JPH058288B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ground improvement method used in the civil engineering field and an apparatus used in the method.

[Conventional technology and its problems]

There are various devices and construction methods for creating sand drains underground for ground improvement. In some cases, the casing is filled with a ground improvement material such as sand, and when the casing is pulled out, the ground improvement material is discharged from the tip into the hole left behind to create a drain.

Such construction methods and equipment require measures to prevent the ground improvement material inside from rising up when the casing is pulled out. Conventionally, this method involves vibrating the casing itself or injecting air into the casing. ing.

However, in the conventional methods of applying vibration or injecting air, the equipment becomes large-scale, and when the casing is rotated and press-fitted, it becomes even more mechanically complicated.

The purpose of the present invention is to eliminate the disadvantages of the conventional example,
To provide a ground improvement method and device that can reliably prevent ground improvement materials from rising together in a casing by simply adding a simple member.

[Means for solving problems]

In order to achieve the above object, the present invention includes a rotary drive device that moves up and down along a leader, a casing whose upper end is connected to the rotary drive device and whose tip can be opened, and a length that is suspended from the upper end of the leader and inserted deeply from the upper end of the casing. When using a soil improvement device characterized by a long rod-like member and discharging the soil improvement material filled inside the casing from the tip when the casing is pulled out, the long rod-like member is inserted from the upper end of the casing and The gist of this is to extrude soil improvement materials.

[Effect]

According to the present invention, when the casing is pulled out, the ground improvement material inside the casing is pushed by the tip of the rod-like member, which remains as it is, and is sequentially discharged from the tip of the casing.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a side view showing one embodiment of the soil improvement device of the present invention, and Fig. 2 is a front view of the same. The leader mast, 3, indicates a cylinder for raising and lowering the leader mast.

This leader mast 2 has a motor 4 and a reducer 5.
A rotary drive device 6 is attached via a lift wire 7 so as to be able to rise and fall freely, and the upper end of the casing 8 is connected to this rotary drive device 6. 9 in the figure is a lifting motor for winding up and down the lifting wire 7.

In this way, the casing 8 is attached to the leader mast 2.
The casing 8 is suspended from a rotary drive device 6 along the upper end thereof, and has an opening for introducing soil improvement material at its upper end, and a bird's beak-shaped opening/closing lid 10 is provided at the tip so that the casing 8 can be opened.

On the other hand, a long rod-like member 11 is suspended from the upper end of the leader mast 2 by connecting its upper end with a pin, so that the long rod-like member 11 can be inserted into the casing 8 from the tip through the upper end opening. The long rod-shaped member 11 has a length that allows it to be inserted close to the tip of the casing 8, and
The thickness should be at least half the diameter of the

Next, to explain the construction method of the present invention, which is carried out using the above-mentioned equipment, Figs. 3 to 6 are longitudinal sectional side views showing each process. 6 is located above the leader mast 2, and the elongated rod-shaped member 11 is deeply inserted into the inside of the casing 8.

When the motor 4 is rotated in this manner, its torque is transmitted to the casing 8 via the reducer 5,
The casing 8 is pressed into the ground while rotating.

FIG. 4 shows a state in which the casing 8 has been inserted to a predetermined depth, and the rotary drive device 6 has also descended together with the casing 8 and is located below the leader mast 2.
The elongated rod-shaped member 11 has also come out of the casing 8.

Then, a ground improvement material 13 such as sand is charged and filled into the casing 8 through the upper end opening 12.

Next, the rotation drive device 6 is rotated by the power of the lifting motor 9.
Then, the casing 8 is pulled up, and at that time, the opening/closing lid 10 at the tip is opened and the ground improvement material 13 is poured out and remains in the hole. Further, as the casing 8 rises, the elongated rod-shaped member 11 moves up the casing 8 again.
Since the upper end of the soil improvement material 13 is pressed downward with its tip, the soil improvement material 13 is reliably pressed and does not twist together with the casing 8.

Then, the ground improvement material 13 that is sequentially discharged remains in the hole in the form of a column and forms a drain.

〔Effect of the invention〕

As described above, the ground improvement method and device of the present invention, when a casing with an openable tip is rotatably press-fitted into the ground and the ground improvement material filled inside the casing is discharged from the tip when the casing is pulled out, By simply adding a simple device without adding any means such as vibration or air, it is possible to mechanically and reliably prevent the ground improvement material from rising inside the casing.

[Brief explanation of the drawing]

Fig. 1 is a side view showing one embodiment of the soil improvement method and device of the present invention, Fig. 2 is a front view of the same, and Figs. 3 to 6 are longitudinal side views showing each step of the method of the present invention. . 1...Base machine, 2...Leader mast, 3
...Cylinder, 4...Motor, 5...Reducer,
6... Rotation drive device, 7... Lifting wire, 8...
... Casing, 9 ... Lifting motor, 10 ... Opening/closing lid, 11 ... Long rod-shaped member, 12 ... Upper end opening, 13 ... Ground improvement material.

Claims (1)

[Scope of Claims] 1. When a casing with an openable tip is rotatably press-fitted into the ground and the soil improvement material filled inside the casing is discharged from the tip when the casing is pulled out, a long rod-shaped member is inserted from the upper end of the casing. A soil improvement method characterized by inserting and extruding soil improvement materials. 2. A rotary drive device that moves up and down along the leader;
A ground improvement device comprising: a casing whose upper end is connected to the casing and whose tip can be opened; and a long rod-shaped member suspended from the upper end of a leader and deeply inserted from the upper end of the casing.