JP7029515B1 - Manufacturing method of improved consolidated body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a stop of a free-rotating wing without an increase in excavation resistance or hindering the progress of excavation due to a free-rotating wing provided on an excavation shaft, and to use the free-rotating wing to excavate soil. Provided is a method for producing an improved solidified body and a ground improving machine, which can obtain a good mixing and agitation of excavated soil and a solidifying agent so as to prevent co-rotation of the mixed fluid. SOLUTION: A rotary free wing 30 has a length such that its tip 35 does not protrude to the outside of an excavation diameter circle which is a circle drawn by the tip of an excavation wing 20 in a plan view and rotation of an excavation shaft 10. A rotation stop member 160 for stopping the rotary free blade 30 from rotating around the excavation shaft 10 in the mixing and stirring process is penetrated into the excavated soil in the mixing and stirring process so as to correspond to the descent of the excavation shaft 10. It is moved downward to stop the free rotation blade 30 from rotating around the excavation shaft 10 at the lower end portion or the portion near the lower end portion of the rotation stop member 160. The co-rotation prevention of the free rotation blade 30 can be obtained without problems such as an increase in excavation resistance. [Selection diagram] FIG. 4

Description

The present invention relates to a method for manufacturing an improved consolidated solid, and more specifically, in civil engineering, foundation work of construction, etc., while excavating soft ground into a columnar shape, for example, from the tip of an excavation shaft, lime-based or cement. The system's slurry-like solidifying agent (hereinafter, also simply referred to as a solidifying agent) is discharged, and this solidifying agent and the excavated excavated soil (unraveled earth and sand, etc.) are mixed and stirred, and then solidified. The present invention relates to a method for producing an improved consolidated body, which solidifies and forms a soft ground into a columnar shape or the like to improve the strength.

In a ground improvement machine used for the production of this kind of improved solidified body, the ground is excavated, a solidifying agent is supplied into the excavated excavated soil, and the solidifying agent and the excavated soil are mixed and stirred. The mechanism or structure (excavation mixing and stirring means) responsible for the stirring process is the simplest structure having an excavation shaft rotating around the vertical axis and an excavation blade provided near the lower end (tip) thereof. In addition to the excavation blade, a structure having one or a plurality of stirring blades above and below, which has a smaller lateral protrusion than the excavation blade, is basically provided above the excavation blade. For example, in a structure having a stirring blade, the tip of a rotating excavation shaft is pushed into the ground to excavate the ground with the excavation blade, and the stirring blade above the excavated soil and the solidifying agent discharged are used. Is mixed and stirred. However, in this case, especially in the ground improvement work in the highly viscous clay layer, excavated soil and a mixture of excavated soil and solidifying agent (mixed fluid) are excavated around the excavation shaft and agitated. There is a problem that the solidifying agent and the excavated soil are not mixed evenly because they tend to rotate together with the wing (rotate together), so-called co-rotation. And, such a problem also exists in the structure having no stirring blade.

Under these circumstances, a rotating excavation shaft and above the excavation blade provided near the tip (lower end) of the rotating excavation shaft (below the stirring blade if there is a stirring blade, and having a plurality of stirring blades above and below). Then, (between the upper and lower parts of the stirring blade), it has a support (annular body) attached by freely fitting the rotation relative to the excavation axis around the vertical axis line, and this support (annular body). A ground improvement device is known in which a protruding wing called a co-rotation prevention wing, in which the amount of lateral protrusion from the excavation shaft is large (long) and the amount of protrusion of the excavation wing is large, is provided on the annular body). (See, for example, Patent Document 1). Such a co-rotation prevention wing is also referred to as a "rotation free wing" in the present application because the relative rotation around the vertical axis line (rotation axis) of the excavation axis is free. In the present application, "excavating the ground" does not mean digging the ground and draining the soil to form a concave hole, but "relaxing" the earth and sand of the ground to be excavated. Means. That is, in the present application, "excavating the ground" means, for example, like an earth auger, by rotating a screw provided around a rotation axis (vertical axis), the earth and sand excavated by the auger head at the tip is excavated. It does not mean that the ground is dug and a concave hole is made by drilling (empty digging the ground (ground)) while continuously discharging (soil) upward with a screw, but the earth and sand of the ground is removed. , Means to loosen.

In the ground improvement device (excavation mixing and stirring means of the excavation mixing machine) described in Patent Document 1, the tip (lower end) of the excavation shaft is pushed into the ground while rotating the excavation axis with the ground surface (ground) as the excavation start surface. When the excavation is started by moving and excavating, the tip of the free-rotating wing (co-rotation prevention wing) hits the outside of the periphery of the excavation diameter circle on the ground surface (unexcavated soil). It will be forcibly pushed (bitten) inside. By forcibly pushing the tip of the free-rotating blade (co-rotation prevention blade) into such unexcavated soil, the free-rotating blade does not rotate around the axis of the excavation axis. The presence of the free-rotating wing, whose rotation is stopped in this way, prevents the excavated soil (soil mass) and mixed fluid (simply referred to as “excavated soil”) as described above from co-rotating around the excavation axis. According to the ground improvement device described in Patent Document 1, the mixing and stirring property (homogeneity by mixing) between the excavated soil and the solidifying agent in the downward excavation process is enhanced. be. That is, the excavated soil or the like that tries to rotate together around the axis of the excavation axis is divided above and below the free rotating wing because the co-rotation is prevented at least at the height of the free rotating wing where the rotation is stopped. Therefore, the excavated soil is mixed and agitated more uniformly around the excavation axis. In the present application, the "excavation diameter circle" means a circle drawn by the tip of the excavation blade in a plan view and rotation of the excavation shaft, but is also referred to as an excavation diameter.

