4 of the base machine 2 and a fixed shaft 30R that penetrates, and an output portion provided with a stirring blade 23 around the fixed shaft 30R. The two outer motors 40Ra and 40Rb that can be rotated to each other and the fixed shaft 30R are inserted into the outer motors 40Ra and 40Rb so that they can be rotated around the fixed shaft 30R. The rotary shaft 21 </ b> R includes the excavating blade 22 at the upper and lower ends and a stirring blade 23 around the rotary blade 21 </ b> R.

The outer motors 40Ra and 40Rb of the right rotating means 20R are outer peripheral drive type radial piston motors whose output portions rotate around the fixed shaft 30R that penetrates, and are installed at a predetermined interval in the height direction of the fixed shaft 30R. A stirring blade 23 formed in a spiral shape is attached along the outer peripheral surface of the output portion. An outer motor (hereinafter referred to as “upper outer motor”) 40Ra disposed above is disposed above the outer motor 40C of the central rotating means 20C, and an outer motor (hereinafter referred to as “lower outer motor”) disposed below. 40Rb (referred to as “motor”) is disposed below the outer motor 40C of the central rotating means 20C.
In the present embodiment, the upper outer motor 40Ra and the lower outer motor 40Rb are rotated in different directions. Further, the lower outer motor 40Rb of the right rotating means 20R and the outer motor 40C of the central rotating means 20C are rotated in different directions.

As shown in FIG. 2, the fixed shaft 30 </ b> R of the right rotation means 20 </ b> R penetrates the connection member 24 and is fixed at the upper end to the support member 4 of the base machine 2, and the central rotation means 20 </ b> C via the connection member 24. And integrated.
2 and 3, the fixed shaft 30R is a hollow tube having a through hole 31 in the central portion. The through hole 31 in the central portion extends from the lower end of the fixed shaft 30R into the excavation groove. It is a supply hole for supplying a solidifying agent to the. Further, around the through hole 31, there are an air hole A for supplying compressed air from an air supply means (not shown) to an air hole A of the central rotating means 20C, and an oil supply hole B of the central rotating means 20C. Oil supply hole B for supplying drive oil, oil supply hole F for supplying drive oil to the upper outer motor 40Ra, oil supply hole G for supplying drive oil to the lower outer motor 40Rb, Oil drain hole H for discharging drive oil from outer motor 40Ra, oil drain hole I for discharging drive oil from lower outer motor 40Rb, and drive oil inside outer motors 40Ra and 40Rb Eight through-holes consisting of a drain hole D and a preliminary hole E when the gas flows out are arranged at equal intervals.

  Further, the air hole A and the oil supply hole B of the right rotation means 20R are connected and communicated with the air hole A and the oil supply hole B of the central rotation means 20C by a hose or the like (not shown) in the connection member 24. Further, the oil supply holes F and G, the oil discharge holes H and I, and the drain hole D of the right rotation means 20R are connected to the outer motors 40Ra and 40Rb, respectively, and the drain hole D is a central rotation means in the connection member 24. The 20C drain hole D is connected to and communicated with a hose or the like (not shown). In each of the holes B, F, G, H, I, and D, a section that is not used below the connecting portion with various members is a preliminary hole E.

Here, in the connection between each hole A, B, D of the right rotation means 20R in the connection member 24 and each hole A, B, D of the central rotation means 20C, the fixed shafts 30C, 30R do not rotate. There is no need to install a special mechanism such as a swivel joint.
The supply pipe 9 is connected to the through hole 31 of the right rotation means 20R, the oil supply pipe 7 is connected to the oil supply holes F and G, and the oil discharge pipe 8 is connected to the oil discharge holes H and I. A drain pipe (not shown) is connected to the drain hole D (see FIG. 1). Note that the fixed shaft 30R does not rotate when connecting the holes 31, F, G, H, I, and D to the pipes 7, 8, and 9. Therefore, it is necessary to install a special mechanism such as a swivel joint at the connection portion. There is no.

