JP2645545B2 - Excavation press-fitting method and its equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavation press-fitting method used to press a pile into hard ground and an excavation press-fitting apparatus applied to the method.

[0002]

2. Description of the Related Art When a pile is pressed into a hard ground, an earth pressure during the press-fitting of the pile is reduced by excavating a portion near the press-fitting portion of the pile.

FIG. 7 shows a conventional excavator used for this excavation press-fitting, in which a spirally shaped auger 71 having a predetermined pitch is inserted into a casing 72. Auger 71
The auger shaft 73 is connected to a motor 75 via a reduction box 74, and the auger 7 is
1 rotates forward and backward. The upper part of the auger 71 is inserted into the casing 72 in the longitudinal direction with the lower part of the auger 71 pulled out. The casing 72 is formed in a cylindrical shape having a single diameter, and a discharge port 76 for discharging excavated soil raised by excavation of the auger 71 is formed on the upper side surface thereof in a communicating manner.

[0004] In this excavator, the auger 71 rotates forward near a press-fitting portion of a pile (not shown) to form a drilling hole near the press-fitting portion of the pile. The pile is pressed into the soil following the formation of the excavation hole, so that the pile can be easily pressed into the hard ground. In the forward rotation of the auger 71, the excavated soil is
Are lifted up between the blades and discharged sequentially from the discharge port 76. After the press-fitting of the pile, it is necessary to backfill the excavation hole excavated by the auger 71 to prevent loosening of the ground. This backfilling is performed by extracting the auger 71 from the excavation hole, returning the excavated soil to the excavation hole with a shovel or the like, and compacting the excavated soil.

[0005]

In the above-mentioned conventional press-fitting method, since backfilling of the excavation hole is performed manually after the auger is pulled out, it takes time and a great deal of labor is required. And In addition, backfilling to the original state is impossible, which causes a problem that the ground is loosened. Furthermore, at the time of excavation, in order to discharge excavated soil to the surroundings,
Surrounding pollution by excavated soil has also occurred.

The present invention has been made in view of such circumstances, and it is possible to refill an excavated hole in a short time, to save labor, to prevent the ground from loosening, and to contaminate the surroundings. It is an object of the present invention to provide an excavation press-fitting method that does not cause any problem. Another object of the present invention is to provide an excavation press-fitting device capable of suitably implementing this method.

[0007]

According to the excavation press-fitting method of the present invention, an auger is inserted into a casing formed into a shape whose diameter increases from a lower portion to an upper portion, and the auger is rotated in a forward direction into the soil. In addition to the propulsion, the excavated soil is stored in the casing by the forward rotation, and then the excavated soil is returned to the soil by reverse rotation while pulling out the auger.

[0008] The excavation press-fitting device of the present invention for implementing this method comprises an auger, a drive source for rotating the auger forward and reverse, and
A casing formed in a shape having a diameter increasing from a lower portion toward an upper portion.

[0009]

In the above construction, a digging hole is excavated by forward rotation of the auger. The excavated soil discharged by this excavation rises with the rotation of the auger, and the excavated soil is held between the blades at a high filling rate.

On the other hand, the upper part of the casing is swollen, and a large space is secured between the casing and the auger.
Therefore, the excavated soil that has risen due to the rotation of the auger is stored in the space above the casing, is not discharged outside, and does not pollute the surroundings.

Since the pile is pressed into the soil as the auger is propelled, the resistance at the time of press-fitting is small, and the pile can be easily driven even on hard ground. After placing the pile, the excavated soil stored in the casing is returned to the excavation hole by lifting the auger while rotating the auger in the reverse direction. As a result, the excavation hole is automatically backfilled, labor can be saved, and work can be performed in a short time.
In this backfilling, the pitch between the auger blades is small, and the excavated soil is held in a dense state between the blades, so that the soil with a high filling rate can be returned to the excavated hole while solidifying. Therefore, the ground state can be restored to the same state as before the excavation, and the ground does not loosen.

[0012]

1 shows an embodiment of a drilling press-fitting device 1 according to the present invention, and 2 denotes an auger. The auger 2 is formed by integrally forming a spiral blade 4 on an auger shaft 3. Reference numeral 5 denotes a gear box which houses a chuck for chucking the auger shaft 3 of the auger 2 and a reduction gear (both not shown) for transmitting a rotational force to the chuck. Is attached. The auger 2 rotates in the forward and reverse directions with the rotation of the hydraulic motor 6.

The auger 2 rotates forward and backward while inserted in the casing 7. The casing 7 has an upper part 7
It is formed in a shape in which the diameter of “a” is large and the diameter continuously decreases gradually toward the lower part 7b. As a result, the casing 7 has an upper portion 7a in an expanded state, and a large space 8 can be secured between the upper portion 7a and the auger 2, and excavated soil is stored in the space 8 as described later. . The lower portion of the auger 2 is extracted from the lower end of the casing 7, and the extracted portion excavates a digging hole. Reference numeral 9 denotes a hook disposed on the upper end surface of the casing 7, and a wire (not shown) from a crane or the like is hooked, whereby the entire apparatus 1 is suspended and excavation is performed.

FIGS. 2A and 2B show the structure of an auger, wherein FIG. 2A shows an auger 2 of this embodiment, and FIG. In the auger 2 of the present embodiment, the pitch P between the blades 4
1 is smaller than the pitch P2 of the blades 77 of the conventional auger 71. For example, while the pitch P2 of the conventional auger 71 is 260 mm, the pitch P1 of the auger 2 of the present embodiment is set to a half of 130 mm.
By thus reducing the pitch between the blades, the excavated soil 10 can be held at a high filling ratio between the blades. For example, when the diameter L of the auger blade is 260 mm, the filling rate of the excavated soil 10 is 0.5 in the conventional auger 71 having the pitch P2, but the filling rate is 1 in the pitch P1 of the present embodiment. be able to. Thus, the auger 2 of the present embodiment can raise or lower the excavated soil in a dense state, and can densely backfill the excavated hole as described later.