Special Publication No. 58-29374

However, in the excavation mixing and stirring means (ground improvement device) for excavating the ground in the above-mentioned ground improvement machine, the means for stopping the rotation around the excavation axis of the free-rotating wing, which is a co-rotation prevention wing, excavates the tip of the free-rotating wing. Since it depends on forced pushing (biting) into the unexcavated soil outside the circle, it inevitably increases the excavation resistance and the accompanying increase in the downward power of the excavation shaft (larger power). Bring. Moreover, in order to ensure the prevention of rotation around the excavation axis of the free-rotating wing (co-rotation prevention wing), the tip of the free-rotating wing is unexcavated soil outside the excavation diameter (in the ground not subject to excavation). It is necessary to secure the protrusion length as large (long) as possible in the plan view of biting (entering).

On the other hand, the longer the protrusion length (the amount of biting into unexcavated soil) of the tip of this free-rotating wing, the higher the frequency or possibility that the tip will collide with rubble, stones, and rocks mixed in the ground. Become. If such a collision occurs, the progress of excavation may be delayed, and in some cases, the excavation may be stopped, which may lead to a serious problem that the desired ground improvement work cannot be performed. In order not to cause such a problem and to improve workability, the protruding length of the tip of the free-rotating blade is apt to be set short. On the other hand, if the protruding length of the tip of the free-rotating blade (the amount of biting into the unexcavated soil) is short, the rotational power of the excavated soil (soil mass) or mixed fluid that tries to rotate (co-rotate) in the direction of rotation by the excavated blade. Therefore, the free-rotating wing may not be able to stop in a plan view. That is, the tip of the free-rotating blade may slip and rotate around the excavation axis. In such a case, since the co-rotation prevention effect cannot be obtained, a homogeneous improved consolidated body cannot be obtained. The presence or absence of such rotation of the free-rotating wing is an event that occurs in the ground (underground), so it is difficult to detect it, but its homogeneity due to the excavation of the improved consolidated body after construction, etc. Known by quality inspection (digging inspection). In this way, if an attempt is made to reliably prevent co-rotation with the conventional co-rotation prevention wing (rotary free wing), the construction efficiency will deteriorate, but the protrusion length (length of biting into unexcavated soil) will be shortened. If this happens, the rotation of the co-rotation prevention blade will be caused, and favorable mixing and stirring of the excavated soil and the solidifying agent cannot be obtained, and as a result, the quality of the improved solidified body will be deteriorated.

The present invention has been made in view of the above problems, and the free-rotating wing has no increase in excavation resistance or hindrance to the progress of excavation due to the free-rotating wing (co-rotation prevention wing) in the above-mentioned ground improvement machine. To provide a method for producing an improved solidified body, which ensures a stoppage, provides an inhibitory effect on the co-rotation of the excavated soil and the mixed fluid, and obtains a good mixing and agitation of the excavated soil and the solidifying agent. Is the purpose.

According to the first aspect of the present invention, as the excavation mixing and stirring means for the ground, the excavation shaft is rotated around the vertical axis line to move up and down, and the excavation shaft is rotated at the lower end or the vicinity of the lower end together with the excavation shaft. Using a ground improvement machine provided with a provided excavation wing and a free-rotating wing provided so as to freely rotate and project laterally with respect to the excavation axis at a predetermined position above the excavation wing.
The solidifying agent is supplied into the excavated soil excavated while excavating the ground to a predetermined depth with the rotating excavation blade by rotating the excavation shaft to move downward, and the solidifying agent and the excavated soil are combined. In the method for producing an improved consolidated body, which forms an improved consolidated body in the soil through a mixing and stirring step of mixing and stirring.
The free-rotating wing has a length whose tip does not protrude outside the excavation diameter circle, which is a circle drawn by the tip of the excavation wing in a plan view and rotation of the excavation axis.
A rotation stop member for stopping the rotation of the free rotation blade around the excavation axis in the mixing and stirring step is provided in a device different from the ground improvement machine so as to be movable up and down.
In the mixing and stirring step, the rotation stop member provided in the other device is penetrated into the excavated soil and is moved downward so as to correspond to the downward movement of the excavation shaft, and a predetermined portion of the rotation stop member is provided. The free-rotating wing is characterized by stopping the rotation around the excavation axis.

