JP2001115445A - Excavated soil mixing and stirring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixing and stirring device to efficiently improve the ground even when the excavation resistance is increased in a soft ground containing gravel and stone blocks. SOLUTION: An excavation blade 11 provided on a lower end of an excavation shaft 1 is of a sweepback blade shape, and the sweepback angle θ1 is, for example, 30 deg.. The excavation shaft 1 is turned, the excavation of the ground is started by the excavation blade 11, and as penetration and boring are advanced, the resistance is small since the excavation blade 11 is of the sweepback blade shape of 30 deg.. Thus, excavation and stirring can be easily and efficiently achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixing and stirring apparatus for excavated soil, and more particularly, to excavating soft ground into one or more excavation shafts in a columnar shape in civil engineering and construction (construction) foundation work. A lime-based or cement-based slurry-type solidifying agent (hereinafter also simply referred to as a solidifying agent) is discharged while mixing and stirring, and the solidifying agent is mixed with the excavated soil, stirred and solidified to improve the ground. The present invention relates to a device for mixing and stirring excavated soil (hereinafter, also simply referred to as a device) used for excavation.

[0002]

2. Description of the Related Art Conventionally, this type of excavated soil mixing and stirring apparatus has a drilling blade provided with a drilling claw at the lower end of a drilling shaft, and one or more stirring blades provided thereon. ing. If necessary, a diameter (length) larger than the outer diameter (digging diameter) of the excavating blade is provided between the excavating blade provided on the excavating shaft and the stirring blade or between the plurality of stirring blades. There is also provided an anti-rotation device in which a rotation prevention wing is rotatably mounted on an excavation shaft via a boss to prevent co-rotation of excavated soil during excavation.

[0003] By the way, the drilling wing in such an apparatus is usually provided so as to be perpendicular to the drilling axis, that is, substantially horizontal. In addition, the stirring blade and the co-rotation prevention blade provided on the excavation blade are generally provided substantially horizontally in the same manner as the excavation blade in terms of the stirring efficiency.

In such a conventional apparatus, since the excavating wing is substantially horizontal, an excavating claw (hereinafter also referred to as a claw) provided below the excavating wing is rotated downward in a fixed direction of the excavating shaft. It is normal that it is inclined to cut into the ground (with a rake angle).

[0005]

However, the prior art has the following problems. That is, the ground to be improved is basically soft ground, but its geology varies. For example, excavation is fundamentally difficult in the case of geology including gravel and stone blocks. This is because, in the prior art, since the excavation wing is substantially horizontal, resistance when the excavation wing enters the ground, that is, penetration resistance (excavation resistance) is large. For this reason, there was a problem that the traveling speed of the excavation wing into the ground became slow, construction took time, and construction efficiency was extremely poor. Even if it can penetrate to a certain depth, in the case of gravel, if it collides with the contained stone, it may even be impossible to excavate further. In particular, if it hits a stone block, it is impossible to penetrate it further, and it is difficult to improve it to deep layers. For this reason, the construction may be difficult or impossible with the conventional excavator, and the excavation position may have to be changed during the construction.

[0006] Such a problem may occur not only in the gravel layer but also in the hard clay layer due to the high excavation resistance. Further, in the case of such a geology, the biteability is poor, and therefore, when the excavation diameter is large, a large power is required, and the heavy equipment is enlarged. in this way,
With conventional equipment, sufficient ground improvement cannot be achieved as a result,
This caused serious problems such as land subsidence after the building was built.

The present invention has been devised in view of the above problems of the conventional excavated soil mixing and stirring apparatus,
It is an object of the present invention to provide a mixing and stirring device for excavated soil that can efficiently improve the ground even when the excavation resistance is increased in soft ground including gravel or stone blocks.

[0008]

In order to achieve the above object, a mixing and stirring apparatus for excavated soil according to the present invention is characterized in that the excavating wing has a swept wing shape and the swept angle is 10 degrees or more. .

In the present invention, the swept wing shape refers to a shape in which the lower side (digging claw) of the digging wing 11 is located at the rear portion (upper end portion) of the digging shaft 1 as it goes toward the tip, as shown in FIG. Say. In other words, it refers to a shape in which the excavation wing extends radially outward of the excavation axis so that the tip of the excavation wing is located above the vertical (horizontal direction) with respect to the excavation axis. The receding angle is an angle indicating the degree of receding, and as shown in FIG. 1, a line drawn in the horizontal direction perpendicular to the excavation axis 1 when the mixing and stirring device 101 is viewed from the front (side surface). It refers to an angle θ1 formed with a line drawn radially outward along the lower side of the excavation wing 11. As described above, in the present invention, since the excavation wing has a swept wing shape and the swept angle is 10 degrees or more, even in the case of gravel or a hard clay layer, it is easy to penetrate and excavate into the ground, thus improving workability. I do. However, the sweep angle of the excavation wing is preferably 20 degrees or more. In any case, the receding angle may be set to 60 degrees or less.

