JP2582724B2 - Drilling equipment for foundation ground - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a foundation ground for construction and the like, which excavates a solid hole wall while preventing collapse in the borehole and hardly discharges the ground. The present invention relates to a drilling device for a foundation ground whose main purpose is to easily and surely construct a deep portion of the foundation.

[0002]

2. Description of the Related Art Conventionally, among construction methods for constructing a foundation ground such as a building, a pile hole is excavated with a screw auger in the ground, and a foundation pile is excavated by placing an foundation pile in the pile hole. Various devices have been developed. However, since all of these drilling devices have been developed simply for excavating the ground, the pile support capacity after construction is extremely poor because the base of the ground is stirred unnecessarily during underground drilling. Not only does the pile hole often collapse after drilling, making work difficult afterwards, and at the same time as the above-mentioned excavation of the ground, a huge amount of excavated soil is accumulated on the ground and considerable expenditure and labor is required for the excavation process. It had disadvantages such as necessity.

[0003]

In order to solve such a drawback, several years ago, at the same time as the above-mentioned excavation of the pile hole, the excavation hole wall was more firmly pressed to prevent the collapse of the excavation hole wall and to prevent the excavation of the excavation hole wall. There has been a demand in the industry for an excavation device for the ground that minimizes the amount of earth removal. As a means for achieving the above object, the inventor first excavates the excavated soil simultaneously with the excavation in the ground using a conical screw auger that forms a consolidation surface of considerable pressure on the periphery of the screw blade piece. So-called no-discharge type earth excavation device that creates a solid hole wall by consolidating the hole peripheral wall more firmly by the correction action by the surface and the pressed soil surface and reduces the amount of earth lifted to the ground (Japanese Patent No. 113617)
No. 7) In addition, the peripheral surface of the auger rod is formed in a triangular or quadrangular surface, and the excavated soil is pressed against the peripheral portion of the excavation hole in the same manner as described above to form a strong hole wall without fear of collapse. (Patent No. 1308022), which has been effectively used in various places up to the present.
However, the drilling device developed above requires a considerable amount of rotational power because the following screw surface is completely in close contact with the wall surface of the hole that can be firmly pressed first, and it also generates in the hole. There is no air escape space, and this causes a sudden suction force to be generated in the hole when pulling out the rod, and it has been found that there is a risk that the hole wall that can firmly tighten the corner will collapse on the contrary due to the action of the suction force. . In view of the above problems, the inventor created an air escape site at the same time as an underground excavation hole, and prevented the generation of suction force in the hole by creating such an air escape site, and excavated a stronger pile hole. Further, as a feature of the present invention, not only a hard or soft ground layer can be adapted to the excavated geology, but also a few auger shaft connecting columns can easily and reliably excavate even a deep ground. It is an object of the present invention to provide a simple drilling device that enables the above.

[0004]

As a means for achieving the above-mentioned object, a drilling apparatus according to the present invention comprises, as shown in the drawing, an example in which a cutting edge 3 is provided at the lower end of an auger shaft 1.
And one or a plurality of vertically elongated screw blades 2 are radially twisted coaxially over the entire length of the auger shaft 1 and the largest diameter wide surface a of the screw blade 2 is provided. The notch portion 4 is formed in the largest-diameter wide surface piece b of the one screw blade 2 on the facing surface side. Further, in the present invention, an appropriately shaped tip blade 3 is provided at the tip, and several screw blades 2 are integrally provided at the upper portion, and the outer diameter c of the screw blade 2 is at least as described above. By forming the diameter of the excavation blade 3 to be substantially the same as the diameter α, it is possible to easily and reliably construct a beautiful pile hole having the same diameter in the upper and lower directions.

[0005]

In the following, a description will be given of an example of drilling of the foundation ground by this device. First, the entire device is set on a pile driving machine, fixed on a predetermined ground, and then the auger shaft 1 is driven and rotated to perform first excavation. The tip ground is disturbed by blade 3,
Simultaneously with the excavation, the excavated soil is excavated on the ground while cutting the hole periphery by the rotating action of the screw blade 2. However, the soil is intermittently beaten around the hole at the periphery of the screw blade 2 and the cutout portion 4. A hole wall which can be firmly tightened is formed while the screw blade 2 is provided with a notch 4 at the same time as the hole wall pressing as described above. A cavity is formed between the auger and the hole wall, and muddy soil, spring water, etc., as well as air congested in the hole in the cavity, that is, the space portion f, are naturally introduced, and the inside of the hole is muddy. The rotation load at the time is lubricated and also has the effect of reducing the suction force in the hole at the time of pulling out the rod, and the collapse of the hole wall can be completely prevented. Thus, a setting material d such as mortar is injected and filled from a mortar injection hole 6 opened at the tip of the excavating blade 3 into a pile hole e excavated on a predetermined ground to form a mortar column, and the mortar column is formed before setting of the mortar column. By driving the existing piles and H steel columns as core piles in the pillars, it is possible to easily and reliably obtain a strong foundation ground under the ground.