As the "reference invention 1" different from the present invention, as the excavation mixing and stirring means of the ground, an excavation shaft that rotates around the vertical axis and moves up and down, and the excavation near the lower end or the lower end of the excavation shaft. Ground improvement provided with an excavation wing provided to rotate with the shaft and a free rotation wing provided to freely rotate and project laterally with respect to the excavation shaft at a predetermined position above the excavation wing. It ’s a machine,
The solidifying agent is supplied into the excavated soil excavated while excavating the ground to a predetermined depth with the rotating excavation blade by rotating the excavation shaft to move downward, and the solidifying agent and the excavated soil are combined. In a ground improvement machine used in a method for producing an improved consolidated body, which forms an improved consolidated body in the ground through a mixing and stirring step of mixing and stirring.
The free-rotating wing has a length such that its tip does not protrude outside the excavation diameter circle, which is a circle drawn by the tip of the excavation blade in a plan view due to the rotation of the excavation shaft.
In the ground improvement machine, in a plan view, inside the excavation diameter circle, the rotary free wing moves up and down together with the excavation axis without rotating around the excavation axis, and the rotary free wing excavates the excavation by its own predetermined portion. Some are characterized by comprising a rotation stop member configured to stop rotation around an axis.

Further, as the "reference invention 2" different from the present invention, the predetermined portion of the rotation stop member and the rotation free wing do not rotate in either the forward or reverse direction around the excavation axis. There is a ground improvement machine according to the above- mentioned reference invention 1 , which is characterized by having a structure.

In the method for manufacturing an improved consolidated body according to claim 1, the tip of the free-rotating wing in the ground improvement machine used therein is a circle drawn by the tip of the digging wing by the rotation of the digging shaft in a plan view. Since the length is such that it does not protrude to the outside of a certain excavation diameter circle, in the mixing and stirring step, the tip of the rotary free blade is located on the relatively hard ground (unexcavated soil) outside the excavation diameter circle. ) Will not be forced into. As a result, excavation resistance can be reduced as compared with the method (construction) of manufacturing an improved consolidated body using a conventional ground improvement machine in which the tip of the free-rotating wing is forcibly pushed into unexcavated soil. However, the tip of the free-rotating wing does not collide with rubble, stones, etc. in unexcavated soil, causing problems such as delaying the progress of excavation and interrupting construction.

On the other hand, although the free-rotating blade has a length that does not protrude to the outside of the excavation diameter circle in a plan view, in the present invention, the rotary free blade is provided in the other device in the mixing and stirring step. The rotation stop member penetrates into the excavated soil and is moved downward so as to correspond to the downward movement (descending) of the excavation shaft, and the rotation free blade rotates around the excavation shaft by a predetermined portion of the rotation stop member. I'm going to stop. Therefore, even if the excavated soil or the mixed fluid (hereinafter, also referred to as “excavated soil”) moves so as to rotate around the excavation axis in the mixing and stirring step, the rotary free blade does not rotate. With the free rotation wing, the same operation and effect as the conventional co-rotation prevention wing can be obtained. That is, even if the excavated soil or the like moves so as to rotate around the excavation axis and tries to rotate the free rotation blade, the free rotation blade always hits a predetermined portion of the rotation stop member within one rotation, and more than that. Do not rotate. As described above, according to the present invention, even if the excavated soil or the like rotates (co-rotates) around the excavation axis in the mixing and stirring step, the excavated soil or the like is located at the height position of the rotary free blade and in the vicinity thereof. Since the rotation (co-rotation) can be surely stopped, preferable mixing and stirring can be obtained.

According to the first aspect of the present invention, unlike the conventional rotary free wing, the excavation resistance (penetration resistance) does not increase due to the forced pushing of the tip portion into the unexcavated soil, and the tip thereof does not increase. There is no problem of delay or interruption of construction due to the collision of the part with gravel, stone, rock, etc., and the rotation prevention of the free rotation blade can be obtained. Therefore, it is possible to efficiently proceed with the ground improvement work in which a good improved solidified body having excellent mixing and stirring properties of the excavated soil and the solidifying agent can be obtained.

The "predetermined portion of the rotation stop member" in the invention according to claim 1 basically means a portion of the rotation stop member corresponding to the height of the free rotation blade. Therefore, when the free rotation blade is provided in only one step in the vertical direction of the excavation shaft, the "predetermined portion of the rotation stop member" is a portion that hits the free rotation blade and stops its rotation. It is preferable to use the lower end portion or the portion near the lower end portion of the rotation stop member. However, since the rotation stop member only needs to stop the free rotation of the free rotation blade, for example, the attachment portion of the free rotation blade to the excavation shaft (the clamp portion at the base of the free rotation blade) is free to rotate. Although it is not the wing itself, the predetermined portion may be engaged or the like to be engaged with a portion connected to the wing (a portion that rotates together with the free-rotating wing) to stop the rotation.

In addition to the excavation blade, the excavation shaft in the ground improvement machine used in the present invention may be above the excavation blade and at least above the free rotation blade or below the free rotation blade as described above. One or more stirring blades may be attached (fixed). However, when the stirring blade is provided above the free rotation blade, not only the length does not protrude to the outside of the excavation diameter circle, but also the rotation stop member is not interfered with or the rotation stop member is used. Avoid interfering with the stirring blade. Further, in the present invention, the rotary free blade may be provided in a plurality of upper and lower parts.