In any of the above means, the digging claw provided on the digging wing is formed so as to have a rake angle, that is, to have a rake angle, regardless of whether the digging axis is rotated forward or backward. Good to be.

The rake angle of the excavation claw means that the excavation claw is inclined so as to scoop and excavate excavated soil according to the rotation (excavation) when the excavation axis moves down and the excavation wing rotates. Say. More specifically, as shown in FIG. 3, a line drawn vertically upward from the tip of the excavating claws 13 and 14 and a line drawn along the upper surface from the tip on the upper surface side of the excavating claws 13 and 14 Means that the angle θ2 of the space formed is an acute angle.

In the present invention, if the excavating claw provided on the excavating wing is formed so as to have a rake angle regardless of whether the excavating shaft is rotated in the forward or reverse direction, the excavator rotates in either the forward or reverse rotational direction. Can be excavated. Therefore, for example, when the excavation claw collides with a stone in the excavated soil during normal rotation and escapes from the stone and cannot be excavated, by reversing, the excavation claw on the reverse rotation side scoops the stone. Because it can be moved. In other words, when there is no rake angle, or when there is only one rake angle so that the excavated soil can be scooped only when rotating in one direction, the excavation claw It is effective as a countermeasure in the event that a person escapes by hitting a part of the. In other words, even if the excavation claw does not have a rake angle, the stone cannot be scooped even if it is rotated in the opposite direction. Cannot scoop. On the other hand, in the present invention, a positive rake angle can be obtained even by reverse rotation, so that the stone can be scooped.

[0013] In any of the above-mentioned means for mixing and stirring excavated soil, the stirring blade is provided above the excavation blade and on the excavation axis.
And an anti-corotating wing which is larger in diameter than the excavating wing and is rotatably mounted around the excavating axis, and the stirring wing and the co-rotating wing are preferably in the form of swept wings. In this case, it is preferable that the swept angle of the stirring blade and the co-rotation preventing blade be substantially the same as the swept angle of the excavating blade. The sweepback angle of the stirring blade and the co-rotation prevention blade is preferably in a range of ± 5 degrees with respect to the sweepback angle of the excavation blade.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mixing and stirring apparatus for excavated soil according to the present invention will be described in detail with reference to FIGS. However, the following embodiments are configured by joining steel components to each other by welding or the like. In the figure, 101 is a mixing and stirring device of the present embodiment, 1 is a substantially cylindrical (or hollow cylindrical) excavation shaft (rotation drive shaft), and a rotation drive means (not shown) provided above. The drilling wing 11 having a predetermined diameter is provided to protrude right and left slightly above the vicinity of the tip side (the lower end of the drilling shaft 1). .

The excavation wing 11 has a retreating wing shape whose tip (both ends) is located above a horizontal direction perpendicular to the excavation axis 1 and extends radially outward with a predetermined width (height). I have. However, in the present embodiment, the retreat angle θ1 of the excavating wing 11 is configured to be 30 degrees. And the drilling wing 1
A plurality of excavation claws 13 and 14 are arranged below 1 (lower edge). However, the claws 13 and 14 are arranged so as to be able to scoop the excavated soil regardless of whether the excavating shaft 1 rotates in the normal or reverse direction, when viewed from the end of the excavating wing 11 (cross section taken along line AA in FIG. 1). Each is inclined obliquely downward, and the amount of protrusion is the same for the left and right. The rake angle θ2 is 45 degrees in this embodiment.

In this embodiment, the anti-corotating wing 21 having a larger diameter than the digging wing 11 is provided on the digging wing 11 in a front view.
The receding angle θ1 is set to 30 degrees so as to be substantially parallel to 1. The anti-corotating wing 21 has a strip shape having a predetermined width. Although not shown in detail, a central tubular portion 23 is fitted over the excavating shaft 1 and the upper and lower The ring parts 5 and 6 are mounted so as to be rotatable around the axis G of the excavation shaft 1 while restricting the vertical movement thereof.