  As shown in FIG. 2, the rotation shaft 21R of the right rotation means 20R is a hollow tube provided with a stirring blade 23 formed in a spiral shape along the outer peripheral surface, and is vertically moved via outer motors 40Ra and 40Rb. It is divided into three. Further, the excavating blade 22 is provided at the top, the upper rotating shaft 21Ra disposed above the outer motor 40Ra, the middle rotating shaft 21Rb disposed below the outer motor 40Ra, and the excavating blade 22 at the lower end. The lower rotary shaft 21Rc disposed below the outer motor 40Rb is formed so as to interpolate the fixed shaft 30C. The lower end portion of the upper rotary shaft 21Ra and the upper end portion of the middle rotary shaft 21Rb are connected to the output portion of the outer motor 40Ra, and the upper end portion of the lower rotary shaft 21Rc is connected to the output portion of the outer motor 40Rb. Thus, the rotating shaft 21R can rotate around the fixed shaft 30C. Further, the lower rotary shaft 21Rc passes through the bearing member 25 in a rotatable state, and is integrated with the central rotating means 20C via the bearing member 25.

  And by rotating each rotating shaft 21Ra, 21Rb, 21Rc by the outer motors 40Ra, 40Rb, the excavating blade 22 of the lower rotating shaft 21Rc can be rotated to excavate the bottom surface of the excavation groove, and the upper rotating shaft 21Ra. The excavating blade 22 can be rotated to pulverize the excavated earth and sand stored above the upper rotary shaft 21Ra, and the agitating blade 23 can be rotated to agitate and mix the excavated earth and solidification agent in the excavated groove. can do.

  As shown in FIGS. 1 and 2, the left rotation means 20L is a member arranged on the left side of the three rotation means 20C, 20R, and 20L arranged side by side. The left rotation means 20L has a fixed shaft 30L whose upper end is fixed to the support member 4 of the base machine 2, and a fixed shaft 30L passing therethrough, and an output portion provided with a stirring blade 23 around the fixed shaft 30L. Two outer motors 40La, 40Lb that can rotate around and the fixed shaft 30L are inserted into the outer motors 40La, 40Lb so that they can be rotated around the fixed shaft 30L. The upper and lower end portions are provided with excavating blades 22 and a rotating shaft 21L provided with a stirring blade 23 around. The left rotation means 20L has substantially the same configuration as the right rotation means 20R, and the configuration of the through holes provided in the fixed shaft 30L is different.

  As shown in FIGS. 2 and 3, the fixed shaft 30L of the left rotating means 20L is provided with driving oil from the outer motor 40C of the central rotating means 20C around the central through hole 31 that is a supply hole for the solidifying agent. Oil discharge hole C for discharging the oil, oil supply holes F and G for supplying the drive oil to the outer motors 40La and 40Lb, and a discharge oil for discharging the drive oil from the outer motors 40La and 40Lb. Eight through holes including oil holes H and I, drain holes D of the outer motors 40La and 40Lb, and two preliminary holes E are arranged at equal intervals. The oil drain hole C of the left rotating means 20L is connected to and communicated with the oil drain hole C of the central rotating means 20C by a hose or the like (not shown) in the connecting member 24.

Next, the ground improvement method using the excavation stirring apparatus 1 which concerns on 1st Embodiment of this invention is demonstrated.
First, as shown in FIG. 1 and FIG. 2, the base machine 2 is moved to the side of a predetermined position to be excavated, the swivel base 5 and the tilting means 6 are adjusted, and each rotating means 20 is set to a predetermined position in a vertical state. Install. And each rotation means 20C, 20R, 20L is lowered | hung, and the excavation blade 22 installed in the lower end part of each rotating shaft 21C, 21R, 21L is made to contact | abut to a ground surface.

  Subsequently, the outer motors 40C, 40R, 40L of the rotating means 20C, 20R, 20L are driven to rotate the rotating shafts 21C, 21R, 21L, and the base is excavated by the excavating blade 22 at the lower end. The rotating means 20C, 20R, and 20L are sequentially lowered by the machine 2 to construct excavation grooves having a predetermined depth, and the outer motors 40C, 40R, and 40L of the rotating means 20C, 20R, and 20L are arranged in the excavation grooves. To do. At this time, the two outer motors 40R and 40L respectively installed in the right side rotating means 20R and the left side rotating means 20L rotate in different directions, and the rotational reaction force cancels each other. 21L rotates in a stable state.

  Further, the positions of the three rotation means 20C, 20R, and 20L can be adjusted by setting the start / stop and rotation directions of the respective rotation shafts 21C, 21R, and 21L. For example, by rotating only the rotating shaft 21C of the central rotating means 20C and rotating the entire three rotating means 20C, 20R, 20L around the central rotating means 20C, the positions of the rotating means 20C, 20R, 20L are determined. Can be fine-tuned.