In the method for manufacturing the improved consolidated body according to claim 1, the "device different from the ground improving machine" is an arm provided in the construction machine such as a backhoe or a power shovel, or a truck with a crane. Any device such as a construction machine provided with a mechanism capable of moving the rotation stop member up and down by moving up and down. When such a construction machine or the like is used, the rotation stop member is a vertical axis or a bar extending in the vertical direction, and the rotation stop member is hung from the tip of an arm in a backhoe, a power shovel, or a truck with a crane. It is attached in a shape (extending in the vertical direction) so that it does not interfere with the excavation blades and other parts of the ground improvement machine inside the excavation diameter circle, and it depends on the lower end of the rotation stop member or the part near the lower end. In the mixing and stirring step, the rotation stop member is driven to move the tip of the arm up and down in accordance with the vertical movement of the excavation shaft so that the free rotation of the free-rotating wing around the excavation shaft can be stopped. You can move it up and down by controlling it.

The invention of the ground improvement machine of Reference Invention 1 has the above configuration. Therefore, when the improved solidified body is formed in the ground by using this ground improving machine, the same operation and effect as the method for producing the improved consolidated body according to claim 1 can be obtained. Since the ground improvement machine itself is provided with the rotation stop member having the above configuration, the device is "different from the ground improvement machine" as in the method for manufacturing the improved consolidated body according to the first aspect of the invention. The rotation stop member provided in the ground improvement machine can stop the rotation of the free rotation blade without requiring special control. Therefore, using the ground improvement machine of Reference Invention 1 , the excavation shaft is rotated and moved downward, and the solidifying agent is supplied to the excavated soil excavated while excavating the ground to a predetermined depth with the rotating excavation blade. Then, by undergoing a mixing and stirring step of mixing and stirring the solidifying agent and the excavated soil, the desired improved consolidation in the ground is simpler and more efficient than the invention according to claim 1. Can form a body.

The rotation stop member moves up and down together with the excavation shaft and hits the rotation free wing by its own predetermined portion (for example, a lower end portion or a portion near the lower end), so that the rotation free wing excavates. It may be configured to stop the rotation around the axis, but as in the ground improvement machine of the reference invention 2, the predetermined portion of the rotation stop member and the rotation free wing are the rotation free wing. However, it is preferable to have a structure that does not rotate in either the forward or reverse direction around the excavation axis. However, regardless of such assembly, the rotation stop member only needs to be able to stop the rotation free blade from rotating around the excavation axis, and thus, as in the invention according to claim 1, for example, for example. The predetermined portion, such as the attachment portion of the free-rotating wing to the excavation shaft (the clamp portion at the base of the free-rotating wing), is not the free-rotating wing itself, but is connected to the free-rotating wing (the portion that rotates together with the free-rotating wing). May be engaged to stop the rotation. Also in the ground improvement machine of Reference Invention 1 or 2 , as described above for the ground improvement machine used in the invention of claim 1, a stirring blade is attached to the excavation shaft in addition to the excavation blade. It may be fixed (fixed).

The perspective view which shows the schematic structure of the ground improvement machine used in the Example of Embodiment of this invention according to claim 1. The enlarged front view (elevation view) which shows the schematic structure of the ground improvement machine of FIG. A schematic front view showing a part of the ground improvement machine omitted to explain the state of ground improvement using the ground improvement machine of FIG. 1 and the rotation stop member provided in another device (backhoe). figure. In FIG. 3, an enlargement for explanation of the P1 part of FIG. 3 in a state where the rotation stop member provided in another device (backhoe) is engaged with the rotation free wing of the ground improvement machine to stop the rotation of the rotation free wing. figure. FIG. 4 is a schematic view (plan view) of the excavation shaft, the excavation diameter circle, and the like as viewed from above. FIG. 4 is a view seen from the direction of arrow A, and is a partial view illustrating a state in which a predetermined portion of the rotation stop member is engaged with the rotation free wing to stop the rotation of the rotation free wing. FIG. 6 is a partial view illustrating a state in which a predetermined portion of the rotation stop member forms a bifurcation and the tip portion of the free rotation wing is sandwiched in the bifurcation. A is a front view of the free rotation wing. FIG. B is a side view of A. FIG. 7 is a partial side view illustrating a state in which a predetermined portion of the rotation stop member is used as a frame instead of the bifurcation of FIG. 7 and the tip end portion of the free rotation blade is passed through the frame. The perspective view which shows the schematic structure of the embodiment of the ground improvement machine of Reference Invention 1 . The enlarged front view (elevation view) which shows the schematic structure of the ground improvement machine of FIG. FIG. 10 is an enlarged view showing only the main part such as the excavation shaft. FIG. 11 is a schematic view (plan view) of the excavation shaft, the excavation diameter circle, and the like as viewed from above. The enlarged left side view which showed only the main part such as excavation shaft which explains the deformation example of the predetermined part of the rotation stop member in the ground improvement machine of FIG.

