JPH05209487A - Underground excavation method and casing tube - Google Patents

Abstract

PURPOSE:To smoothly excavate the ground by clearly removing soil in a casing tube as well as greatly reducing noise and vibration during the excavation of the underground. CONSTITUTION:While injecting a soil-gelling agent through a tube 18 passing from the upper end to the lower end in the longitudinal direction of a casing tube 10, the casing tube 10 is driven into the ground while being turned. Afterwards, air is sent into the tube 18 to push up soil in the casing tube 10 to the ground surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground excavation method and a method for excavating deep holes for pouring foundation concrete, holes for wells, etc., with less noise and vibration, and smoothly. It relates to a casing tube used.

[0002]

2. Description of the Related Art Conventionally, as a method for placing basic concrete, the Benot method, the reverse method, the continuous underground wall method and the like are known.

Of these, the Benoto method will be briefly described. First, a casing tube is built to dig a deep hole for placing concrete, and the inside of the casing tube is excavated by a hammer grab which is an excavator. If there is slime at the bottom of the hole, the slime is removed using a slime bucket, then the rebar cage is vertically installed in the hole, and the tremie pipe is further installed in the rebar basket. Then, concrete is poured into the hole from the upper end opening of the tremie pipe, passes through the gap in the reinforcing bar portion of the reinforcing bar basket, and is made to surround the outside of the reinforcing bar basket, and concrete is poured into the hole bottom. Then, while gradually pulling up the tremie pipe for pouring the concrete, if necessary, the tremie pipe on the upper end side is sequentially removed during work, and further concrete is poured continuously, and finally the hole mouth The concrete will be poured into and the pouring will be completed.

In other methods, the method of excavating a hole involves excavating the earth and sand in a casing tube using an excavator and scraping it to form a hole.

[0005]

Therefore, in the conventional excavation method, since a hammer grab or the like is used as an excavator, noise and vibration are terrible, and noise pollution for residents around the construction site. In particular, in addition to the problem that the construction in the middle of the night cannot be performed, there is a problem that the earth and sand in the casing tube cannot be completely removed.

The present invention has been made in view of the above-mentioned problems, and noise and vibration for excavation can be extremely reduced, and soil and the like in the casing tube can be removed cleanly, and An object of the present invention is to provide an underground excavation method and an excavation casing tube capable of smoothly excavating.

[0007]

In order to solve the above-mentioned problems, according to the present invention, after the casing tube is driven into the ground while pouring the sediment-gelling agent into the circulation means penetrating from the upper end to the lower end in the longitudinal direction of the casing tube. The underground excavation method is one in which air is sent from the upper end of the circulation means to push the earth and sand in the casing tube to the ground surface.

Further, the casing tube used in the above method has a structure in which at least one flow means for allowing the gelling agent and air to pass from the upper end to the lower end in the longitudinal direction is provided, and a plurality of cutting edges are provided at the lower end. ..

A pipe may be used as the circulating means, or a through hole may be formed in the casing tube itself. When using a pipe, the casing tube may have a double structure of an outer tube and an inner tube, and the pipe may be interposed therebetween.

[0010]

Operation: As shown in FIG. 5, the casing tube (10)
When the resin is driven into the ground (E) while rotating, the casing tube (10) is driven while the gelling agent is poured from the upper end of the flow means (18).

After the casing tube (10) has been driven to the final excavation position, next, the distribution means (18).
Air (A) is sent from the upper end of the compressor with a compressor. Then, at least the earth and sand (G) located in the vicinity of the inner wall surface of the casing tube (10) is gelled, and the earth and sand (G) is in a state of being easily moved. Therefore, as shown in FIG. When A) blows out from the lower end of the casing tube (10), the sand (G) in the casing tube (10) is discharged to the ground by the pressure of the air (A).

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the embodiments shown in the accompanying drawings. 1 and 2 are longitudinal sectional views and II- showing an embodiment of a casing tube (10) used for protecting a wall surface of a drill hole used in the method of the present invention.
It is a sectional view taken along line II.

The casing tube (10) has a length corresponding to the depth of the excavation hole, and in some cases, the length may reach 50 m. The casing tube (10) has a double structure of an outer tube (12) and an inner tube (14), and the outer tube (12)
In the gap (16) formed between the inner tube (14) and the inner tube (14), a circulation means (18) composed of a plurality of pipes is appropriately arranged in the longitudinal direction from the upper end to the lower end. In the illustrated example, the pipes (18) are shown to be arranged at equal intervals, but the present invention is not limited to this, and may be one pipe or more pipes. May be provided.