  On the other hand, the solidifying agent is supplied to the through holes 31 of the right rotating means 20R and the left rotating means 20L through the supply pipe 9 (see FIG. 3) while excavating the ground with the rotating means 20C, 20R, 20L. This solidifying agent is injected into the excavation groove from the lower end of the through hole 31 at the center of the right rotation means 20R and the left rotation means 20L. Further, compressed air is supplied into the excavation groove from the air hole A of the central rotating means 20C.

  The excavated sediment and the solidifying agent are stirred and mixed by the stirring blades 23 of the rotating means 20C, 20R, and 20L. At this time, since the inside of the excavation groove is also agitated by the agitating blades 23 of the outer motors 40C, 40R, and 40L together with the agitating blades 23 of the rotary shafts 21C, 21R, and 21L, the excavated sediment and the solidifying agent are efficiently agitated and mixed. can do. Further, since the rotation shaft 21C of the central rotation means 20C and the rotation shafts 21R and 21L of the right-side rotation means 20R and the left-side rotation means 20L rotate in different directions, there is no doubt between the rotation shafts 21C, 21R, and 21L. Is mixed with stirring. Further, since the stirring blades 23 of the outer motors 40C, 40R, and 40L are installed in a wide range in the height direction of the rotating means 20C, 20R, and 20L, the excavated soil is efficiently discharged upward. can do.

  Finally, the rotating means 20C, 20R, and 20L are raised and pulled up from the excavation groove while mixing the excavated earth and the solidifying agent with stirring. At this time, since the resistance force between the outer motors 40C, 40R, 40L and the excavated earth and sand is reduced by rotating the output part of each outer motor 40C, 40R, 40L provided with the stirring blade 23 while rotating, It can be easily pulled up from the excavation groove. Further, even when the hardening of the excavated soil has progressed above the excavation groove, the excavated earth and sand are crushed and softened by the excavating blades 22 installed at the upper portions of the rotary shafts 21C, 21R, and 21L. Therefore, it can be easily pulled up from the excavation groove. Then, after the rotation means 20C, 20R, and 20L are detached, hardening of the excavated earth and sand in the excavation groove is completed and the ground is improved.

  Therefore, in the excavation agitation apparatus 1 of the present invention, when each rotating means 20 is detached from the excavation groove, it can be easily pulled up, and the agitation blades 23 provided around the outer motor 40 are efficiently agitated. Therefore, construction efficiency can be increased.

[Second Embodiment]
Next, an excavation stirring apparatus according to the second embodiment of the present invention will be described.
4A and 4B are views showing a rotating means according to a second embodiment of the present invention, wherein FIG. 4A is a front view of the rotating means, and FIG. 4B is a view showing another configuration of the rotating means, and a right-side rotating means. It is the front view which showed the structure which provided one outer motor in the left side rotation means. FIG. 5 is a view showing another configuration of the rotating means according to the second embodiment of the present invention, and is a front view showing a configuration in which the inner motor of the central rotating means is provided in the central portion in the height direction. FIG. 6 is a view showing another configuration of the rotating means according to the second embodiment of the present invention, and is a front view showing a structure in which the upper excavating blade is not provided in the right rotating means and the left rotating means. .

As shown in FIG. 4A, the excavation agitation apparatus according to the second embodiment of the present invention has substantially the same configuration as the excavation agitation apparatus according to the first embodiment, and the configuration of the central rotating means 20C is different. Yes.
The central rotating means 20C of the excavating and agitating apparatus according to the second embodiment has a hydraulic motor integrated with the right rotating means 20R and the left rotating means 20L (hereinafter referred to as the outer peripheral wall). , Which is connected to the output portion in a state of passing through the output portion of the inner motor 50, and provided with the excavating blade 22 at the upper and lower end portions, and the rotation provided with the stirring blade 23 around It is comprised from the axis | shaft 21C. Here, since the inner motor 50 can be formed smaller than the outer motors 40R and 40L, the interval between the right rotation means 20R and the left rotation means 20L can be reduced. Further, since the inner motor 50 is less expensive to manufacture than the outer motors 40R and 40L, the manufacturing cost of the excavating and stirring device can be reduced.

