JP2015140581A - Ground improvement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of easily constructing a pile in a rectangular shape, due to being unable to construct a rectangular foundation thereby, though a constructible concrete pile is all in a columnar shape in a conventional this system, since a method is used many for constituting a pile by soil and a cement by hardening together, by injecting cement milk into its agitated part, by deeply digging and advancing, while agitating by an agitation blade in a pile shape by a ground improvement method.SOLUTION: A ground improvement device is for constituting a foundation pile by mixing and hardening the cement milk by agitating the ground, and a nozzle for injecting the cement milk into a tip part, a tip excavation blade for excavating in the advance direction and a horizontal excavation blade having a rotary shaft at a right angle to a rotary shaft of the tip excavation blade, are provided by at least two by opposing by sandwiching the central axis on the root side from the tip excavation blade.

Description

  The present invention relates to a ground improvement device.

  When building a building, if the ground is below a certain strength, it must be improved. As ground improvement, there are surface layer and deep layer, but when a large building or ground is very weak, generally deep improvement is performed.

  Deep improvement is generally a method of hitting piles of concrete to the depth, but this is difficult, so the soil is agitated in a pile shape while stirring with a stirring blade, the soil is not taken out, it is stirred A method is often used in which cement milk is poured into parts and cured together to form soil and cement piles. For example, it is as described in Prior Art Document 1.

  In this method, it is not necessary to drive a long pile, and a pile close to concrete can be easily built in the ground.

JP-A-7-158052

  However, in this conventional method, the concrete piles that can be constructed are all cylindrical. Since this is a type in which the stirring blade (excavation blade) at the tip rotates, naturally the cross section becomes circular.

  When building a large and high-rise building or the like (of course, not only that), there is a case of building a rectangular base (a rectangular parallelepiped as a base). In such a case, even if the piles are constructed in contact with each other, there is a gap between the circles and they are not completely filled. In order to prevent this, it is necessary to excavate redundantly, and there is a problem in that the strength is different between the part where the cement milk is injected and the other part. In addition, useless cement is used to ensure strength.

  Therefore, in this industry, it has long been desired to dig into a rectangular shape with the same time and effort as before. Therefore, the present invention provides an apparatus that can easily construct a pile in a rectangular shape.

  In view of the above situation, the present inventors have completed the ground improvement device of the present invention, the feature of which is to stir the ground, mix and harden the cement milk to form the foundation pile A nozzle for injecting the cement milk to a tip, a tip excavating blade for excavating in a traveling direction, and a horizontal excavating blade having a rotation axis perpendicular to the rotation axis of the tip excavating blade; The point is that at least two of them are provided facing each other across the central axis from the wing to the base side (upper side).

  The ground improvement referred to in the present invention refers to the overall improvement of the strength of the soft ground, foundation construction, reinforcement further below the foundation, and other improvements to the ground, regardless of whether or not a building is constructed on it. .

  Here, the cement milk may be normal and need not be special. In short, what is necessary is just to mix with soil and to harden. Usually, it is liquid, but it can also be powdered in wet soil.

  In the present invention, the term excavation is used including the concept of simple stirring and intrusion in soft ground. A deep layer (a depth of 3 m or more) is suitable for the place of use, but it is not limited to this, and any depth may be used.

  It has a nozzle for injecting cement milk at the tip. Normally, liquid is ejected, but in the case of powder, powder is ejected. The tip portion here means a place where cement milk is sprayed and is effective, and does not mean only the most advanced portion. The more fundamental side (upper side) may be sufficient. However, there is a problem because the tip cannot be mixed at least above a certain level (about 1 m) above a horizontal excavation blade described later. Of course, the most advanced part is preferable.

  The tip excavation blade is provided at the tip portion that penetrates into the ground, and the rotation axis is parallel to the penetration direction. As the shape, a rotating plate-like body (a rod body or a twisted shape) may be provided with excavation claws (usually a plurality). The excavation claw not only stirs the soil, but also crushes the clot and crushes stones (it does not matter if it does not break depending on the ground). The number of plate-like bodies is preferably four, but basically two or more are possible. However, an even number is preferable from the balance of force. The excavation claw itself may be exchangeable, or the excavation claw may be provided with an exchangeable member at the tip of the excavation claw. The reason for exchanging is because the member is cut by excavation.

Since the plate-like body is fixed to the rotating shaft, a type in which the rotating shaft is fixed to the center of one long plate-like body may be used. In this case, the number is counted as two. The excavation claw and its tip replacement member are preferably an alloy having high hardness.
The number and shape of excavation claws, the fixing method, etc. are free.
Further, another excavating blade (agitating blade) which is a horizontal excavating blade having the same rotation axis as the tip excavating blade and a rotation axis perpendicular to the rotation direction of the tip excavating blade may be provided further upward. This is to make the mixing more effective.

