JPH02225797A - Soil improving method - Google Patents

Abstract

PURPOSE:To efficiently convey earth, and save an equipment cost and labor by interrupting the flow of the earth with a screw conveyor in a shield main- body temporarily, and by solidifying the earth with a mixing screw, to improve soil. CONSTITUTION:A soil removing screw 3 is composed of first and second conveying screws 31, 32 arranged linearly via a shutter 4, and a mixing screw 33 positioned above the shutter 4 and communicated with a space between the screws 31, 32. When the fluidity of plastic fluid-like earth conveyed by the screw 31 and mixed with ground improving agent cast from a soil improving agent casting device 7 is high, then a shutter plate 4a is moved upward, and the shutter 4 is closed, and earth is run into the screw 33. Besides, the rotation of the screws 31, 32, 33 is changed, or they are reversely rotated, and the earth is consolidated, and a plug zone is formed, and the solidification of the earth is promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a soil improvement method for improving soil quality excavated by a shield excavator so that it can be easily transported.

(Conventional technology) Conventional earth pressure balance type shield excavators inject wastewater into the face and the tip of the shield body to prevent water from spewing out while excavating. After taking in the soil, it is transported to the rear using a screw conveyor or other means of transporting the soil, but since the transported soil is turned into sludge, it is difficult to handle and transport, and it is also difficult to find a place to dispose of it. There were problems such as.

For this reason, conventionally, a sewage tank is installed on the ground near the one-shot shaft, and after the sewage is stored in the tank, a soil conditioner is added to solidify it, and the sewage is transported and disposed of.

However, the conventional method described above requires a place to install a sewage tank near the one-start shaft.

It is difficult to carry out construction if the space cannot be secured, and there are other problems, such as the need for special machinery and manpower to inject the soil conditioner, making it impossible to save on labor.

In addition, the excavated earth and sand that was carried out by the earth removal screw conveyor was piled up on a transport vehicle such as a trolley or a belt conveyor and could not be carried out, resulting in poor transportation efficiency and problems such as restrictions on the means of carrying out. .

This invention was made for the purpose of improving the above-mentioned problems, and aims to provide a method for improving soil quality in which the soil quality is improved while soil is being transported by a screw conveyor installed inside the shield body. It is.

(Means and operations for solving the problem) In order to achieve the above object, the present invention has been developed to remove sludge-like earth and sand excavated by the cutter head of an earth pressure balance type shield excavator and taken into the shield chamber. When the soil is transported out of the shield chamber by the first transport screw, a soil improver is introduced to solidify the sludge-like soil, and a shutter that can be opened and closed is installed between the first transport screw and the 2111 transport screw to mix the soil. If the fluidity of the sludge-like soil is high, the shutter is closed and the soil flows into the mixing screw, and the mixing screw further mixes the soil and soil conditioner while forming a plug zone. After promoting solidification, the solidified earth and sand is discharged from the second conveyance screw by being carried out through the second conveyance screw, and then transferred to a conveyance vehicle such as a trolley or a conveyance means such as a belt conveyor. This provides a soil improvement method that allows the shield to be carried out to the rear of the shield body.

(Embodiment) In Fig. 0, an embodiment of the present invention will be described in detail with reference to the drawings, l is a shield body of an earth pressure balance type shield excavator, and a front force lid head 2 is rotatably provided. The earth and sand excavated by the cutter head 2 is taken into a shield chamber Ib formed by dividing the front part of the shield body 1 by an airtight wall 1a.

Sewage mixed with bentonite, clay, etc., which has been pumped through a sludge pipe (not shown), is injected into the shield chamber Ib, which increases the earth pressure on the face side and the shield chamber Ib.
The pressure in the shield chamber Ib is balanced, and the earth and sand taken into the shield chamber Ib are taken into the shield body 1 from the shield chamber Ib by the soil removal screw conveyor 3. ing.

The earth removal screw conveyor 3 includes a first conveyance screw 31 arranged in a straight line with a shutter 4 interposed therebetween;
Located above the second w1 feeding screw 31 and the shutter 4, and the first and second feeding screws 31.3□
and a mixing screw 31 that communicates between the two.

The 1119th feeding screw 31 is housed in a cylindrical case 3a whose tip opens into the shield chamber Ib, and a drive motor 5 is provided in the middle of the case 3a.
It is designed to be rotated via a reducer 6 by
A soil improver feeding device 6 is installed at the upper part of the tip side of the case 3a to convey the sludge-like earth and sand in the shield chamber Ib to the vicinity of the shutter 4.

The soil conditioner feeding device 6 solidifies the sludge-like earth and sand, and the soil conditioner fed into the case 3a is
While the transporting screw 31 transports the sludge-like earth and sand, it is mixed with the earth and sand.

Further, the shutter 4 has a shutter plate 4a that is opened and closed in the vertical direction by opening/closing cylinders 4b provided on both sides, and by keeping this shutter plate 4a closed, the first
The earth and sand conveyed by the conveying screw 31 is blocked by the shatter plate 4a and flows into the mixing screw 3b from below.

The mixing screw 33 mixes the soil improver with the soil that has been excavated and turned into sludge because it has a high fluidity and could not be solidified sufficiently by the first conveying screw 32, thereby promoting solidification. , to form a plug zone by compacting earth and sand, and a mixing screw 31 is driven through a reduction gear 9 by a drive motor 8 provided at the rear end of the case 3b.
is rotated to form a plug zone within the case 3b by the action described later.