  Moreover, each rotating means 20C, 20R, 20L shown in FIG. 4B is another configuration of the excavating and stirring device using the central rotating means 20C provided with the inner motor 50, and the outer motors 40R, 40L. By changing the number, the lengths of the right rotation means 20R and the left rotation means 20L are shortened. In this configuration, each of the fixed shafts 30R, 30L is provided with one outer motor 40R, 40L, and the output portion of the one outer motor 40R, 40L is connected to the lower ends of the upper rotary shafts 21Ra, 21La and The upper ends of the lower rotary shafts 21Rc and 21Lc are connected.

  The arrangement of the outer motors 40R, 40L and the inner motor 50 is not limited. As shown in FIG. 5, the connecting member 24 to which the inner motor 50 of the central rotating means 20C is fixed is connected to the right rotating means 20R. Also, it may be provided between the upper outer motors 40Ra, 40La and the lower outer motors 40Rb, 40Lb provided on the left rotation means 20L, and is set appropriately according to the configuration of the stirring blade 23 and the strength of each member. It is preferable to do. In this configuration, bearing members 25, 25 are provided above the upper outer motors 40Ra, 40La and below the lower outer motors 40Rb, 40Lb to integrate the rotating means 20C, 20R, 20L.

  Further, as shown in FIG. 6, the excavating blade 22 for pulverizing the excavated earth and sand stored in the excavation groove above the rotating means 20C, 20R, and 20L is connected to the right rotating means 20R and the left rotating means 20L. By providing the excavating blade 22 only on the upper part of the rotating shaft 21C of the central rotating means 20C without providing it on the rotating shafts 21R and 21L, the configuration of the excavating and stirring device can be simplified. Thus, it is preferable to appropriately set the shape and arrangement of the excavation blade 22 and the stirring blade 23 in accordance with the soil quality of the ground to be excavated.

[Third Embodiment]
Next, an excavation and stirring device according to a third embodiment of the present invention will be described.
FIG. 7 is a view showing a rotating means according to a third embodiment of the present invention, and is a front view showing a configuration in which an outer motor and an inner motor are provided on the right rotating means and the left rotating means.
The excavation and agitation device according to the third embodiment of the present invention has substantially the same configuration as that of the excavation and agitation device according to the second embodiment. As shown in FIG. 7, the configuration of the right side rotation means 20R and the left side rotation means 20L is the same. Is different.

  The right rotation means 20R and the left rotation means 20L according to the third embodiment have fixed shafts 30R, 30L and fixed shafts 30R, 30L penetrating through them, and an output portion provided with a stirring blade 23 around the fixed shaft 30R, The outer motors 40R and 40L that can rotate around 30L and the fixed shafts 30R and 30L are inserted into the outer motors 40R and 40L so that they can be rotated around the fixed shafts 30R and 30L. The upper rotary shafts 21Ra and 21La having the excavating blade 22 at the top and the stirring blades 23 around, the inner motors 50R and 50L fixed to the lower ends of the fixed shafts 30R and 30L, and the upper end Can be rotated by being inserted into the output part of the inner motors 50R, 50L, the excavating blade 22 is provided at the lower end part, and the stirring blade 23 is Lower rotary shaft 21Rb provided in, and a 21Lb.

  Here, since the outer motors 40R and 40L have a large diameter of the rotating output part, when the ground to be excavated is a clay soil, the adhesion of the excavated soil to the output part may increase. Therefore, by installing the inner motors 50R and 50L to which the lower rotary shafts 21Rb and 21Lb are connected below the outer motors 40R and 40L, the inner motors 50R and 50L are provided on the lower rotary shafts 21Rb and 21Lb with a small diameter and less adhesion of excavated soil. Since the excavating blade 22 can excavate the viscous soil efficiently and the upper outer motors 40R, 40L can efficiently excavate the soil, various soils can be efficiently constructed.

[Fourth Embodiment]
Next, an excavation and stirring apparatus according to a fourth embodiment of the present invention will be described.
FIGS. 8A and 8B are views showing a rotating means according to the fourth embodiment of the present invention, wherein FIG. 8A is a front view showing a configuration in which the central rotating means can be tilted, and FIG. 8B is a tilting of the central rotating means. It is DD sectional drawing of Fig.8 (a) in a state.
The excavation agitation apparatus according to the fourth embodiment of the present invention has substantially the same configuration as the excavation agitation apparatus according to the second embodiment shown in FIG. 6, and the configuration of the central rotating means 20C is different as shown in FIG. ing.