An example in which the method for producing the improved consolidated body of the present invention is embodied will be described with reference to FIGS. 1 to 6. The excavation machine 100 used in this example method is an excavation shaft (circular pipe) that rotates around the vertical axis and moves up and down in front of the ground improvement machine main body 103 (left side in FIG. 1) as a means for excavating and mixing and stirring the ground. ) 10, a pair of left and right excavation blades 20 provided (fixed) to rotate with the excavation shaft 10 at the lower end or near the lower end of the excavation shaft 10, and the excavation shaft 10 at a predetermined position above the excavation blade 20. It is provided with a pair of left and right free-rotating blades 30 that are freely rotatable with respect to the excavation shaft 10 and are provided so as to project laterally to the excavation shaft 10. The free-rotating wing 30 has a length (excavation wing) whose tip 35 does not protrude to the outside of the excavation diameter circle Ke, which is a circle drawn by the tip of the excavation wing 20 due to the rotation of the excavation shaft 10 in a plan view (viewed from above). It is supposed to have a length shorter than 20 (see FIG. 5). In this example, the free-rotating wing 30 has two single wing (left and right pair wing) in a state where the movement in the vertical direction is restricted by the two upper and lower fixed flanges 13 and 13 provided on the excavation shaft 10. The excavation shaft 10 is sandwiched between a pair of clamps (mounting portions) 33 provided at the base end thereof, bolted, and mounted so as to be rotatable with respect to the excavation shaft 10.

The excavation shaft 10 is held substantially vertically in front of the ground improvement machine main body 103, is connected to the rotation shaft of the motor 50 at the upper end of the excavation shaft 10, and is provided so as to be rotationally controlled around the vertical axis. The motor 50 is attached to a bracket 70 that can be moved up and down (up and down) with respect to the elevating guide (holding column) 60 that is held substantially vertically in front of the ground improvement machine main body 103. The angle of the elevating guide (holding column) 60 can be adjusted by the hydraulic cylinder 70, and the excavation shaft 10 is configured so that the angle can be adjusted vertically by this adjustment. Further, the excavation shaft 10 is in the excavation shaft guide 80 attached to the lower part (the portion near the lower end) of the elevating guide (holding column) 60 of the ground improvement machine main body 103 in the state of rotation by the motor 50 or in the state of rotation stop. It is installed so that it penetrates the guide hole up and down so that it can move up and down (up and down) in a stable manner. As a result, the excavation shaft 10 is configured to be held substantially vertically, to be rotationally controlled around the vertical axis, and to move up and down (up and down) according to the up and down movement of the bracket 70.

The vertical movement of the bracket 70 is set to be driven and controlled by a vertical drive means (for example, chain drive) (for example, chain drive) provided on the lift guide (holding column) 60 or the like. Further, in this example, in the upward movement, that is, in pulling up the excavation shaft 10, the mount (or bracket 70) of the motor 50 is wound by a wire 93 wound around a sheave 90 attached to the upper part of the holding column 60. It is configured to assist in pulling up. Specifically, the wire 93 coupled to the mount (or bracket 70) of the motor 50 is configured to drive a winch 95 provided on the front portion of the ground improvement machine main body 103 and wind it up.

The illustrated ground improvement machine 100 is provided with a moving (traveling) means 105, and an operation table 107 is provided on the upper part of the ground improvement machine main body 103, so that the operator can operate the excavation shaft 10 by rotating, moving up and down, and the like. , It is set to operate. Further, the ground improvement machine main body 103 is provided with support legs 109 at the four corners in a plan view, and is set to maintain the stability of the ground improvement machine 100 at the time of construction. In the vicinity of the bracket 70 at the upper end of the excavation shaft 10, for example, a flexible tube for discharging a solidifying agent (aqueous solution) from a discharge port 15 (see FIG. 4 and the like) at the lower end of the excavation shaft 10 and supplying it into the excavated soil. One end of the 112 is connected and the other end is connected to a pumping source (not shown) of the solidifying agent.

In the ground improvement work using such a ground improvement machine 100 (manufacturing of an improved consolidation body that forms an improved consolidation body in the ground), in addition to the ground improvement machine 100, for example, a device such as a backhoe 150 or the like. (Construction machine) is prepared, and as shown in FIGS. 3 and 4, a rotation stop member (bar member) 160 extending vertically via the mounting portion 157 is attached to the tip (bucket) 155 or the like of the arm 153. , Attach it in a hanging shape (approximately vertical). Then, in a plan view, inside the excavation diameter circle Ke in the ground (ground) G scheduled for excavation (ground improvement), and inside the tip 35 of the free rotation wing 30 when the free rotation wing 30 rotates. At the position of, the tip 155 of the arm 153 is moved up and down so as to match (synchronize and synchronize) with the up and down movement of the excavation shaft 10, and the rotation stop member 160 is set to move up and down.

