JPH0790844A - Pile formation construction method and device - Google Patents

Abstract

PURPOSE:To improve reliability by constructing the support force increasing parts reliably by forming these parts in an efficient shape according to a ground condition when the support force increasing parts are arranged, also obtaining plural support force increasing parts, and extending an excavating edge reliably. CONSTITUTION:An excavating extensible edge 6 to advance and retreat in the direction perpendicular to the axial direction of an excavating rod 1, is arranged on an excavating head 2 to be installed on the tip of the excavating rod 1 rotated by an optional rotary driving means. When excavation is carried out by rotating this excavating head 2, the excavating extensible edge 6 is advanced, and a diametrically expansive support part expanding in a flange shape is formed in an intermediate part of a pile.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pile construction method and apparatus.

[0002]

2. Description of the Related Art Generally, it is required that a pile of a house foundation is constructed with a length until the tip of the pile reaches hard soil called a support layer.

On the other hand, when the support layer is deep,
In order to avoid the need for constructing long piles, it is possible to increase the bearing capacity by making the tip of the pile a bulb-shaped expanded bottom pile.

Further, as an excavator for constructing the expanded bottom pile, after excavating to a predetermined depth, the excavating blade is enlarged to be excavable by reverse rotation.

[0005]

As described above, in the case of piles having the same diameter, the length of the support ground becomes long and the cost becomes high. In terms of construction, the machine becomes large-scale and pollution such as noise and vibration occurs.

On the other hand, the construction of expanded bottom piles does not require the length to the support ground, but the part where the support force is increased is limited to one point, the tip of the pile, so that the condition of the ground that is hard and soft multi-layered can be used effectively. You can't do it, and the efficiency of increasing the support capacity is also poor.

Further, the excavator for constructing the bottomed pile is constructed such that the excavating blade is rotated in the reverse direction to enlarge the excavating blade and then the excavating blade is enlarged, and it is impossible to judge whether or not the excavating blade is surely enlarged. Unable to build a reliable pile.

The object of the present invention is to eliminate the disadvantages of the conventional example and to provide a supporting force increasing portion, which can have an efficient shape according to the state of the ground, and moreover, a plurality of supporting force increasing portions. And to provide a highly reliable pile construction method and device capable of reliably constructing this supporting force increasing portion by reliably enlarging the excavating blade.

[0009]

In order to achieve the above-mentioned object, the present invention has a construction method in which an excavating head mounted on the tip of an excavating rod which is rotated by an arbitrary rotary driving means is attached to the excavating rod in the axial direction. An excavation expansion blade that advances and retreats in a right angle direction is provided, and when excavating by rotating this excavation head,
By advancing the excavation expansion blade, a diameter-expanding support portion that projects like a flange is formed in the middle portion of the pile. As an apparatus, the excavation head is attached to the tip of the excavation rod that is rotated by an arbitrary rotation drive means. In the pile forming device,
This drilling head is provided with a plurality of drilling expansion blades that advance and retreat in a direction perpendicular to the axial direction of the drilling rod with a hydraulic cylinder, and the drilling rod is a liquid injection pipe for cement milk and the oil supply to the hydraulic cylinder. It is a multi-rod with a built-in tube, and the gist is to provide a swivel for liquid or oil on the top.

[0010]

According to the present invention as set forth in claim 1, by forming a diameter-expansion support portion projecting like a flange at the middle portion of the pile, not at the tip end portion, the diameter-expansion support portion is formed in the upper layer of soft ground. The supporting force can be increased by engaging with the hard soil. Further, the expanded diameter support portion may be formed with a plurality of intervals.

According to the second aspect of the present invention, since the excavation enlarging blade is advanced and retracted by the hydraulic cylinder or the like, the enlarging excavation of a desired size for forming the diameter enlarging support portion is performed at an arbitrary depth position. Can be done reliably and reliably.

According to the third aspect of the present invention, in addition to the above action, the structure of the multiple rod can be simplified.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a partially cutaway front view showing an embodiment of the pile forming apparatus of the present invention, FIG. 2 is a cross-sectional plan view of a main portion, and FIG.
[Fig. 3] is a side view of a drilling head.

The apparatus of the present invention will be described first. As a so-called auger type excavator, an excavating head 2 is provided at the tip of an excavating rod 1 which is rotated by an arbitrary rotary drive means such as a hydraulic drive motor 3. In the figure, reference numeral 8 is a leader for vertically moving such a device, which is provided on a leader mast of a heavy machine such as a crawler as is well known.