In the central rotating means 20 </ b> C according to the fourth embodiment, horizontal shaft members 24 a and 24 a attached to the left and right sides of the inner motor 50 are supported by the connecting member 24 in a rotatable state. Therefore, by rotating the inner motor 50 about the concentric axis with the horizontal shaft members 24a, 24a, the lower end portion of the central rotating means 20C is tilted about the horizontal axis toward the upper right in FIG. 8B. Thus, the entire central rotating means 20C can be tilted with the horizontal shaft members 24a, 24a as the support shafts.
Reference numeral 24c denotes a hydraulic cylinder for rotating the inner motor 50. The axial direction is arranged in the vertical direction, the main body is attached to the bearing member 25 above the connecting member 24, and the rod The part is attached to the upper part of the inner motor 50. Accordingly, the inner motor 50 can be rotated about the horizontal shaft member 24a as a support shaft by expanding and contracting the two hydraulic cylinders 24b and 24b.
Further, in the central rotating means 20 </ b> C according to the fourth embodiment, two rotating shafts 21 </ b> C and 21 </ b> C are arranged in parallel with respect to one inner motor 50, and a gear attached to the output portion of the inner motor 50. The two rotary shafts 21C and 21C can be rotated by the mechanism 24b.

Thus, by enabling the central rotating means 20C to tilt, the central rotating means 20C is tilted in the excavation groove, and the excavating blade 22 and the stirring blade 23 of the central rotating means 20C are obliquely upward (in FIG. 8B). can be moved to the upper right), it is possible to excavate the side walls of the excavation at the desired depth, it is possible to widen the excavation easily.

[Fifth Embodiment]
Next, an excavation and agitation apparatus according to a fifth embodiment of the present invention will be described.
FIG. 9 is a view showing a rotating means according to the fifth embodiment of the present invention, and is a front view showing a configuration in which the right rotating means and the left rotating means can be refracted. FIG. 10 is a front view showing a configuration including a right rotating means and a left rotating means that can be refracted, showing a rotating means according to a fifth embodiment of the present invention.
The excavation stirring apparatus according to the fifth embodiment of the present invention has substantially the same configuration as the excavation stirring apparatus according to the second embodiment shown in FIG. As shown in FIG. 9, the right rotation means 20R and the left rotation means 20L having the same configuration are different in that they can be refracted.

In the excavation and agitation apparatus according to the fifth embodiment, the fixed shafts 30R and 30L of the right rotating means 20R and the left rotating means 20L are divided into upper fixed shafts 30Ra and 30La and lower fixed shafts 30Rb and 30Lb, and the upper fixed shaft 30Ra. , 30La is attached to the upper surface of the connecting member 24 at its lower end.
Further, the lower fixed shafts 30Rb and 30Lb are respectively attached to the lower surface of the connection member 24 via horizontal shaft members 24d and 24d, and the lower end portion of the right rotation means 20R is rotated around the horizontal axis toward the upper left in FIG. tilted to the lower end of the left rotational unit 20L is configured to tilt about a horizontal axis toward the upper right in FIG. That is, by tilting the lower fixed shafts 30Rb and 30Lb below the connecting member 24, the right rotation means 20R and the left rotation means 20L are refracted.
Reference numerals 24e and 24e are hydraulic cylinders for rotating the lower fixed shafts 30Rb and 30Lb of the rotating means 20R and 20L. The axial direction is arranged in the vertical direction, and each main body portion is an upper fixed shaft. The rod portions are attached to the lower side surfaces of 30Ra and 30La by brackets, and the rod portions are attached to the upper side surfaces of the lower fixed shafts 30Rb and 30Lb by brackets. The lower fixed shafts 30Rb and 30Lb are configured to tilt with the horizontal shaft members 24d as the support shafts by extending and contracting the hydraulic cylinder 24e. Further, since the hydraulic cylinders 24e are respectively provided in the rotating means 20R and 20L, the right rotating means 20R and the left rotating means 20L can be refracted independently.

In this way, by making each rotating means 20R, 20L refractable, each rotating means 20R, 20L is refracted in the excavation groove, and the excavating blade 22 and the stirring blade 23 of each rotating means 20R, 20L are obliquely upward ( can be moved to the right and left upper side) of FIG. 9, it is possible to excavate the side walls of the excavation at the desired depth, it is possible to widen the excavation easily.