The horizontal excavation blade has a rotation axis perpendicular to the tip excavation blade described above, and is provided on the root side from the tip excavation blade. Even on the root side, the vicinity of the tip excavating blade is preferable from the viewpoint of mixing. The vicinity here means that the rotating portion of the tip excavating blade and the rotating portion of the horizontal excavating blade are not in contact but are very close. For example, the lowermost part of the rotation circle of the horizontal excavation blade and the uppermost rotation part of the tip excavation blade are at a position separated by 0 to 40 cm, preferably about 5 to 20 cm.
In terms of shape, it consists of a plate-like body and excavation claws (the number and shape are free) and is the same as the tip excavation blade. The number of plate-like bodies is also 2 or more, and even numbers are preferable as in the case of the tip excavating blade. The excavation diameters of the horizontal excavation blade and the tip excavation blade are preferably the same. For example, even if there is a difference, it is within 10%.

  At least two horizontal excavation blades are provided facing each other. The direction of rotation is arbitrary, but reverse rotation is preferable. This is because it is not preferable to apply a force that moves in the lateral direction (horizontal direction).

  In order to increase the excavation (mixing) volume of the horizontal excavation blade, it is preferable that the excavation claw is fixed to the plate-like body at an angle. For example, if the same thin excavation claw is provided in the same direction as a drilling blade in a plate-like body parallel to the rotation direction, if the excavation blade does not move, the stirring volume is very small, and the plate-like body is Only its thin circle that rotates. On the contrary, if the excavation claw is fixed at an angle to the plate-like body and the excavation claw is lengthened, the stirring volume increases.

As one aspect of the present invention, it is preferable that the agitating area perpendicular to the rotation surfaces of the two horizontal excavation blades is 1/6 (as the total of the horizontal excavation blades) or more of the area excavated by the tip excavation blades. The “rotating surface of the horizontal excavation blade” is naturally in the vertical direction in normal use (forms a pile vertically). The stirring area is an area perpendicular to the rotating surface, that is, an area in the horizontal direction. In other words, this is the projected area when the stirring blade rotating in the vertical direction is viewed from above.
There are usually two horizontal stirring blades on the left and right, but they may be arranged so as to overlap more. In this case, all the total stirring areas should just be 1/6.
Further, apart from this horizontal stirring blade, a similar stirring blade may be provided on the more fundamental side.

The agitating area perpendicular to the rotating surface of the horizontal excavation blade is increased (1/6 or more) because the excavation is carried out in a circular shape by the tip excavation blade and then excavated into a rectangle from both sides, so that it is almost rectangular. This is to enable excavation in the shape. The reason why the horizontal excavation blade is possible not in all directions but in two directions is that the above-described horizontal area is large, so that the intermediate portion (the portion that is not stirred in a strict sense) is also broken by the nearby stirring. Of course, it is possible to provide not only two sides but also a little smaller one on the other side or two sides, and provide these horizontal excavation blades in a total of three or four directions.
The same type of drilling blade (excavation blade, stirring blade) may be provided further upward. This is to make the mixing more effective.

  In addition, the above-mentioned “the stirring area perpendicular to the rotating surface of the horizontal excavation blade is 1/6 or more (in total) of the excavation area of the tip excavation blade” is preferable because the excavation shape is more rectangular. It is to make it. Furthermore, 1/4 or more and 1/3 or more are more suitable. Above 1/3, it was very suitable for most soils.

  In order to obtain such an excavation shape, the mounting angle of the plate-like body and the excavation claw and the length of the excavation claw are problems. Further, in order to increase the horizontal excavation area, it is preferable to change the direction instead of tilting and fixing the excavation claws in the same direction. Further, the number of excavation claws may be increased, the excavation claws may be lengthened, or both may be performed to increase the excavation area. Of course, as described above, three or more horizontal excavation blades may be used.

  In the present invention, the point is to use the rotary shaft of the tip excavator blade and the excavator blade whose direction of the rotary shaft is perpendicular. Of course, the drive source is usually hydraulic, but it is only necessary to provide a gear for changing the rotation in the horizontal direction in the portion of the horizontal excavation blade. For example, a worm gear or a bevel gear.

  The cement milk of the device of the present invention is injected from the tip through a hydraulic oil and another pipe (either a double pipe or a parallel pipe). The operation of the present invention causes the apparatus of the present invention to penetrate into the ground normally vertically. Of course, it is not excavating rocks and the like, but only to improve soft ground and to build piles such as foundations, so mixing with soil is the main. Therefore, a mechanism for conveying the excavated soil upward is not necessary. That is, cement milk is jetted and mixed while excavating and stirring.

  When reaching the deepest part, the apparatus is generally pulled out from that point while rotating the excavating blade. This just waits for curing.