This casing tube (10) is shown in FIG.
The outer tube (12) and the inner tube (1
4) may be formed so as to eliminate the gap (16) between them, and a circulation means (18) formed of a through hole is formed in the longitudinal direction without forming a double structure as shown in FIG. You may do so. The point is that the casing tube (10) may be provided with a gelling agent for gelling earth and sand and a circulation means (18) through which air flows from the upper end to the lower end.

Examples of the gelling agent include muddy water containing bentonite as a main component, but the gelling agent is not limited to this, and any material may be used as long as it makes earth and sand into a gel. It may be.

A plurality of cutting edges (20) having high hardness are provided at the lower end of the casing tube (10). Therefore, when the casing tube (10) is driven into the ground while being driven, it can be driven smoothly.

The casing tube (10) used in the method of the present invention has the above-mentioned structure. Next, a method of excavating the casing tube (10) will be described with reference to FIGS.

First, as shown in FIG. 5, when driving the casing tube (10) into the ground (E) while rotating it,
The casing tube (10) is driven in while pouring the gelling agent from the upper end of the circulation means (18). Therefore, the gelling agent flows out from the lower end of the casing tube (10) through the flow means (18), and the earth and sand (G) inside the casing tube (10) is gelled. At this time, it is not necessary that all the earth and sand (G) in the casing tube (10) be gelled, and the earth and sand (G) located at least on the inner wall surface of the casing tube (10).
The object can be sufficiently achieved as long as it becomes a gel, that is, if the earth and sand (G) therein becomes easy to move with respect to the inner wall surface of the casing tube (10).

Then, the casing tube (10) is driven into the excavation position as shown in FIG. 6 while rotating the casing tube (10) as described above.

Casing tube (1
After driving 0), air (A) is then sent from the upper end of the circulation means (18) with a compressor or the like. Then, at least the earth and sand (G) located in the vicinity of the inner wall surface of the casing tube (10) is gelled, and the earth and sand (G) is in a state of being easily moved. Therefore, as shown in FIG. When A) blows off from the lower end of the casing tube (10), the pressure causes the earth and sand (G) in the casing tube (10) to be discharged to the ground. It is possible to easily excavate the ground by scraping this earth and sand (G).

Therefore, the conventional hammer grab is not required, and it becomes possible to excavate the ground with less noise and vibration.

If slime remains in the drill hole, the slime bucket can be used in the present invention to remove the slime.

[0023]

As described above, according to the present invention, a circulation means such as a pipe is provided in the longitudinal direction of the casing tube, and the casing tube is rotated and driven while pouring the sediment-gelling agent from the upper end of the circulation means. , Finally, by sending air by the circulation means, the earth and sand in the casing tube is pushed upward by the pressure of the air and flows out to the ground, so that an excavator such as a hammer grab for excavation is used. No need to use, noise and vibration are extremely reduced. In addition, it also has an advantage that the soil in the casing tube can be removed cleanly.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of a casing tube used in the method of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a cross-sectional view corresponding to FIG. 2 showing another embodiment of the casing tube.

FIG. 4 is a sectional view corresponding to FIG. 2 showing still another embodiment of the casing tube.

FIG. 5 is a schematic view showing an excavation step of the method of the present invention, showing the beginning of driving while rotating the casing tube into the ground.

FIG. 6 is a schematic view showing a state where the casing tube is driven to the end.

FIG. 7 is a schematic view showing a state in which the earth and sand in the casing tube are flowing to the ground by air feeding.

[Explanation of symbols]

 10 Casing Tube 12 Outer Tube 14 Inner Tube 18 Distribution Means 20 Blade Edge

Claims (5)

[Claims] 1. The casing tube is driven into the ground while pouring the earth and sand gelling agent into a circulation means penetrating from the upper end to the lower end in the longitudinal direction of the casing tube, and then air is fed from the upper end of the circulation means to the casing tube. The underground excavation method is characterized in that the sediment inside is pushed up to the ground surface. 2. The underground excavation method according to claim 1, wherein the sediment-gelling agent is mud containing bentonite as a main component. 3. A casing tube for excavation, comprising at least one flow means for allowing a gelling agent and air to pass from an upper end to a lower end in a longitudinal direction. 4. The casing tube for excavation according to claim 3, wherein a plurality of cutting edges are provided at a lower end portion of the casing tube. 5. The casing tube for excavation according to claim 3, wherein the flow means is composed of a plurality of pipes or through holes.