  Further, by providing a refracted portion on the non-rotating fixed shafts 30R and 30L, the holes in the upper fixed shafts 30Ra and 30La and the holes in the lower fixed shafts 30Rb and 30Lb (see FIG. 3) by a flexible hose. Can be connected to supply the drive oil, drain the oil, and supply the solidifying agent. Therefore, the rotating shafts of the rotating means 20R and 20L can be refracted without making the structure of the rotating means 20R and 20L complicated. 21R and 21L can be driven to excavate and agitate the excavation groove.

Here, the upper fixed shaft 30RA, 30LA and the lower fixed shaft 30Rb, the number of 30Lb need not be identical, for example, two to the connecting member 24 which is supported by two upper fixed shaft 30 Ra, 30 La The above-described lower fixed shafts may be provided so as to be refracted, and an outer motor and a rotary shaft may be provided on each lower fixed shaft to constitute a rotating means. At this time, by branching the hose from the holes in the upper fixed shaft 30 Ra, 30 in La it is connected to each hole of the lower fixed shaft 30 Rb, within 30 Lb, driving oil lubrication, oil discharge and solidifying agent Can be supplied. The arrangement of the lower fixed shaft is not limited. For example, by arranging four lower fixed shafts on the four sides of the lower surface of the connecting member 24, a rectangular excavation groove can be constructed in plan view. .

  Furthermore, as shown in FIG. 10, without providing the central rotating means 20C, an excavating and stirring device composed of the right rotating means 20R and the left rotating means 20L that can be refracted may be configured. It can be set correspondingly.

As mentioned above, although an example about the suitable embodiment of the present invention was explained, the present invention is not limited to the above-mentioned embodiment, and design change is possible suitably in the range which does not deviate from the meaning of the present invention.
For example, the number of outer motors 40 or inner motors 50 installed on the fixed shaft 30 of each rotating means 20 is not limited, and is appropriately set according to various construction conditions such as soil soil, excavation and stirring. It is preferable to carry out efficiently.
In addition, by installing a measuring device that measures the position and depth of the rotary shafts 21C, 21R, and 21L in the excavation groove at the lower end of the fixed shafts 30C, 30R, and 30L, the excavation state in the excavation groove is grasped in real time. Thus, the construction may be accurately managed, and the excavation groove may be constructed with high accuracy. At this time, since the fixed shafts 30C, 30R, 30L do not rotate during excavation, the power cable or communication cable of the measuring device is inserted into the spare hole E (see FIG. 3) of the fixed shafts 30C, 30R, 30L and wired. Thus, the measuring device can be easily installed in the rotating means 20C, 20R, 20L.

It is the side view which showed the excavation stirring apparatus which concerns on 1st Embodiment of this invention. It is the front view which showed the rotation means which concerns on 1st Embodiment of this invention. It is the figure which showed the fixed axis | shaft of the rotation means which concerns on 1st Embodiment of this invention, (a) is AA sectional drawing of FIG. 2, (b) is BB sectional drawing of FIG. 2, (c) is FIG. It is CC sectional drawing of FIG. It is the figure which showed the rotation means which concerns on 2nd Embodiment of this invention, (a) is a front view of a rotation means, (b) is the figure which showed the other structure of the rotation means, The right side rotation means and the left side rotation means It is the front view which showed the structure which provided one outer motor in the. It is the figure which showed the other structure of the rotation means which concerns on 2nd Embodiment of this invention, and is the front view which showed the structure which provided the inner motor of the center rotation means in the center part of the height direction. It is the figure which showed the other structure of the rotation means which concerns on 2nd Embodiment of this invention, and is the front view which showed the structure by which the upper excavation blade is not provided in the right rotation means and the left rotation means. It is the figure which showed the rotation means which concerns on 3rd Embodiment of this invention, and is the front view which showed the structure which provided the outer motor and the inner motor in the right rotation means and the left rotation means. It is the figure which showed the rotation means which concerns on 4th Embodiment of this invention, (a) is the front view which showed the structure which a center rotation means can tilt, (b) is D- in the state which tilted the center rotation means. It is D sectional drawing. It is the figure which showed the rotation means which concerns on 5th Embodiment of this invention, and is the front view which showed the structure which the right rotation means and the left rotation means can refract. It is the figure which showed the rotation means which concerns on 5th Embodiment of this invention, and is the front view which showed the structure which consists of the right rotation means and left rotation means which can be refracted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Excavation stirring apparatus 2 Base machine 20C Central rotation means 20R Right rotation means 20L Left rotation means 21C Rotating shaft (central rotation means)
21R Rotating shaft (Right-side rotating means)
21L Rotating shaft (Left side rotating means)
22 excavating blade 23 stirring blade 30C fixed shaft (central rotating means)
30R fixed shaft (right rotation means)
30L fixed shaft (left rotation means)
40C outer motor (central rotating means)
40R outer motor (right rotation means)
40L outer motor (left rotation means)
50 Inner motor