Next, using the device 1 as described above,
The method of press-fitting 0 will be described with reference to FIGS. FIG. 3 shows a state before the press-fitting of the pile 20, and the excavation press-fitting device 1 is arranged near the pile 20 to be driven. The excavation press-in device 1 is suspended by a wire 12 from a crane or the like, and excavates an excavation hole near the pile 20. In this case, the excavation press-fitting device 1 is appropriately stopped to prevent inadvertent rotation due to a reaction force during excavation. In the state of FIG. 3, the hydraulic motor 6 is driven to rotate the auger 2 in the positive direction indicated by the arrow, thereby causing the auger 2 to bite into the ground 21. Thereby, the auger 2 is propelled to the ground 21. At the same time, the bolt 20 is pressed into the ground 21 by a known pile press-in and pull-out machine (not shown). As this pile press-in and pull-out machine, for example, Japanese Patent Publication No. 2-2
No. 6016 can be used.

As the auger 2 is propelled, excavated soil is held between the blades 4 and rises in the casing 7. Since this excavated soil is stored in the space 8 between the upper part 7a of the expanded casing 7 and the auger 2 and is not discharged to the outside, the surrounding pollution can be prevented. In this case, a part of the excavated soil falls from the lower portion 7b of the casing 7, but the excavated soil falls into the excavation hole 23 and is captured by the auger 2 again. In the excavation by the auger 2, the pitch between the blades 4 of the auger 2 is small, and the soil on the ground 21 is held between the blades 4 at a high filling rate. That is, since the excavated soil is not exposed to the outside from the blade 4, the amount of excavated soil kneaded into the inner surface of the excavated hole 23 (see FIG. 4) is reduced, and the inner surface of the excavated hole 23 is not hardened. Thereby, the propulsion of the auger 2 can be performed smoothly.

FIGS. 4 and 5 show a state in which the excavation is completed, and an excavation hole 23 is formed in the ground 21 by the auger 2. On the other hand, the pile 20
Since it is press-fitted into the ground 21 in the vicinity thereof, the resistance at the time of press-fitting is small, and even if it is a hard ground, the press-fitting can be performed easily and reliably. In this excavation end state, excavated soil 10 is stored inside casing 7.

FIG. 6 shows the operation of pulling out the auger 2 after the pile 20 is press-fitted. The hydraulic motor 6 is driven in the direction opposite to that in FIG. 3, whereby the auger 2 is rotated in the direction indicated by the arrow. The auger 2 is pulled out from the excavation hole 23 by raising the entire apparatus 1 while continuing this rotation.
Since the auger 2 rotates in the reverse direction during this pulling out,
The excavated soil 10 stored in the casing 7 is held by the blade 4 of the auger 2 and returned to the excavation hole 23. in this case,
Since the pitch of the blades 4 of the auger 2 is small, they are held between the blades 4 at a high filling rate. As a result, the excavated soil 10 is returned to the excavation hole 23 while being hardened in a dense state,
The backfill of the excavation hole 23 is performed.

In the backfilling of the excavated hole 23, the excavated soil is filled in the excavated hole 23 in a dense state. For this reason, the ground state can be made the same as before the excavation, and the ground does not loosen. In addition, since the excavation hole 23 is backfilled at the same time as the auger 2 is withdrawn, not only can the backfill be performed in a short time, but also a worker for backfilling is not required, and labor can be saved.

The present invention is not limited to the above embodiment, but can be variously modified. For example, the excavation and press-fitting device 1 may be held by a known pile press-in and pull-out machine to perform excavation and backfilling. Also, it is not necessary to perform the press-fitting of the pile simultaneously with this excavation, and after forming the excavation hole by the above-mentioned operation,
It may be press-fitted in the vicinity of this excavation hole.

[0021]

As described above, according to the present invention, excavation is performed using an auger. However, since the excavated soil is stored in the casing, the surroundings are not polluted. In addition, since the backfill of the excavation hole is performed by pulling out the auger while rotating the auger in a reverse direction, the backfill can be performed quickly and with reduced labor. Since the excavated soil in the casing is backfilled while being solidified in a dense state with a high filling rate, the ground can be restored to the original state, and the ground does not loosen.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a drilling press-fitting device according to the present invention.

FIG. 2A is a front view of an auger of the present embodiment, and FIG. 2B is a front view of an auger of a conventional example.

FIG. 3 is a cross-sectional view of a first step of excavation press-fitting.

FIG. 4 is a sectional view of a second step of excavation press-fitting.

FIG. 5 is a plan view showing a pile press-fit state.

FIG. 6 is a cross-sectional view of an auger extraction process.

FIG. 7 is a sectional view of a conventional device.

[Explanation of symbols]

 2 Auger 4 Blade 6 Hydraulic motor 7 Casing P1, P2 Pitch

Claims (2)

(57) [Claims] 1. An auger is inserted into a casing formed in a shape having a diameter increasing from a lower portion toward an upper portion, and is propelled into the soil while rotating the auger in the forward direction. An excavation press-fitting method, wherein after excavated soil is stored, the excavated soil is returned to the ground by reverse rotation while pulling out the auger. 2. An excavation press-fitting device comprising: an auger; a drive source for rotating the auger forward and backward; and a casing formed to have a shape whose diameter increases from a lower portion to an upper portion.