JPH07109091B2 - Ground improvement device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement apparatus whose main purpose is to construct a strong and optimal ground layer in a ground such as a building by an almost soil-free and vibration-free construction method.

[0002]

2. Description of the Related Art Construction devices of various shapes have been developed as conventional ground improvement devices, but these mechanisms merely excavate a pile hole for foundation pile driving in the ground, for example at the tip of the head. It is composed of an excavating blade for excavating the underground and screw blades for excavating the excavated soil on the ground.

However, since most of the construction devices of this type excavate the ground by rotating the tip excavation blade as described above, the excavation blade disturbs excavation of the ground, of course, and especially During the excavation work, the peripheral wall of the hole collapsed, which fell into the hole and caused serious obstacles to the subsequent work.
In addition, there are various drawbacks such as excavation of the excavated soil by the action of the screw blades, which is accumulated on the ground, and a considerable amount of labor and cost are required for the work such as the soil removal treatment.

In order to solve such a drawback, the present inventor has previously shown the excavator shown in FIG. 1 (Japanese Patent Application No. 3-3818).
9), that is, in the auger head A having the cutting blade B and the disturbing blade C at the tip, a conical shaped soil surface D is formed on the upper portion of the disturbing blade C and the longitudinally crossing the soil surface D. We have developed a device that is provided with a concave groove E having a substantially triangular shape. The device temporarily accumulates the excavated earth and sand in the recessed groove E during the underground excavation,
With the rotation of the head, the retained earth and sand are gradually extruded in the outer peripheral direction, and the pitting action of the concave groove surface is used to press the holes around the holes to create a strong pile hole around the holes. In comparison with the conventional method of simply consolidating the circumferential surface of the hole, the hole wall is pressed more firmly and securely to dig into the ground, and the soil around the hole collapses during the drilling operation. It is a convenient non-burning earth digging device that does not have the fear of and that there is almost no discharge to the ground.

In the case of such a device, on the other hand, while having the above-mentioned advantages, the excavated earth and sand is temporarily stored in the recessed groove E having a vertical cross section and a substantially triangular cross section, and this is accompanied by the rotation of the head. It was found that since the sand and sand are pushed out and pressed in the outer peripheral direction, a strong pressing can be obtained, but a considerable resistance is generated at the time of rotation and a large amount of energy is required.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and it is possible to reduce the resistance of any soft-hard ground layer and to make a pile strong on a predetermined ground with very little energy. Its main purpose is to provide a ground improvement device capable of surely and easily constructing a hole and making a hole with almost no soil.

[0007]

As a means for achieving the above-mentioned object, the ground improvement apparatus according to the present invention is provided with an excavating blade 2 having an appropriate shape at the tip of an auger head 1 and a number above the excavating blade 2. The disturbing blade 3 is attached and the disturbing blade 3 is attached.
A slender conical soil surface 4 of a certain length is formed on the upper part of the slant, and a deformed triangular spiral groove 5 having an acute surface c and a gently sloping surface b is formed in the concave groove in the slender conical soil surface 4. It features a structure attached to the non-rotational direction.

[0008]

Next, the construction example of the device will be described. First, the device is set on a pile driver and placed on a predetermined ground, and then the auger is driven and rotated to rotate the tip excavation blade 2 to a predetermined depth. Dig up to. At the same time as the above-mentioned excavation, the elongated conical shaped soil surface 4 coaxial with the excavating blade 2 is used to gradually press the circumferential surface of the hole to form a column hole of a predetermined length in the ground. At the time of excavation, the slanted conical soil surface 4 is attached in a non-rotational direction to the slanted spiral groove 5, that is, the rotating action of the acute-angled surface c cuts and widens the hole periphery, and at the same time, the cutting sand is gently slanted to one By rotating the surface b, the peripheral wall of the hole is firmly clamped while expanding and compressing to the periphery of the hole, and a strong hole wall without collapse can be easily and surely obtained.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Reference numeral 1 denotes an auger head formed by forming an overall shape into a substantially vertically long conical shape.
Install. Further, just above the excavating blade 2, several disturbing blades 3 having a blade length substantially the same as the diameter a of the auger head 1 are arranged at appropriate intervals to excavate during excavation. It also has the function of stirring and kneading mortar milk that can be added at the same time that the soil is disturbed. An elongated conical shaped soil surface 4 having a gentle inclination angle is formed on the upper portion of the disturbing blade 3 due to the relationship with the excavation geology, and an inclined shape with respect to the non-rotating direction is formed at an appropriate place such as the upper portion of the soil surface 4. The spiral groove 5 is provided with one or several recesses.

As shown in FIG. 3, the spiral groove 5 is formed in a substantially triangular shape with the inner surface of the concave groove having a gentle slope b in the rotational direction and the acute angle surface c in the non-rotating direction. ing. Although not shown in the figure, the auger head 1 has a structure in which a cement milk injection hole and a cement milk feed pipe are attached to the tip, and a tip drilling blade 2 and a drilling blade 3 are provided. It is also possible to detachably connect the tip head below the elongated conical shaped soil portion without integrating it with the auger head 1.

[0011]

According to the present invention, the elongated conical shaped soil surface 4 is formed on the upper part of the auger head 1 having the tip digging blade 2 and the disturbing blade 3 as described above, and the soil surface 4 is not formed. Since the spiral groove 5 is additionally formed in the direction of rotation, it has the smallest resistance during excavation as compared with the previously developed recessed groove E having a generally triangular cross section with a vertical split. It is possible to more firmly and surely compress the hole circumference and to easily and reliably dig a strong pile hole in the ground. That is, according to the present invention, the gently sloped surface b and the acute angle surface c in the spiral groove 5 during the above-described excavation.
Since the hole wall is surely cut by the action of the reverse spiral due to and at the same time, the cutting sand is naturally released in the outer peripheral direction, the sloping surface b acts to press the sloping surface. Unlike the soil device, there is almost no strong resistance load generated during excavation, so that the hole periphery can be clamped more firmly and reliably. Further, since the hole wall is pressed at the same time as the excavation, there is no concern about collapse of the hole circumference during the work, and the excavated earth and sand is reliably pressed to the hole circumference, and the amount of soil discharged to the ground is also high. It can be said to be a great invention not only for waste disposal work, but also for economical reasons such as the fact that friction resistance during excavation is small and the energy used can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a front view of a ground improvement device excavation device developed earlier,

FIG. 2 is a front view of the ground improvement device according to the present invention.

FIG. 3 Same as above, right side view

FIG. 4 is a transverse cross section of a main part of the same.

[Explanation of symbols] 3 Disturbing blade 4 Elongated conical soil surface 5 Helical groove

Claims (2)

[Claims] Claim: What is claimed is: 1. An auger blade having an appropriate shape is attached to the tip of the auger head, several disturbing blades are attached to the upper part of the agitating blade, and an elongated conical shaped soil surface of a constant length is provided on the agitator blade. And a spiral groove having a cutting and soil portion on the elongated conical soil surface is provided with one or several lines in the non-rotational direction. 2. The recessed portion of the inner surface on the upper part of the elongated conical compacted soil surface according to claim 1 has a gentle inclined surface b with respect to the rotating direction and an acute angle surface c with respect to the non-rotating direction. A ground improvement device having a substantially deformed triangular spiral groove 5 formed therein.