JP2734291B2 - Ground excavation method using bucket type excavator - 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 excavating the ground with a bucket type excavator such as a Kelly excavator, and more particularly to a technique for preventing a decrease in excavation work efficiency due to excavated earth and sand adhering to a bucket. .

[0002]

2. Description of the Related Art When excavating highly viscous ground such as a Kanto loam using a Kelly excavator, excavated earth and sand tends to adhere to a bucket, which lowers work efficiency. Excavation work cannot be performed smoothly when a large amount of earth and sand adheres to the bucket. Therefore, the operation must be temporarily suspended and the earth and sand adhered to the bucket must be removed. Usually, the earth and sand attached to the bucket is manually scraped off using a scoop or the like. In order to prevent the earth and sand from sticking to the bucket, measures such as applying a release agent to the bucket surface and attaching a polyethylene sheet may be taken. However, such surface treatment for preventing adhesion of earth and sand does not last long. In other words, when excavating a boulder or a gravel layer, the release agent or sheet on the bucket surface is easily peeled off, and the effect of preventing sediment adhesion is immediately lost. Therefore, it is necessary to rely on the work of scraping off the attached earth and sand by human power.

[0003]

The task of manually scraping off the soil attached to the bucket using a scoop or the like is extremely labor intensive and inefficient. An object of the present invention is a construction method in which excavation is performed by a bucket type excavator in a state where muddy water is filled in an excavation hole to prevent collapse of a wall surface during excavation,
An object of the present invention is to make it possible to efficiently remove excavated earth and sand from a bucket by simple means as efficiently as possible without hindering repetitive operations of excavation and earth removal, so that excavation work can proceed smoothly.

[0004]

Therefore, according to the present invention, in a construction method in which excavation is carried out by a bucket type excavator in a state in which muddy water is filled in an excavation hole, a path near a path where a bucket moves up and down every time excavation and earth removal is repeated. In addition, an appropriate metal member is arranged in muddy water above the excavation hole, and at least when the bucket to which the excavated earth and sand passes passes near this metal member, the bucket is used as a negative electrode, and the metal member is used as a positive electrode. A DC voltage was applied while keeping both electrodes in a non-contact state, and hydrogen gas was generated from the surface of the bucket by electrolysis, thereby weakening the bond between the bucket and the attached sediment.

[0005]

[Function] When two electrodes are inserted in water and a DC voltage is applied, a current flows in the water and electrolysis occurs on the electrode surface.
Hydrogen gas is generated on the negative electrode side. The same phenomenon occurs between the bucket and the sediment in the muddy water of the excavation hole. That is, the metal bucket is a negative electrode, and the metal member is a positive electrode. A current by ion conduction flows in the muddy water, and hydrogen gas is generated from the bucket surface. Due to the gas expansion effect at the time of gas generation, the bonding force between the bucket surface and the attached sediment is greatly reduced, and the attached sediment is separated and falls off.

[0006] Such a step of removing the sediment attached to the bucket is incorporated in the step of moving the bucket up and down every time excavation and earth removal are repeated, so that the attached sediment can be removed almost without hindering the excavation operation.

[0007]

FIG. 1 shows a basic embodiment of the excavation method according to the present invention. In FIG. 1, reference numeral 1 denotes a kelly bar, 2 denotes a clamshell bucket attached to the lower end of the kelly bar 1, and 3 denotes a hole being drilled by the bucket 2 of the kelly excavator. In the method of the present invention, excavation is performed with the muddy water 4 filled in the hole in order to prevent collapse of the wall surface of the excavation hole 3. The bucket 2 has a hole 3 every time excavation and
Back and forth between the bottom of the car and the ground. That is, the bucket 2 is dropped with the blade of the bucket 2 open, the blade edge of the bucket 2 is cut into the bottom ground of the hole 3, and the bucket 2 is squeezed by the hydraulic jack to seize the earth and sand. Next, bucket 2
Is lifted to the ground, the sediment caught by the bucket 2 is lifted, transported to the earth discharging site on the ground, the bucket 2 is opened, and the sediment caught is dropped. And again bucket 2
Is moved to the bottom of the excavation hole 3 and the above operation is repeated.