That is, as shown in FIGS. 3 and 4, the excavation shaft 10 is positioned at a predetermined position for ground improvement, rotated and descended, and the rotating excavation blade 20 requests the ground G from the ground in the construction. By supplying a solidifying agent into the excavated soil excavated while excavating to a predetermined depth, and mixing and stirring the solidifying agent and the excavated excavated soil, the improved solidification is carried out in the ground. A body is formed, but in the mixing and stirring step, the rotation stop member 160 provided at the tip 155 of the arm 153 of the back hoe 150 of this example, which is another device, is attached to the tip 155 of the arm 153. It is moved up and down to penetrate into the excavated soil and move down to correspond to the descent of the excavation shaft 10. In the downward movement of the rotation stop member 160, the rotation free blade 30 is stopped from rotating around the excavation shaft 10 by a predetermined portion of the rotation stopper 160 (in this example, the lower end portion or the portion near the lower end thereof). The rotation stop member 160 is downwardly moved and controlled so that the predetermined portion is held at the height of the free rotation blade 30. As a result, even if the free-rotating wing 30 tries to rotate with the rotational power of the excavated soil or the like that tries to rotate (co-rotate) around the excavation shaft 10, the free-rotating wing 30 is placed on a predetermined portion (side) of the rotation stop member 160. 30 hits, and the rotation of the free rotation blade 30 is structurally stopped. That is, in this example, since the rotary free blade 30 has a structure of a pair of left and right, no matter whether the excavation shaft 10 is rotated in the forward or reverse direction, within half a rotation, a predetermined portion (side portion) of the rotation stop member 160 is provided. When it hits, the rotation is stopped.

As described above, in this example, in the excavated soil excavated while rotating the excavation shaft 10 to descend by using the ground improvement machine 100 having the above configuration and excavating the ground G to a predetermined depth with the rotating excavation blade 20. The solidifying agent is supplied to the excavation and the excavated excavated soil is mixed and stirred. In the mixing and stirring step, the rotation stop member 160 provided in another device is excavated. It is moved up and down at the same speed as or substantially the same as the vertical movement of the shaft 10 and penetrates into the excavated soil to stop the free rotation of the free-rotating wing 30 around the excavation shaft 10. Therefore, in this mixing and stirring step, even if the excavated soil or the mixture (mixed fluid) of the excavated soil and the solidifying agent moves so as to rotate around the excavation shaft 10, the rotating free blade 30 that does not rotate causes the excavated soil. The same action and effect as the conventional co-rotation prevention wing can be obtained. Moreover, since the rotation of the free rotation blade 30 is reliably stopped at a predetermined portion of the rotation stop member 160, excavated soil is excavated at or near the height position of the free rotation blade 30 whose height changes in the mixing and stirring step. Rotation (co-rotation) such as, etc. can be reliably stopped, and preferable mixing and stirring can be obtained. As a result, after the completion of the mixing and stirring step, the excavation shaft 10 and the rotation stop member 160 are pulled up from the ground, and then a good improved solidified body is obtained.

In the mixing and stirring step, the excavation resistance (penetration resistance) does not increase due to the forced pushing of the tip (tip portion) 35 into the unexcavated soil unlike the conventional rotary free blade 30, and the excavation resistance (penetration resistance) does not increase. There are no problems such as delays or interruptions in construction due to collisions with gravel, stones, rocks, etc. at the tip. Therefore, it is possible to efficiently proceed with the ground improvement work in which a good improved solidified body having excellent mixing and stirring properties of the excavated soil and the solidifying agent can be obtained. Here, the improved consolidated body (unit) has a predetermined height under the ground where mixing and stirring are performed, with the excavation diameter circle Ke as the outer diameter.

It should be noted that the predetermined portion of the rotation stop member 160 (in this example, the lower end portion or the portion near the lower end) is the rotation free wing 30 at the stage where the rotation free wing 30 is located on the ground (on the ground G) and can be visually observed during construction. It is preferable that the blade is located at the height of the free-rotating blade 30 so as not to rotate, and the excavation shaft 10 is moved up and down at the same speed according to the up and down movement of the excavation shaft 10. Since the free rotation blade 30 located underground (underground) cannot be visually observed, the lower end of the rotation stop member 160 is located at the upper part (upper edge) of the free rotation blade 30 when the rotation stop member 160 penetrates into the excavated soil. This is because there is a risk of collision, but by doing so, the risk can be eliminated. Then, in this case, as shown in FIG. 7, the lower end portion, which is a predetermined portion of the rotation stop member 160, is made into a bifurcated 165, and the rotary free wing 30 is sandwiched between the bifurcated 165 to rotate. The rotation of the free wing 30 may be stopped (see FIG. 7-B). By doing so, the rotation of the free rotation blade 30 can be stopped at all times regardless of the forward rotation and the reverse rotation (clockwise rotation and counterclockwise rotation) of the excavation shaft 10.

