JPH07207657A - Ground improvement machine - Google Patents

Abstract

(57) [Summary] [Structure] The excavation shaft 32 is provided with an excavation blade 33 and a stirring blade 34. The excavation shaft 32 is connected to a drive device and is rotatable left and right. A kneading device including an arm member 37 and a plate 38 is provided on the excavation shaft 32 above the stirring blade 34. The plate 38 is a curved plate whose entire surface abuts on the inner wall of the excavation hole 40 excavated by the excavation blade 33, and rotates in conjunction with the excavation shaft 32. [Effect] A kneading device is attached to the excavation shaft, and the surface of the inner wall of the cylindrical drill hole that is excavated by the excavation blade is kneaded by the kneading device to provide a solid surface on the surface portion. A layer is formed. Therefore, it is possible to prevent the filler material from being scattered outside the hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement machine that mechanically mixes excavated soil and a filling material (solidifying material) in a foundation work or the like to consolidate, more specifically, the shape and strength as designed. The present invention relates to a ground improvement machine for forming an improved body (cured body) having:

[0002]

2. Description of the Related Art A ground improvement machine for improving the ground is formed by rotating an excavation shaft provided with an excavation blade and a stirring blade by a predetermined excavation mechanism, and using a fluid passage provided in the excavation shaft during excavation or extraction. While filling a filler such as sodium silicate and cement milk, the filler and the excavated soil mass are forcibly stirred and solidified to form the improved body in the soil.

Such a conventional ground improvement machine is disclosed in Japanese Examined Patent Publication Sho 58-2.
It is disclosed in Japanese Patent No. 9374. As shown in FIG. 8, in the ground improvement machine 1, the excavation diameter Da of the excavation blade 3 is provided between the excavation blade 3 and the stirring blade 4 of the excavation shaft 2 and between the stirring blades 4.
A co-rotation preventing blade 5 having a larger diameter Db is provided with a co-rotation preventing device 7 rotatably attached to the excavation shaft 2 via a boss 6.

Further, Japanese Patent Publication No. 58-29375 discloses a ground improvement machine 11 shown in FIG. This ground improvement machine 11 has a cylindrical body 1 having a diameter substantially equal to the excavation diameter Da of the excavation blade 13 above the excavation blade 13 provided on the excavation shaft 12.
4 and a resistance plate 15 protruding from the outer peripheral surface of the cylindrical body 14.
And a co-rotation preventing device 17 comprising a co-rotation preventing blade 16 extending from the inner peripheral surface of the cylindrical body 14 to the vicinity of the excavation shaft 12.
Is rotatably attached to the excavation shaft 12 via a boss 18 and an arm 19. Reference numeral 20 is a stirring blade.

As described above, the ground improvement machines 1 and 11 are provided with the co-rotation preventing devices 6 and 17 so that the excavated soil mass co-rotates with the cutting shafts 2 and 12 so that there is no excavation loss. . In these ground improvement machines 1 and 11, since the excavation blades 3 and 13 are rotated to advance into the soil, the ground improvement portion has a circular cross section.

[0006]

When carrying out ground improvement, the soil is excavated by using the above-mentioned ground improvement machine to form vertical holes. Then, the ground improvement machine is used to mix and stir the earth and sand and the filler in the drill hole.
Then, the wall of the hole collapses due to the earth and sand mixed and stirred in the hole and the filler, and as shown in FIG.
The hole wall of the vertical hole 22 actually built for 1 can be significantly disturbed.

As described above, since the earth and sand and the filler are mixed in the hole, the filler penetrates the wall of the hole of the vertical hole 22 and diffuses (dissipates) outside the hole. The strength of the improved product (cured product) may decrease.

Further, the degree of this dissipation varies depending on the site and within the same hole, depending on the nature of the soil and the stratum on which the improved body is built. Therefore, there may be a partial difference in the mixing concentration of the mixture of the earth and sand and the filler in the hole.

That is, not only the improved shape cannot take the shape as designed, but also the solidified material concentration cannot take the value as designed. As a result, the strength of the improved body may not satisfy the design requirement.

[0010]

The ground improvement machine of the present invention comprises:
An excavation shaft provided with an excavation blade and a stirring blade is excavated and extracted while rotating by a predetermined excavation mechanism, and in a ground improvement machine that mixes and agitates soil and a filler, in a radial direction with respect to the excavation axis. A plurality of extending arm members are attached, and at the tip of the arm member, a trowel-shaped plate that comes into contact with the inner peripheral surface of the excavation hole formed in the soil by the excavation blade is provided. is there.