A portion of the excavation hole 3 close to the ground is widely excavated (the portion is called a trench), and a metal member 5 such as an iron plate serving as a positive electrode is placed in the muddy water 4 in the trench. . As described above, when the bucket 2 reciprocates between the ground and the bottom of the hole 3 and passes through the trench, the bucket 2 is arranged to pass near the metal member 5 without contacting the metal member 5.

Further, a DC power source 6 comprising a rectifier or a battery is prepared, the metal member 5 is connected to the positive terminal of the DC power source 6 by a cord, and the metal bucket 2 is connected to the DC power source 6 by an appropriate connecting means. Connect to negative terminal. When a DC voltage is applied between the bucket 2 and the metal member 5 by the power supply 6 when passing through the metal member 5, a current flows by ion conduction into the muddy water 4, and the surface of the electrode (the bucket 2 and the metal member 5) , And hydrogen gas is generated from the surface of the bucket 2, which is a negative electrode. The lump of earth and sand adhering to the surface of the bucket 2 rises due to the expansion action of the gas. For this reason, even when excavating, it is possible to prevent the earth and sand from adhering to the bucket 2, and it is possible to reliably cause the adhered earth and sand to fall off from the bucket 2 when discharging the earth.

In a general situation, when a voltage of 2 to 25 V is applied between the bucket 2 and the metal member 5, 30 to 350V is applied.
A current of about mA flows. And, the larger the energizing current, the more gas is generated from the surface of the bucket 2 and the effect of removing the attached sediment is increased, so that the attached sediment can be removed in a shorter time.

According to the present invention, if electricity is supplied at least when the bucket 2 passes through the trench, the deposited earth and sand can be separated by the generation of gas. Of course, it is easy to peel off the earth and sand. Also, electricity may be supplied only when the bucket 2 passes through the trench.
Needless to say, it is better to continuously supply power during the excavation and earth removal work. Furthermore, when the excavation / discharge operation is completed, the bucket 2 can be stopped in the trench for an appropriate time and energized to remove the sediment attached to the bucket 2, and the subsequent new excavation operation can be performed effectively. Can be. In addition, the energization time (the time of the step of removing the attached soil) can be shortened as the energization current increases.

[0012]

As described above in detail, according to the present invention, the bucket excavator incorporates the earth and sand removing step in the reciprocating movement of the bucket with almost no hindrance to the excavation and earth removal work steps. Ground excavation work can be efficiently performed. In the soil removal process, gas is generated from the surface of the bucket by electrolysis using a very simple means that energizes between the bucket and appropriate metal members in the muddy water in the excavation hole and requires little maintenance. This weakens the connection between the bucket and the earth and sand, and the attached earth and sand can easily be dropped from the bucket. For this reason, the work is greatly reduced and more efficient than the work of scraping off the sediment attached to the bucket by a human force using a scoop or the like.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a basic embodiment of a ground excavation work according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Kelly bar 2 Bucket 3 Drilling hole 4 Muddy water 5 Metal member 6 DC power supply

Claims (1)

(57) [Claims] In a construction method in which excavation is performed by a bucket-type excavator in a state in which the excavation hole is filled with muddy water, the muddy water near the path where the bucket moves up and down and the upper part of the excavation hole each time excavation and earth removal are repeated. An appropriate metal member is arranged in advance, and at least when the bucket with the excavated earth and sand passes near this metal member, the bucket is used as a negative electrode, the metal member is used as a positive electrode, and both electrodes are in non-contact. A ground excavation method using a bucket-type excavator, wherein a DC voltage is applied while maintaining the state, and hydrogen gas is generated from the surface of the bucket by electrolysis, thereby weakening the bond between the bucket and the attached sediment.