Further, in the above example, the vertical movement of the rotation stop member 160 is attached to the tip end 155 of the arm 153 of the backhoe 150, which is another device, at the upper end portion or the vicinity of the upper end portion of the rotation stop member 160, and the vertical movement of the excavation shaft 10 is performed. The tip 155 of the arm 153 is moved up and down in accordance with the above, but a rod-shaped rotation stopper 160 extending up and down is freely attached to the tip 155 of the arm 153 of another device (for example, a backhoe). While a slideable guide is provided, as shown in FIG. 8, at the lower end of the rotation stop member 160, for example, a frame (for example, a square) that penetrates sideways instead of the bifurcated 165 as shown in FIG. A frame (hole) 167 is provided, and as described above, the tip 35 of the free-rotating wing 30 is passed through the frame (hole) at the stage where it can be visually observed during construction, and the free-rotating wing 30 (excavation shaft 10) is provided. The rotation stop member 160 may be moved up and down by moving up and down. By doing so, in another device, the rotation stop member 160 can be moved downward (upward) so as to correspond to the downward movement (upward) of the excavation shaft 10 without controlling the drive of the vertical movement. So it's convenient.

In the above example, the ground improvement machine 100 without a stirring blade is illustrated, but the excavation shaft 10 is separately provided on the excavation shaft 10 above the rotary free blade 30, for example, as shown by a two-dot chain line in FIG. The stirring blade 40 may be provided. In the case where the stirring blade 40 is provided above the free rotation blade 30, the stirring blade 40 has a length that does not interfere with the vertical movement of the rotation stop member 160, or the rotation stop member 160 is used as the stirring blade. It suffices to control the movement up and down at a position where it does not interfere. In order to improve the ground deep into the ground, if the excavation shaft is long, a plurality of free-rotating blades 30 may be provided at the top and bottom, and the stirring blade may also be provided with a rotation stop member. A plurality of upper and lower blades may be provided under the condition that the rotation of the free-rotating blade is not hindered.

In the above example, a device different from the ground improvement machine 100 is used, and the rotation stop member 160 is provided in the other device (for example, a backhoe) and moves up and down so as to be synchronized with or synchronized with the vertical movement of the excavation shaft 10. I did . Next, based on FIGS. 9 to 12, the rotation stop member 160 is attached to the ground improvement machine itself in parallel with the excavation shaft 10 so as to move up and down at the same time as the excavation shaft 10 . Will describe an example of an embodiment of the ground improvement machine 200 of another reference invention 1 (hereinafter, also referred to as “reference invention”) . However, the ground improvement machine 200 of Reference Invention 1 is different from the ground improvement machine 100 in the above example only in that a rotation stop member 160 and a configuration for mounting the rotation stop member 160 are added, so that the same parts are used. Have the same reference numerals and only the differences will be described.

As shown in FIGS. A rod-shaped extension on the lower surface of the bracket 70 or the bracket overhanging portion 73 provided so as to extend laterally from the mount of the motor 50 attached to the bracket 70, in a plan view, inside the excavation diameter circle Ke. The upper end of the rotation stop member 160 is fixed or suspended. The rotation stop member (bar body) 160 is maintained at an appropriate distance from the excavation shaft 10 and is provided in a hanging shape downward from the lower surface of the bracket overhanging portion 73 in parallel with the excavation shaft 10. Such a rotation stop member (in this example, a round bar) 160 is above and below the lower end portion or a portion near the lower end (near the lower end portion) so as to be located at the lower edge (height portion) of the free rotation blade 30. The length is set. In this example, the rotation stop member 160 vertically penetrates the guide hole provided in the guide overhanging portion 83 provided so as to laterally project from the excavation shaft guide 80 that guides the vertical movement of the excavation shaft 10. It is attached in a state of sliding up and down, and is capable of stable up and down movement (up and down) according to the up and down movement of the bracket 70 together with the excavation shaft 10. In the ground improvement machine 200 of this example (example of the embodiment of the reference invention) having such a configuration, the rotation stop member 160 does not rotate around the excavation axis 10 inside the excavation diameter circle Ke in a plan view. The predetermined portion of the rotation stop member 160 can be engaged with the free rotation blade 30 without requiring any control while moving up and down together with the excavation shaft 10. Therefore, when the ground improvement machine 200 of this example (example of the embodiment of the reference invention) is used to improve the ground, the rotary free blade 30 rotates around the excavation shaft 10 by the rotational power of the excavated soil or the like in the mixing and stirring step. Even if you try to rotate, you can surely stop the rotation.

That is, in the ground improvement work (the production of the improved consolidation body forming the improved consolidation body in the ground) using the ground improvement machine 200 of the reference invention , the excavation shaft 10 is rotated to descend and rotate. The above-mentioned improvement is simply performed by supplying a solidifying agent into the excavated soil excavated while excavating the ground G to a predetermined depth with the excavation blade 20 and mixing and stirring the solidifying agent and the excavated excavated soil. A preferred improved consolidated body similar to the method for producing a consolidated body can be formed in the ground. That is, since the ground improvement machine 200 itself includes the rotation stop member 160 having the above configuration, as in the ground improvement work using the ground improvement machine 100 as described above, "another device (for example, backhoe 150)". The rotation stop member 160 provided in the ground improvement machine 200 can automatically stop the rotation of the free rotation blade 30. Therefore, the ground is used by using such a ground improvement machine 200. When performing improvement work, it is possible to form the desired improved consolidation body in the ground more easily and efficiently than when performing ground improvement work using "another device" as described above. can.