Further, the auger shaft 1 is connected and connected to a short and appropriate length at the site according to the depth of the excavated ground via the joint connecting portions 5 above and below the auger shaft 1 depending on the depth of the construction ground and the like. Therefore, it is possible to easily and surely and immediately excavate a pile hole having a length adapted to the above.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below. , A screw blade 2 having a constant diameter and a width c having a length b is formed so as to extend in a vertically elongated shape, and the maximum diameter wide surface piece a of the screw blade 2 is formed.
The notch portion 4 is formed by cutting a notch portion 4 on the widest surface piece b of the screw blade on the one surface on the facing surface side. The number of cutouts of the screw blades 2 is not limited to only the facing part depending on the hardness, resistance, etc. of the excavated ground.
It is also possible to provide several blade pieces I such as a number, for example, the smaller the number of blades, the greater the resistance at the time of excavation,
The greater the number of blades, the lower the resistance and the more it is possible to drill. Therefore, an appropriate number of cutouts 4 according to the geology of the construction target ground, etc.
A blade piece having the following is provided. As an example, the one shown in the illustration is a commonly used one, which is symmetrical about the auger shaft 1 and formed by twisting and extending the largest-diameter wide pieces a and b integrally on both sides. The notch portion 4 is notched in the one-side largest-diameter wide surface piece b. Reference numeral 3 denotes an appropriately shaped tip blade attached to the lower end of the auger shaft 1 and having a diameter c substantially equal to the diameter c of the screw blade 2. A mortar injection hole 6 is formed in the center of the cutting edge 3 and is connected to a mortar infusion pipe 7 formed longitudinally in the axis of the auger shaft 1.

Further, in the present invention, joint connecting portions 5 are provided above and below the auger shaft 1, and several auger shafts 1 are integrated in a long and short manner via the joint connecting portions 5 according to the depth of the construction ground. In this case, it is possible to easily excavate a pile hole having a length adapted to the ground depth at the site.

[0009]

According to the present invention, as described above, a vertically elongated screw blade 2 is formed by twisting left and right around the shaft periphery of the auger shaft 1. Since the cutout portion 4 is provided in one of the blade pieces of the wide-diameter surface pieces a and b, a notch portion 4 is provided in the recessed portion at the outer peripheral edge of the screw blade 2 simultaneously with the rotation of the screw blade 2. Strong hole wall e by intermittently hitting excavated soil
This has the effect of excavating into the ground to a predetermined depth while forming the ground, and also significantly reducing the amount of unloading to the ground to be excavated. That is, since the present invention has a shape in which the vertically elongated screw blades 2 are twisted over the entire length of the auger shaft 1, the frictional resistance at the time of excavation is very small, and a smooth excavation work can be obtained. Feather 2
The notch portion 4 is formed in the large-diameter wide surface piece b to form an acute angle edge of the notch portion 4 during the underground excavation, so that the underground excavation can be easily cut and the underground excavation can be easily cut. At the same time, it is formed in several places in the hole while excavating the space part f as an escape space for air, and by creating such a space part f, the suction force in the hole generated when the conventional auger is pulled out is suppressed. It also has the effect of preventing collapse of the pore wall caused by the suction force. In addition, unlike the ordinary screw blade rotation, the mortar coagulant to be injected into the hole is more easily and easily agitated by the rotating action of the screw blade 2 having the partially notched portion 4, and the mortar is sent deep into the hole. It also has the effect of pouring.

Further, as described in claim 2, the diameter c of the upper and lower screw blades 2 is formed to be approximately the same diameter as the diameter α of the excavating blade 3 so as to extend deep into the ground. It is possible to easily and surely construct a pile hole having a hole wall having substantially the same diameter.

According to a third aspect of the present invention, an auger shaft 1 is provided.
Joints 5 are attached to the upper and lower sides, and the auger shaft 1 having the shaft length according to the construction depth can be easily formed on the site through the joints 5 so that the length of the auger shaft 1 can be easily adjusted at the site. Can be easily excavated, and there is an effect that work such as transportation and storage is convenient.

[Brief description of the drawings]

FIG. 1 is an overall front view of a ground excavation apparatus according to the present invention.

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

FIG. 3 is a front view of the same according to another embodiment;

FIG. 4 is a ground excavation figure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Auger shaft 2 Screw blade 3 Cutting edge 4 Notch part 5 Joint connection part 6 Mortar injection hole 7 Mortar infusion tube a, b Large diameter wide surface piece

Claims (3)

(57) [Claims] 1. An auger shaft 1 having a cutting edge 3 at a lower end thereof, and a plurality of vertically elongated screw blades 2 radially twisted coaxially over the entire length of the auger shaft 1 in the vertical direction. A drilling device for foundation ground, wherein a cutout portion 4 is formed in the largest-diameter wide surface piece b of one screw blade 2 on the opposite side of the largest-diameter wide surface piece a of the screw blade 2. 2. A cutting blade 3 having an appropriately shaped tip at a tip portion, and several screw blades 2 are integrally provided on the upper portion thereof. 2. A digging apparatus for foundation ground according to claim 1, wherein an outer diameter width c is formed to be at least substantially the same diameter width as the diameter width α of the cutting edge 3. 3. Joint joints 5 are provided above and below an auger shaft 1 in which the screw blades 2 are integrally formed on the entire upper and lower portions of the shaft as described above. 2. The excavation device for foundation ground according to claim 1, wherein a plurality of auger shafts 1 are formed so as to be freely connected to each other in a short length according to the distance.