According to a second aspect of the present invention, there is provided a ground improvement machine in which the excavation shaft provided with the excavation blade and the agitation blade is excavated and extracted while rotating by a predetermined excavation mechanism to mix and agitate the soil and the filler. In the improved machine, a rotary cylinder is externally fitted to the excavation shaft, and a plurality of arm members extending in the radial direction are attached to the rotary cylinder, and the tip of the arm member is attached to the soil by the excavation wing. It is characterized in that a trowel-shaped plate that comes into contact with the inner peripheral surface of the formed drill hole is provided.

[0012]

In the ground improvement machine of the present invention, the arm member and the trowel plate are attached to the excavation shaft,
The surface of the inner wall of the cylindrical excavation hole excavated by the excavation blade is kneaded by the arm member rotating with the excavation blade and the trowel plate, and a solid layer is formed on the surface portion. Therefore, the filler is prevented from penetrating into the pore wall and diffusing into the soil around the pores.

According to another aspect of the ground improvement machine of the present invention, the arm member and the trowel-shaped plate are attached to a rotary cylinder which is fitted onto the excavation shaft and is rotatably provided independently of the excavation shaft. The surface of the inner wall of the cylindrical drill hole to be drilled by the drill blade is kneaded by the arm member attached to the rotary cylinder and the trowel plate, and a solid layer is formed on the surface portion. It Therefore, the filler is prevented from penetrating into the pore wall and diffusing into the soil around the pores.

Further, since the excavation blade, the arm member and the trowel plate are independently rotatably provided, the excavation speed of the excavation hole and the kneading speed of the inner wall of the excavation hole are separately selected. It is possible to

[0015]

EXAMPLES Examples will be described below with reference to the drawings. FIG. 1 is a perspective view of the ground improvement machine according to the embodiment, and FIG. 2 is a plan view of the ground improvement machine of FIG. 1 showing the operation of the ground improvement machine.

In this ground improvement machine 31, an excavation blade 33 is attached near the tip of a hollow excavation shaft 32 which is connected to a drive device (not shown) and is rotatable in both forward and reverse directions. In addition, the excavation shaft 32 above the excavation blade 33
A stirring blade 34 is attached to.

The internal space 35 of the hollow excavating shaft 32 is
The drive device above and the opening 36 provided at the tip of the excavation shaft 32 communicate with each other. In this internal space 35,
The filling material is introduced from above, and the filling material is discharged from the opening 36 at a low pressure.

The excavation shaft 3 further above the mounting portion of the stirring blade 34.
Two arm members 37 are attached to 2. These four arm members 37 are mounted at 90 ° intervals in the same plane perpendicular to the excavation shaft 32. A trowel-shaped plate 38 is attached to the tip end side of the arm member 37.

The outer surface (front surface) of the plate 38 is a curved plate which is convexly curved outward in an arc shape in plan view, and its side end portion is on the side of the excavating shaft 32 (inner surface side). ) Is involved in. The arm member 37 is attached to the center of the back surface of the plate 38, and connects the excavation shaft 32 and the plate 38.

The distance from the axis of the excavation shaft 32 to the outer surface of the plate 38 is the distance from the axis of the excavation shaft 32 to the excavation blade 33.
Is equal to the distance to the tip of. The curvature of the outer surface of the plate 38 is set to be the same as the curvature of the circumference of the excavation circle formed by rotating the excavation blade 33. Therefore, as shown in FIG. 2, the surface of the plate 38 closely abuts the inner surface of the drill hole 40 drilled by the drill blade 33.

In order to carry out ground improvement by the ground improving machine 31 of the present embodiment thus constructed, first, the ground improving machine is moved to a predetermined position, and then the excavation shaft 32 is erected vertically on the ground. After that, the excavation shaft 32 is rotated and the excavation blade 3 is rotated.
Digging 3 into the ground. As the excavation blade 33 advances, the agitation blade 34 is also excavated underground, and the excavated soil is agitated. Further, the opening 3 provided at the tip of the excavation shaft 32
Fill material is discharged from 6 and mixed with the soil.

Next to the excavation blade 33 and the stirring blade 34, the plate 38 is excavated into the soil. As shown in FIG.
In the ground improvement machine 31 of the present embodiment, as the excavation shaft 32 rotates in the direction of arrow A, the excavation blade 33 and the plate 3 are rotated.
8 and the shaft 32 rotate in the same direction and at the same number of revolutions as the shaft 32.
Is formed.

As previously mentioned, the curved surface of plate 38 abuts the inner surface of borehole 40. Therefore, as the plate 38 rotates, the surface of the plate 38 strokes the inner surface of the excavation hole 40, and the earth and sand exposed on the surface of the inner surface wall of the excavation hole 40 is kneaded into the inner surface wall.
Therefore, the collapse of the inner wall of the excavation hole 40 is prevented.