In this embodiment, on the anti-corotating wing 21,
A stirring blade 31 having a diameter slightly smaller than the diameter of the drilling blade 11 is provided. Note that the stirring blade 31 is also a strip-shaped member having a predetermined width.
It is formed so as to extend left and right from the excavation axis 1 so that 1 becomes 30 degrees. In addition, near the tip side of the excavation shaft 1,
A discharge port 1a for a slurry-like solidifying agent is provided, and the solidifying agent (not shown) is configured to be discharged from the pressure feed source into the excavated soil K through the inside (hollow portion) of the excavating shaft 1. .

Next, the operation and effect of the mixing and stirring device 101 of this embodiment will be described. Example device 1
In the case where the ground J is excavated with 01 and mixed and stirred, the operation is as follows. When the excavation shaft 1 enters the ground J while rotating to one side, the excavation wings 11 make the diameter D substantially the same as that.
Excavation starts at 1. At this time, since the excavation wing 11 has a swept wing shape in FIG. 1, the resistance when penetrating into the ground is small, so that the excavation wing 11 can easily penetrate even in the ground of a gravel or a hard clay layer, and the subsequent excavation becomes easy. .

In addition, in this embodiment, the excavating claws 13 and 14 are provided so that they can be excavated by either left or right rotation. Therefore, even when the excavation claw 13 is rotated clockwise and cannot excavate, the stone is scooped up by rotating in reverse. Can be moved. In other words, when the excavation claw 13 collides with a stone during normal rotation and escapes from the stone and cannot be excavated, it reverses,
This is because the excavation claw 14 on the reverse side can scoop and move the stone.

In the present embodiment, the ground J is excavated in a columnar shape with a diameter D1 substantially equal to the diameter of the excavation wing 11, and the co-rotation prevention wing 21 thereon hits the outer edge of the excavation diameter D1 and cuts. As it enters the ground, the co-rotation prevention wings 21 are restrained at their ends by the hard soil of the periphery, and when viewed in plan (as viewed from above), around the axis G of the excavation shaft 1. Will not rotate. Therefore, the excavation wing 1
Excavated soil K that moves so that it rotates together with 1 and stirring blade 31
The co-rotation prevention blade 21 prevents or separates the co-rotation, and under the condition, the excavated soil K is mixed and stirred. Further, as the excavation proceeds and the stirring blade 31 immediately above enters the excavated soil as shown in FIG. 1, the rotating cutting blade 11 and the stirring blade 3 are rotated.
1. The excavated soil K is mixed and stirred while the co-rotation is prevented by the co-rotation prevention blade 21 that does not rotate.

Thus, according to the apparatus 101 of the present embodiment, since the excavation wing 11 is given the angle θ1 as the sweepback angle, even when the excavation resistance of the portion to be improved is large,
Excavation and agitation are easily performed because the resistance associated with the penetration and excavation of the excavation wing 11 is small. That is, even in the case where the excavation resistance is increased in a relatively hard ground or a ground in which stones and rocks are mixed, the ground can be efficiently improved to a deep layer.
In addition, since the excavation resistance is reduced, it is possible to use a small amount of power, so that the size of heavy equipment can be reduced. In particular, in the present embodiment, not only the excavation blade 11 but also the co-rotation prevention blade 21 and the stirring blade 31 have the same sweepback angle θ.
Since the number 1 is added, not only the excavation resistance is reduced, but also the mixing and stirring are performed efficiently and efficiently because the space between them is parallel.

Here, as shown in FIG.
1. The anti-corotating blade 21 and the stirring blade 31 have a constant receding angle θ.
A test apparatus having 1 was manufactured by changing θ1 in a range of 0 to 60 degrees, and a predetermined excavation test was performed. However, the diameter of the excavation wing 11 was 600 mm, and in the test (excavation), excavation at a depth of 5 m was performed 5 times in a stable gravel layer. Then, the total time (seconds) required for excavation five times was divided by 25, and the time required for excavation per 1 m (excavation time) was measured. The results are as shown in Table 1. However, the time (seconds) in Table 1 is rounded off to the nearest second (digit).

[0023]

[Table 1]

As shown in Table 1, in the comparative example in which the sweepback angle θ1 is 0 ° and 5 °, the excavation time (time required for excavation per 1 m) was 810 seconds or more. If the range is more than 10 degrees, the time is short, less than 590 seconds. In particular, when the angle θ1 is 20 degrees or more, the excavation time can be remarkably reduced to 270 seconds or less. This proves that the drilling wing of the present invention has low resistance to intrusion into ground and excavation, and is easy to construct. When the receding angle is too large, the angle of the tapered taper at the bottom of the improved column becomes too small, resulting in insufficient strength due to thinning of the lower end of the improved column. In addition, the length of the excavation wing becomes too long, and the resistance in the excavated soil increases. In consideration of these points, it is appropriate that the receding angle θ1 is set to 60 degrees or less.

