JPH0791933B2 - 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 device whose main purpose is to easily and surely construct a strong and optimum ground layer in a ground such as a building by a low-resistance non-removal earthing method.

[0002]

2. Description of the Related Art As a conventional ground improvement device, construction devices of various shapes have been developed and used, but most of them are for the purpose of digging a pile hole for driving a foundation pile into the ground.

That is, below the auger rod, there are provided a cutting blade for excavating the tip ground and several disturbing blades for excavating the ground, and further, a screw blade is attached to the shaft portion of the auger rod for excavating soil. It has the function of landing on the ground. However, since the conventional excavation device is based on the above, while the drill hole is easily constructed along with the ground excavation, at the time of the drilling work, the hole circumferential wall is dug into these excavated soils and the excavated soil collapses. It has the drawback of being buried in the bottom of the hole,
Not only causes serious troubles in the work after fire, but also excavates the excavated soil by the action of the following screw blades,
It takes a lot of labor and cost for the enormous amount of soil disposal such as the accumulation on the ground.

In view of the difficulty of the soil removal treatment, the excavated soil is not excavated on the ground at the same time as the excavation of the soil, but the excavated soil is pressed to the periphery of the excavated hole to form a strong pile without collapse. As for the technique for obtaining the holes, several examples such as Japanese Patent Nos. 1316177 and 1153361 are known. That is, these techniques form the peripheral edge of the screw blade attached to the auger rod on a thick soil surface, and excavate the excavated soil at the same time as the excavation progresses, and at the same time, firmly and securely clamp the hole wall. ,
There is no concern about collapse of the perimeter soil, and there is almost no soil discharge to the ground.

In the case of such a device, on the other hand, although it has the above-mentioned advantages, since it tries to press the peripheral wall of the hole with the rotation of the auger rod, a considerable resistance is naturally generated during the rotation, and the energy is burdened. It is questionable whether or not the whole pile hole is solidified due to the soft and hard geology at the time of excavation, and it is difficult to make a vertical hole.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to fundamentally solve the above-mentioned problems, and is of any soft ground layer, the resistance is reduced and the total length in the vertical direction is reduced with very little energy. Its main purpose is to securely fasten the circumferential wall of the hole and to provide a soil improvement device that is completely free of 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 its tip, and a conical surface 4 is provided on the upper portion of the excavating blade 2. And an auger rod 1 having a certain length is continuously provided on the upper part of an auger head 1 having a plurality of disturbing blades 3 attached to the conical surface 4, and the auger rod 5 Several triangular protrusions 6, 6, 6 on the shaft surface
The base is formed so as to project in a spiral shape over the entire vertical length of the shaft, and the diameter A of the cutting edge of the excavating blade 2 and the disturbing blade 3 is approximately the same as the diameter B of the triangular raised protrusion. It features an improved device.

[0008]

Next, the construction example of the apparatus will be described. First, the auger head 1 having the above structure is integrally connected to the lower end of the auger rod 5, and the entire apparatus is built on a predetermined ground by a pile driver. By driving and rotating the device, the excavating blade 2 rotates to excavate the tip of the ground, and at the same time, the conical surface 4 coaxial with the excavating blade 2 and the disturbing blade 3 disturb and spread the perimeter soil. A pillar hole of a predetermined length is bored in the ground. At the time of such excavation, the pile perimeter is expanded at the tips of the triangular raised protrusions 6 by the rotation of the loose spiral triangular raised protrusions 6, 6, 6 formed on the surface of the auger rod 5, and at the same time each soil surface a is pierced. The peripheral wall soil has an effect like a trowel surface, and the excavated soil can be pressed against the peripheral wall of the hole, and the pile hole having a strong hole wall can be surely constructed in the ground. Moreover, since there is almost no concern about excavation of excavated soil due to the soil compaction effect, it is possible to easily and surely find a construction method of completely non-discharging soil.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings, in which 1 is an auger head provided with a cutting blade 2 of an appropriate shape at the lower end thereof, and the shape above the head is a conical shape of a substantially vertically elongated cone Formed on the surface 4 and several disturbing blades 3,
3 is arranged at appropriate intervals to have a function of disturbing the excavated soil at the time of excavation and at the same time well stirring and kneading the mortar milk to be put into the pile hole. The auger rod 5 comprises a rod shaft having an appropriate length and a plurality of triangular protrusions 6, 6, 6 formed on the peripheral surface of the shaft around the shaft in the form of a loose spiral projecting above and below the shaft. As shown in the drawing, the raised surface of the triangular raised convex portion 6 is formed on the swollen curved surface compacted soil surfaces a, a, and has a trowel surface action of compacting the soil on the hole circumferential wall during rotation.

Further, the diameter A of the cutting edge of the cutting blade 2 and the disturbing blade 3 is formed to be substantially the same as the diameter B of the tip end of the triangular raised protrusion 6. Depending on the case, a milk pouring pipe 8 which is communicated with the cement milk injection hole 7 opened at the tip of the auger head 1 is inserted in the shaft portion of the auger rod 5.

[0011]

According to the present invention, several triangular raised protrusions 6, 6, 6 are additionally formed on the upper part of the auger head 1 having the tip cutting blade 2 and the disturbing blade 3 on the lower side as described above. Therefore, not only excavating the ground but also expanding and tightening the hole peripheral wall by the conical surface 4 formed on the upper part of the auger head 1 in association with the excavation rotation, and further follows the hole peripheral wall that can be tightened. It is possible to more easily perform the vertical pile holes that are more tightly pressed on the soil concavities a, a, a of the triangular raised protrusions 6, 6, and 6 and do not worry about collapse. In particular, in the present invention, the triangular raised projections 6, 6, 6 are formed in a spiral shape over the entire length of the axial surface of the auger rod 5 so that the hole circumference can be smoothly and surely compressed with the shape having the least resistance. Therefore, there is an effect that a stronger pile hole can be easily dug in the ground in a short time.

Further, as described in claim 2, since the cutting edge diameter A of the cutting blade 2 and the disturbing blade 4 is formed to be substantially the same as the tip end diameter B of the triangular raised protrusion 6, the ground tip is excavated. Since the hole diameter gap of the auger rod 5 that follows the hole diameter is reduced, vibration in the lateral direction in the pile hole is suppressed, and the resistance load generated during excavation is reduced to compress more soil. Therefore, it is possible to easily obtain a strong compaction layer on the peripheral wall of the hole, and since the excavated soil is surely clamped to the hole periphery, there is almost no earth discharge, and there is almost no problem in the conventional earth removal treatment work. It also has the effect of being able to greatly reduce energy consumption. It is also possible to construct a vertically long vertical pile hole by connecting the auger rod 5.

[Brief description of drawings]

FIG. 1 is a front view of a ground improvement device according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the same.

[Explanation of symbols]

 1 Auger head 3 Disturbing blade 5 Auger rod 6 Triangular raised protrusion

Claims (2)

[Claims] 1. An excavating blade of an appropriate shape is attached to the tip,
An elongated auger rod having a certain length is continuously provided on the upper part of an auger head formed by forming a conical surface on the upper part of the cutting blade and attaching a few disturbing blades on the conical surface,
Further, a ground improvement device characterized in that several triangular raised protrusions are formed on the shaft circumferential surface of the auger rod in a loose spiral shape over the entire length in the vertical direction of the shaft. 2. The ground improvement device according to claim 1, wherein the diameter A of the cutting edge of the cutting blade, the disturbing blade, or the like is approximately the same as the diameter B of the triangular raised protrusion attached to the auger rod. A ground improvement device characterized by being formed and provided.