This ground improvement machine 31 is pulled out to the ground when the ground up to a predetermined depth is improved.

FIG. 3 is a perspective view of a ground improvement machine according to another embodiment, and FIG. 4 is a plan view of the ground improvement machine of FIG. 3 showing the operation of the ground improvement machine.

This ground improvement machine 41 has a cylinder 42 on the excavation shaft 32 of the ground improvement machine 31 according to the embodiment shown in FIGS.
It is the one that is fitted. This cylinder 42 is the excavation shaft 32.
From above to near the upper part of the stirring blade 34.
It is movably fitted over. The cylinder 42 is connected to a drive device (not shown) different from the drive device for the excavation shaft 32 above the cylinder 42. Therefore, the excavation shaft 32 and the cylinder 42 can be independently rotated.

The plate 38 is attached to the cylinder 42 via an arm member 39. Also in the ground improvement machine 41 according to this embodiment, the configuration of the plate 38 and the attachment dimension of the plate 38 to the excavation shaft 32 are provided similarly to the ground improvement machine 31 according to the previous embodiment. Therefore, the surface of the plate 38 is in close contact with the inner wall of the drill hole 40.

Since the other construction is the same as that of the ground improvement machine of the embodiment shown in FIGS. 1 and 2, the same members and members having the same functions are designated by the same reference numerals and the description thereof will be omitted. .

According to the ground improvement machine 41 of this embodiment, the fourth
As shown in the figure, the rotation A of the excavation shaft 32 and the excavation blade 33
And the rotation B of the cylinder 42 and the plate 38 can be set independently. Therefore, even when excavating in a fragile stratum such as gravel or the like, the rotation speed of the plate 38 (kneading speed) is set to the rotation speed of the excavation blade 33 (excavation speed) so that the inner wall of the excavation hole 40 does not collapse. It can be dropped and excavated sufficiently.

In the ground improvement machines 31 and 41 of the above-mentioned embodiment, the number of the plates 38 is four, but other numbers may be used if they are arranged at equal intervals on the circumference.

Further, in the following, another structural example of the arm member for connecting the excavation shaft and the plate will be described with reference to FIGS.
It will be described with reference to the drawings. FIG. 5 is a vertical cross-sectional view showing a state in which the excavation shaft and the plate are connected by the arm member.

The arm member 45 is composed of a fixed arm 46 standing upright from the excavation shaft 32, a movable arm 47 standing upright from the back surface of the plate 38, and a spring 48. The fixed arm 46 is provided with an opening 49, and the leg portion 50 of the movable arm 47 is inserted into the opening 49. A spring 48 is housed inside the opening 49, and the movable arm 47 is provided so as to be movable back and forth with respect to the fixed arm 46.

The length of this arm member 45 is the same as that of the excavation shaft 32.
The distance from the excavation axis to the surface of the plate 38 is set to be slightly longer than the radius of the excavation hole 40 excavated by the excavation blade 33. Reference numeral 51 indicates the opening 49.
It is a sealing member that prevents intrusion of earth and sand into the interior.

In the ground improvement machine for excavating the excavation hole 40 with the arm member 45 thus constructed, the surface of the plate 38 springs the inner wall of the excavation hole 40 with the spring 48.
It is provided so as to be pressed from the inside by the urging force of. Therefore, the inner wall of the excavation hole 40 can be kneaded more reliably.

Still another structural example of the arm member will be described with reference to FIG. FIG. 6 is a vertical cross-sectional view showing a state in which the excavation shaft and the plate are connected by the arm member.

This arm member 52 has the same structure as the arm member 45 of FIG. 5 described above, and the leg portion 5 of the movable arm 47 is inserted into the opening 54 of the fixed arm 53 provided on the excavation shaft 32.
0 is inserted and inserted. A hydraulic pipe 55 arranged in the internal space 35 of the excavation shaft 32 is connected to the inner portion of the opening 54. This hydraulic pipe 55
Is connected to a hydraulic pump (not shown) above the excavation shaft 32.

Therefore, the inner part of the opening 55 formed by the opening 54 and the leg portion 50 fitted in the opening 54 serves as a pressure chamber 56 into which the hydraulic pressure of the hydraulic pump is introduced. Also,
Due to the pressure in the pressure chamber 56, the fixed arm 53
On the other hand, a movable arm 47 is provided so as to be able to move forward and backward.

In the other constructions of FIG. 6, members having the same or similar functions as those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted.

In the ground improvement machine for excavating the excavation hole 40 with the arm member 52 thus constructed, the pressure in the pressure chamber 56 is reduced and the arm member 52 is contracted in a short state. Is drilled. Next, after the plate 38 is dug into the hole 40, the pressure chamber 5
The pressure of 6 is increased to slightly extend the arm member 52, and the inner wall of the excavation hole 40 is pressed by the plate 38 which is displaced outward, so that the inner wall is kneaded.