In the above embodiment, not only the excavation wing 11 is formed into a swept wing shape but also the excavation claws 13 and 4 are provided so as to be able to excavate in either forward or reverse rotation. In this way, the removal of stones in excavated soil can be dealt with. However, when excavating the clay layer (ground improvement), the excavation claw may be provided so that there is a rake angle θ2 only at the time of normal rotation, or there is no rake angle (for example, a form extending directly below). The excavation claw may be used.

In the above embodiment, the apparatus is provided with the anti-corotating blade 21 and the stirring blade 31. However, in the present invention, the anti-corotating blade may be omitted. This is because it is unnecessary when the soil is relatively difficult to rotate. Further, even when the anti-corotating blade and the stirring blade are provided, it is not always necessary to form the swept blade as in the case of the excavation blade. However, if these also have swept wing shapes, the spacing between the wings can be reduced,
Stirring is performed efficiently and efficiently. Further, in the case where the co-rotation prevention blades and the stirring blades are provided, the number of each blade may be appropriately set according to the soil quality, the digging diameter or the digging depth.

Further, in the above-described embodiment, the excavating blade 11, the co-rotation preventing blade 21, and the stirring blade 31 are all provided so as to extend to the left and right of the excavating shaft 1. However, this is done in plan view, at equal angular intervals, or at irregular angles. Three or more radial directions may be provided at intervals. Further, in the above-described embodiment, the case where the excavation wing 11, the co-rotation prevention wing 21, and the stirring wing 31 are both provided as a pair at the same height portion of the digging shaft 1 in a double wing state is illustrated. It may be provided so as to have both wings, or may be provided with one wing. Further, in the above-described embodiment, the excavating blade 11, the co-rotation preventing blade 21 and the stirring blade 31 are both formed in a linear shape in a plan view, but may be formed in an arc shape or a V shape. In the above embodiment, 1
Although the embodiment embodied in the excavation axis is illustrated, the present invention can also be embodied in each excavation axis in a mixing and stirring apparatus for excavated soil provided with a plurality of excavation axes.

[0028]

As is apparent from the above description, according to the apparatus of the present invention, the excavation wing has a swept wing shape, and the swept angle is appropriately set. Since the resistance at the time of intrusion or excavation can be reduced, the workability of ground improvement work can be enhanced. In addition, since the excavation resistance is reduced, miniaturization of heavy equipment is also expected.

[Brief description of the drawings]

FIG. 1 is a front view (side view) showing a schematic configuration of an embodiment of a mixing and stirring apparatus for excavated soil according to the present invention.

FIG. 2 is a perspective view of one excavation wing portion of FIG. 1;

FIG. 3 is an enlarged cross-sectional view taken along line AA of the excavation wing in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drilling axis 11 Drilling wing 13 Drilling claw 21 Anti-rotating wing 31 Stirring wing θ1 Sweep angle θ2 Rake angle G Axis of drilling axis

Claims (6)

[Claims] 1. A mixing and stirring apparatus for excavated soil, wherein the excavating wing has a swept wing shape and the swept angle is 10 degrees or more. 2. A mixing and stirring device for excavated soil, wherein the excavating wing has a swept wing shape, and the swept angle is 20 degrees or more. 3. The mixing and stirring apparatus for excavated soil according to claim 1, wherein the receding angle is 60 degrees or less. 4. The excavation claw provided on the excavation wing is formed such that a rake angle is formed regardless of whether the excavation shaft is rotated forward or backward. A mixing and stirring device for excavated soil according to the above. 5. The co-rotation preventive device according to claim 1, 2, 3 or 4, wherein a stirring blade is provided on the excavation shaft above the excavation wing, and a rotating blade is installed around the excavation shaft with a diameter larger than the excavation wing. A mixing and stirring apparatus for excavated soil, comprising a blade, wherein the stirring blade and the co-rotation prevention blade are formed in a retreating blade shape. 6. The apparatus for mixing and stirring excavated soil according to claim 5, wherein a retreat angle of the stirring blade and the co-rotation preventing blade is substantially the same as a retreat angle of the excavating blade.