In the ground improvement machine 200 of the above-mentioned reference invention , the rotation stop member 160 is simply a rod-shaped body that extends vertically, and the lower end portion or the portion near the lower end thereof rotates about the free rotation blade 30 that tries to rotate around the excavation shaft 10. However, the lower end of the rotation stop member 160 is attached to the lower end of the rotation stop member 160 like the rotation stop member 160 provided in another device (back ho) used in the above-mentioned method for manufacturing the improved solidified body. , As shown in FIG. 7, a bifurcated 165 is provided, and the free-rotating wing 30 is sandwiched between the bifurcated 165, so that the excavation shaft 10 is always rotated in the forward or reverse direction (rotational direction). The rotation of the free-rotating wing 30 may be stopped, or as shown in FIG. 8, a frame (for example, a square frame or a square frame or a square frame) that penetrates laterally to the lower end portion or the portion near the lower end portion of the rotation stop member 160 may be stopped. A hole) 167 may be provided, and the tip 35 of the free rotation blade 30 may be passed through the frame (hole). Further, in the above example, a pair of left and right free rotation blades 30 and 30 are used at the same height, and one of the blades is stopped by the rotation stop member 160. However, as shown in the modified example of FIG. 13, FIG. 9 shows. In the excavation mixing and stirring means shown, the portion near the lower end of one rotation stop member 160 is branched into two, and the rotation of the free rotation blades (both wings) 30 and 30 is stopped at each branch portion 169 and 169. You may do it.

The ground improvement machine 200 of the above-mentioned reference invention exemplifies the one without a stirring blade, but in this ground improvement machine 200 as well, the excavation shaft 10 is located above the rotary free blade 30 and the like as described above. Separately, a stirring blade may be provided, or a plurality of free rotation blades 30 may be provided on the upper and lower sides. In the case of providing in this way, the length of the free rotation blade 30 and the excavation of the rotation stop member 160 so that the rotation of the free rotation blade 30 can be stopped at a predetermined portion of the rotation stop member 160. Set the position inside the diameter circle Ke.

The present invention is not limited to the above-mentioned contents, and can be variously modified and embodied without departing from the gist thereof. The excavation shaft, the excavation blade, and the free rotation of the excavation shaft, the excavation blade, and the excavation mixing and stirring means in the ground improvement machine used in the method for manufacturing the improved consolidated body according to the first aspect of the invention and the above-mentioned ground improvement machine of the reference invention 1 described above. The specific shape and structure of the wing may be appropriately adjusted according to the soil quality of the ground to be improved, the required improvement quality, and the like. Further, as described above, the same applies to the presence or absence of the stirring blade. The number of free-rotating blades, stirring blades, and the like may be appropriately adjusted according to the soil quality of the ground to be improved, the required improved quality, and the like. In either case, the rotation stop member may be used to set an appropriate shape and structure so that the rotation of the free rotation blade can be stopped. That is, the rotation stopper member acts as a rotation stopper that can stop the rotation of the free-rotating blade that will be rotated by the rotational power of the excavated soil or the like that tries to rotate together with the excavation axis at the predetermined portion. , It may be set with an appropriate configuration.

10 Excavation shaft 20 Excavation wing 30 Rotating free wing 35 Tip of rotating free wing 100,200 Ground improvement machine 150 Another device 160 Rotation stop member G Ground Ke Excavation diameter circle

Claims (1)

As excavation mixing and stirring means for the ground, an excavation shaft that rotates around the vertical axis and moves up and down, an excavation blade provided near the lower end or the vicinity of the lower end of the excavation shaft so as to rotate with the excavation shaft, and the excavation blade. Using a ground improvement machine equipped with a free-rotating wing provided so as to be free to rotate and project laterally with respect to the excavation axis at a predetermined position above the excavation axis.
The solidifying agent is supplied into the excavated soil excavated while excavating the ground to a predetermined depth with the rotating excavation blade by rotating the excavation shaft to move downward, and the solidifying agent and the excavated soil are combined. In the method for producing an improved consolidated body, which forms an improved consolidated body in the soil through a mixing and stirring step of mixing and stirring.
The free-rotating wing has a length whose tip does not protrude outside the excavation diameter circle, which is a circle drawn by the tip of the excavation wing in a plan view and rotation of the excavation axis.
A rotation stop member for stopping the rotation of the free rotation blade around the excavation axis in the mixing and stirring step is provided in a device different from the ground improvement machine so as to be movable up and down.
In the mixing and stirring step, the rotation stop member provided in the other device is penetrated into the excavated soil and is moved downward so as to correspond to the downward movement of the excavation shaft, and a predetermined portion of the rotation stop member is provided. A method for producing an improved solidified body, which comprises stopping the free rotation blade from rotating around the excavation axis.

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