When the excavation is completed and the earth and sand and the filler are mixed in the excavation hole 40, the ground improvement machine is lifted to the ground. At this time, the pressure in the pressure chamber 56 is reduced again, and the plate 38 is pulled up from the excavation hole 40 together with the excavation shaft 32 while being separated from the inner wall of the excavation hole 40.

According to the ground improvement machine having the arm member 52, the inner wall of the excavation hole 40 can be kneaded more reliably, and the plate 3 in the excavation hole 40 can be kneaded.
8 is inserted and the plate 38 is pulled up from the excavation hole 40, the arm member 52 can be contracted and the plate 38 can be kept away from the inner wall of the excavation hole 40. Do not collapse the inner wall of the entrance of the.

FIG. 7 shows a ground improvement machine according to still another embodiment. In this ground improvement machine 61, the excavation shaft 32
The large plate 6 is attached to the tip of the stirring blade 62 which is erected from
3 is provided. That is, in the ground improvement machine 61, the stirring blade 62 also serves as an arm member that connects the excavation shaft 32 and the plate 63.

Therefore, since the ground improving machine 61 has a simplified structure, it is possible to reduce the weight of the ground improving machine 61 and to keep the production cost low.

Also in the embodiment shown in FIG. 7, the same members and members having the same function as those of the embodiments of FIGS. 1, 2, 3, 4, 5, and 6 described above. Are denoted by the same reference numerals, and description thereof will be omitted.

[0045]

In the ground improvement machine of the present invention, the surface of the inner wall of the cylindrical excavation hole is kneaded by the arm member rotating with the excavation shaft and the trowel plate, and the surface portion is solidly packed. Layers are formed. Therefore, it is possible to prevent the filler material from being scattered outside the hole.

In the ground improvement machine of claim 2, the surface of the inner wall of the cylindrical excavation hole is kneaded by the arm member attached to the rotating cylinder and the trowel-shaped plate, and the surface portion is closely packed. Layers are formed. Therefore, the filler is prevented from penetrating into the pore wall and diffusing into the soil around the pores.

Further, since the excavation speed of the excavation hole and the kneading speed of the inner wall of the excavation hole can be separately selected, the kneading can be surely performed even if the inner wall is fragile.

[Brief description of drawings]

FIG. 1 is a perspective view of a ground improvement machine according to an embodiment of the present invention.

FIG. 2 is a plan view showing an operation of the ground improvement machine of FIG.

FIG. 3 is a perspective view of a ground improvement machine according to another embodiment.

FIG. 4 is a plan view showing an operation of the ground improvement machine of FIG.

FIG. 5 is a vertical sectional view showing a structural example of an arm member.

FIG. 6 is a vertical cross-sectional view showing another structural example of the arm member.

FIG. 7 is a perspective view of a ground improvement machine according to still another embodiment.

FIG. 8 is a cross-sectional view showing an excavation hole during excavation using a conventional ground improvement machine.

FIG. 9 is a cross-sectional view showing an excavation hole during excavation using another conventional ground improvement machine.

FIG. 10 is a cross-sectional view showing an example of excavation of an excavation hole using a conventional ground improvement machine.

[Explanation of symbols]

 1,11,31,41,61 Ground improvement machine 2,12,32 Excavation axis 3,13,33 Excavation blade 4,20,34,62 Stirring blade 5,16 Co-rotation prevention blade 6,18 Boss 7,17 Anti-rotation device 37, 39, 45, 52 Arm member 38, 63 Plate 46, 53 Fixed arm 47 Movable arm 48 Spring 56 Pressure chamber

Claims (2)

[Claims] 1. A ground improvement machine for advancing and extracting while excavating an excavating shaft provided with excavating blades and a stirring blade while rotating by a predetermined excavating mechanism to mix and stir the soil and the filling material. A plurality of arm members extending in a radial direction are attached to the arm member, and a trowel-shaped plate that comes into contact with the inner peripheral surface of the excavation hole formed in the soil by the excavation blade is provided at the tip of the arm member. A characteristic ground improvement machine. 2. A ground improvement machine for advancing and withdrawing an excavation shaft provided with excavation blades and a stirring blade while rotating by a predetermined excavation mechanism to mix and agitate soil and a filling material. A rotary cylinder is fitted on the outer circumference of the rotary cylinder. A plurality of arm members extending in the radial direction are attached to the rotary cylinder, and at the tip of the arm member, the inside of the excavation hole formed in the soil by the excavation blades is attached. A ground improvement machine, which is provided with a trowel plate that contacts the peripheral surface.