The excavator of the present invention has the following great effects.
(1) It can be excavated deeply into a substantially rectangular shape with only rotational movement.
(2) Since a concrete-like pile can be constructed in a rectangle, it is easy to construct a large rectangular pile. Moreover, it can be constructed without waste.
(3) Since it is a rectangular pile, it is easy to construct it in a connected manner.
(4) The device itself is simple and can be manufactured relatively inexpensively.

It is a front view of the ground improvement apparatus 1 which concerns on this invention. It is a bottom view of the example of FIG. It is a top view of the example of FIG. It is a right view of the example of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The following embodiments are merely examples of the present invention, and the present invention is not limited to these embodiments.

  FIG. 1 is a front view showing an example of a ground improvement device 1 according to the present invention. There is a gear box 2 in the center, and a gear for transmitting the rotation in the lateral direction is housed. On the upper side, a connecting portion 3 is provided for connection with a driving source of a driving device (such as a pile driver or a boring device). A cement milk pipe and the like are also connected together.

  A tip excavation blade 4 is provided below the gear box 2, and a cement milk injection nozzle 5 is provided at the tip. Two plate-like bodies 6 are fixed to the tip excavation blade 4, and excavation claws 7 are attached to the tip of the excavation claw 7 in a replaceable manner.

Horizontal excavation blades 8 are provided facing each other laterally from the gear box 2. The horizontal excavation blade 8 includes a horizontal plate-like body 9 and a horizontal excavation claw 10. There are four horizontal plate-like bodies 9, and three horizontal excavation claws 10 are fixed to each. The horizontal excavation claw 10 has a different mounting direction for each horizontal plate-like body 9 as seen at the right end of the front view. However. In this example, the fixed angle is substantially the same (about 15 degrees).

  Thus, the “horizontal excavation area” of the horizontal excavation blade is increased by changing the fixing method of the horizontal excavation claw 10 and providing it with an angle. As can be seen at the left end of the front view, the left horizontal excavation wing is the same, but the right and left horizontal excavation claws are opposite in length and breadth.

  FIG. 2 is a bottom view of the example of FIG. In this figure, it can be seen that there are two tip excavation blades 4 and three excavation claws 7 are fixed to one plate-like body 6. The fixing direction of the excavation claw 7 is opposite on the left and right, and the tip is directed in the rotational direction.

FIG. 3 is a plan view of the example of FIG. In this figure, it can be seen that the horizontal excavation claw 10 of the horizontal excavation blade 8 is fixed to the left and right oppositely. In addition, the plane excavation area of the horizontal excavation blade, which is a major point of the present invention, is indicated by a dashed-dotted line here. Since the excavation claw is provided in a different direction, the excavation is carried out almost entirely within the one-dot chain line by rotation. Here, the excavation lateral length L is preferably 1/8 (1/4 when the two are combined) or more, more preferably 1/6 (1/3 when the two are combined) or more.
The “horizontal excavation area” in FIG. 3 is what is compared with the area excavated by the tip excavating blade. In this example, the sum of the two is about 1/3. That this area is large means that the width in the left-right direction in this figure is large. As a result, the cross-sectional shape of the excavation, that is, the shape of the excavation (the plan view shape of the stirred ridge) becomes almost rectangular. This is a major feature of the present invention.

  FIG. 4 is a right side view of FIG. In this figure, the excavation claw 7 of the tip excavation blade 4 is different from the lateral excavation blade 8, and all are provided so as to be inclined toward the tip side. Further, the horizontal excavation claw 10 looks the same, but the one attached to the plate member in the horizontal direction is attached to the plate member in the vertical direction with its tip going deeper than the plate member. As for the thing, the tip has come to the near side rather than a plate-shaped object. This is the opposite on the left and right, but the same is true for the left side drilling wing.

DESCRIPTION OF SYMBOLS 1 Ground improvement device 2 Gearbox 3 Connection part 4 Tip excavation blade 5 Cement milk injection nozzle 6 Plate body 7 Excavation claw 8 Horizontal excavation blade 9 Horizontal plate shape body 10 Horizontal excavation claw

Claims (4)

A foundation pile is formed by stirring the ground and mixing and hardening cement milk to form a foundation pile, a nozzle for injecting the cement milk to the tip, a tip excavating blade for excavating in the traveling direction, and the tip excavation A ground improvement device, wherein at least two horizontal excavation blades having a rotation axis perpendicular to the rotation axis of the blades are provided facing each other across the central axis on the base side from the tip excavation blade. 2. The ground improvement device according to claim 1, wherein the horizontal excavation blade is provided on the root side of the tip excavation blade and in the vicinity of the tip excavation blade. The ground improvement device according to claim 1 or 2, wherein a stirring area perpendicular to the rotation surface of all the horizontal excavation blades is 1/6 or more of an area excavated by the tip excavation blade. The ground improvement device according to any one of claims 1 to 3, wherein the number of all lateral excavation blades is two.

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