The excavation rod 1 includes an outer pipe 1a, a middle pipe 1b,
It is a multiple rod composed of a triple pipe of the inner pipe 1c, and a swivel 4a for liquid and a swivel 4b for oil are provided on the upper part of the drill rod 1.
Is provided, and the inner pipe 1c is a liquid injection pipe capable of injecting cement milk or the like via the liquid swivel 4a, and the middle pipe 1b can be oiled to a hydraulic cylinder 5 described later via the oil swivel 4b. An oil injection pipe was used.

The excavating head 2 mounted on the tip of the excavating rod 1 has the excavating bit 2a which is planted downwardly like the ordinary excavating head.
Then, the excavation expansion blade 6 which moves forward and backward in the direction perpendicular to the axial direction of the excavation rod 1 is provided.

In the illustrated example, two digging and expanding blades 6 are provided in the upper and lower stages in alternate directions, but the number may be one or three or more. Further, the oil supply (drainage) to the hydraulic cylinder 5 for advancing and retracting the digging expansion blade 6 is performed by the middle pipe 1
b is connected.

The tip of the liquid injection pipe formed by the middle pipe 1b is
In this embodiment, the discharge pipe 7 is branched at the portion of the excavation head 2.

Next, a method of constructing a pile using the apparatus of the present invention will be described. When the excavating rod 1 and the excavating head 2 are rotated by the drive motor 3 and they are lowered along the leader 8, the excavating head 2 excavates,
At that time, if cement milk is poured out through the liquid injection pipe by the middle pipe 1b and the discharge pipe 7, this is mixed with the excavated earth and sand to form a soil senmet pile.

In this case, if the excavation enlargement blade 6 is advanced by the hydraulic cylinder 5 as necessary, the excavation enlargement blade 6 expands in a flange shape at the intermediate portion of the pile 9 as shown in FIG. The part 9a can be formed.

The expanded support portion 9a is formed not in the tip portion of the pile 9 but in an intermediate portion thereof with an arbitrary length, so that the support portion can be retained on the hard soil above the soft soil. Can be increased. Further, a plurality of the expanded diameter support portions 9a can be formed at intervals so that a necessary supporting force can be obtained even in the case of only soft ground without hard soil.

In addition to the expanded diameter support portion 9a, the pile 9
The fixing portion 9b may be formed at the tip of the.

[0023]

As described above, in the pile construction method and device of the present invention, the supporting force increasing portion can be provided with an efficient shape according to the state of the ground, and a plurality of The supporting force increasing portion is obtained, and the excavating blade is surely expanded, so that the supporting force increasing portion can be surely constructed, which is highly reliable.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of a pile forming device of the present invention.

FIG. 2 is a cross-sectional plan view of essential parts showing one embodiment of the pile forming device according to the present invention.

FIG. 3 is a side view of an excavating head showing an embodiment of the pile forming apparatus according to the present invention.

FIG. 4 is an explanatory view showing the shape of the pile in the pile construction method of the present invention.

[Explanation of symbols]

1 ... Drilling rod 1a ... Outer tube 1b ... Middle tube 1c ... Inner tube 2 ... Drilling head 2a ... Drilling bit 3 ... Drive motor 4a ... Liquid swivel 4b ... Oil swivel 5 ... Hydraulic cylinder 6 ... Drilling expansion blade 7 ... Discharge Pipe 8 ... Cylinder 9 ... Pile 9a ... Expanding diameter support 9b ... Fixing part

Claims (3)

[Claims] 1. An excavation head attached to the tip of an excavation rod that is rotated by an arbitrary rotation driving means is provided with an excavation expansion blade that advances and retracts in a direction perpendicular to the axial direction of the excavation rod.
A method for constructing a pile, characterized in that, when the excavation head is rotated to perform excavation, the enlarged expansion blade is advanced to form a diameter-expansion support portion projecting in a flange shape in an intermediate portion of the pile. 2. An apparatus for constructing a pile in which an excavation head is mounted on the tip of an excavation rod which is rotated by an arbitrary rotary drive means, wherein the excavation head is advanced by a hydraulic cylinder or the like in a direction perpendicular to the axial direction of the excavation rod. An apparatus for constructing a pile, which is provided with a digging expansion blade that exits. 3. The pile construction according to claim 2, wherein the excavating rod is a multiple rod containing a liquid injection pipe for cement milk or the like and an oil supply pipe for a hydraulic cylinder, and a liquid swivel or an oil swivel is provided on the upper part thereof. apparatus.