Claims (5)

A base machine,
A plurality of rotating means supported by the base machine so as to be movable up and down,
Each rotating means is arranged in parallel to the base machine,
Each rotating means has a digging blade and a stirring blade, and excavating a digging groove with the digging blade, and a digging and stirring device for stirring the inside of the digging groove with the stirring blade,
Each rotating means includes
A fixed shaft;
A hydraulic motor in which the fixed shaft is inserted, and an output portion provided around the stirring blade is rotatable around the fixed shaft;
By being connected to the output portion of the hydraulic motor, the rotary shaft is rotatable about a concentric shaft with the fixed shaft, and includes a rotating shaft provided with the excavating blade at a lower portion and the stirring blade around the rotating shaft. And
The at least one rotating means includes the excavating blade at the upper part of the rotating shaft. A base machine,
Three rotating means supported by the base machine to be movable up and down,
Each rotating means is arranged in parallel to the base machine,
Each rotating means has a digging blade and a stirring blade, and excavating a digging groove with the digging blade, and a digging and stirring device for stirring the inside of the digging groove with the stirring blade,
In the three rotation means, the rotation means arranged in the center is
A first hydraulic motor;
It is rotatable by being inserted into the output part of the first hydraulic motor, and comprises a rotating shaft provided with the excavating blade at the lower part and the stirring blade around it,
In the three rotation means, each of the rotation means arranged at both ends is
A fixed shaft;
A second hydraulic motor in which the fixed shaft is inserted, and an output portion provided around the stirring blade is rotatable around the fixed shaft;
By being connected to the output portion of the second hydraulic motor, the rotary shaft is rotatable about a concentric shaft with the fixed shaft, and includes the excavating blade in the lower portion and the rotating shaft provided with the agitating blade around. Consisting of
The at least one rotating means includes the excavating blade at the upper part of the rotating shaft. A base machine,
Three rotating means supported by the base machine to be movable up and down,
Each rotating means is arranged in parallel to the base machine,
Each rotating means has a digging blade and a stirring blade, and excavating a digging groove with the digging blade, and a digging and stirring device for stirring the inside of the digging groove with the stirring blade,
In the three rotation means, the rotation means arranged in the center is
A first hydraulic motor;
It is rotatable by being inserted into the output part of the first hydraulic motor, and comprises a first rotating shaft provided with the excavating blade at the lower part and the stirring blade around it,
In the three rotation means, each of the rotation means arranged at both ends is
A fixed shaft;
A second hydraulic motor in which the fixed shaft is inserted, and an output portion provided around the stirring blade is rotatable around the fixed shaft;
By being connected to the output part of the second hydraulic motor, the second rotary shaft is rotatable around the concentric shaft with the fixed shaft, and has the stirring blades around.
A third hydraulic motor supported by the fixed shaft;
It is rotatable by being inserted into the output part of the third hydraulic motor, and comprises a third rotating shaft provided with the excavating blade in the lower part and provided with the agitating blade at the periphery,
The at least one rotating means includes the excavating blade at the upper part of the rotating shaft. The excavation and agitation device according to any one of claims 1 to 3, wherein at least one of the rotating means is capable of tilting a lower end portion of the rotating means around a horizontal axis . The ground improvement method characterized by including each process of the following 1st process-4th process.
(1) The rotating shaft is moved by moving the base machine of the excavating and agitating device according to any one of claims 1 to 4 to a side of a predetermined position for excavation and lowering the rotating means. A first step of bringing the excavating blade installed on the ground into contact with the ground surface;
(2) Rotating the rotating shaft of each rotating means, excavating the ground with the excavating blade, and sequentially lowering the rotating means by the base machine to construct the excavating groove with a predetermined depth, A second step of disposing the hydraulic motor of each rotating means in the excavation groove;
(3) A third step of injecting a solidifying agent into the excavation groove while excavating the ground with the rotating means, and stirring and mixing the excavated soil and the solidifying agent with the stirring blade.
(4) A fourth step in which, while stirring and mixing the excavated sediment and the solidifying agent, the rotating means are raised and pulled up from the excavated groove to harden the excavated sediment in the excavated groove.

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