On the other hand, the soil that has been sufficiently mixed with the soil conditioner and solidified by the mixing screw 31 is transferred to the second conveying screw 3.
It is designed to be fed into the case 3C of the case 3C.

The 211th feeding screw 38 is rotated once by a drive motor IO provided at the rear end side of the case 3C via a speed reducer 11, and conveys the solidified earth and sand to the rear of the case 3C. In addition, a shutter 12 is provided at the rear end of the case 3C.

As shown in FIGS. 3 and 4, the shutter 12 includes a shutter plate 12a that is opened and closed in the vertical direction by opening/closing cylinders 12b provided on both sides.
2a is guided by a guide plate 12c to move up and down.

Further, a hopper 13 is provided protruding from the rear side of the shutter 12, and the earth and sand transported by the second transport screw 31 are collected when the shutter 12 is opened.

The material is dropped through the hopper 13 onto transport means such as a transport vehicle such as a Trofco or a belt conveyor for discharging soil, and is transported rearward by these transport means.

Next, a method for improving the soil quality of the earth and sand excavated by the shield excavator configured as described above will be explained. The earth and sand excavated by the cutter hood 2 as the shield main body 1 is propelled is taken into the shield chamber Ib, and the earth and sand are taken into the shield chamber Ib. It is mixed with the wastewater injected into 1b and turned into sludge.

After that, when the sludge-like soil is carried out from the shield chamber Ib by the first transport screw 31, the sludge-like soil is mixed with the soil conditioner input from the soil conditioner input device 6 and solidified, but the sludge-like soil flows. If the solidity is high, even if it reaches the shutter 4, it may not be sufficiently solidified and may be carried into the second Wi feed screw 31.

In such a case, the opening/closing cylinder 4b closes the shirt flap plate 4.
Move a upward to close the shutter 4. As a result, the earth and sand that has reached the shafter 4 is blocked by the shafter plate 4a and flows into the mixing screw 3°.
．． When the rotation of the second conveying screw 31.3 and the mixing screw 3 is changed or reversed, the mixing screw 1
The earth and sand are consolidated in the case 3b of the case 31 to form a plug zone.

Once the brag zone is formed, the soil and soil conditioner are rotated with the space between the inner wall of the case 3b and the screw filled with soil.

As a result, the soil and the soil conditioner are thoroughly mixed, the solidification of the soil is promoted, and a plug zone is continuously formed.

Another way to form the plug zone is as follows.

The shutter 4 is closed to forcibly stop the soil being transported by the first transporting screw 3, and in this state, the mixing screw 31 and the first transporting screw 31 are used to thoroughly mix the soil and soil conditioner. It can also be formed by mixing and solidifying.

On the other hand, the soil solidified by the mixing screw 31 flows into the second conveying screw 3o, and the second conveying screw 3! The earth and sand are transported to the rear by the shutter 12 which is opened, are dropped through the hopper 13 into the transport means, and are carried out to the rear by the transport means, but the soil has been sufficiently solidified by the mixing screw 3°. By increasing the rotational speed of the second conveyance screw 31, efficient conveyance can be achieved.

In the above embodiment, the mixing screw 31 is the first screw. Second
Although it is set above the conveyance screws 3+ and 3z, the same effect can be obtained from the sides and below.

Furthermore, the first. Second! l! If the feeding screw 31.3° is a screw with a shaft, it is also possible to co-manufacture the drive motor into one unit.

(Effects of the Invention) As detailed above, the present invention removes sludge-like earth and sand excavated by the cutter head of a shield excavator that excavates underground using the earth pressure balanced shield method and taken into the shield chamber. .

When the first transport screw is used to transport the soil from the inside of the shield chamber, a soil conditioner is added to improve the soil quality. A shutter and a mixing screw are provided between the feeding screws, and when the fluidity of the sludge-like earth and sand is high, the shutter is closed.

The soil containing the soil conditioner is supplied to the mixing screw, which forms a plug zone, and the plug zone further mixes the soil and soil conditioner to promote solidification. Therefore, the earth and sand discharged from the second conveyance screw becomes sufficiently solidified and easy to handle.

As a result, the earth and sand can be transported to the rear of the shield body using a transport vehicle such as a trolley or a transport means such as a belt conveyor, making it possible to transport the earth and sand more efficiently than in the case of conventional transport in the form of sludge. The inside of the tunnel can be kept clean because it is not contaminated by sludge.

Furthermore, by adopting this method, no special equipment or human labor is required for injecting the soil conditioner, so equipment costs can be saved and labor can be saved.

Furthermore, since there is no need to install a sewage treatment device such as a sewage tank near the starting shaft, it can be easily constructed even if the area near the starting shaft is narrow.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an embodiment of the shield excavator used in the soil improvement method of the present invention, Fig. 2 is an enlarged side view of the earth removal screw, Fig. 3 is an enlarged side view of the shafter, and Fig. 4 is an enlarged side view of the earth removal screw.
The figure is a front view of the same. 1... Shield body. 1b...Seal-Tochi Nakaba 2...Cutter head. 31...First conveyance screw 3,...Second conveyance screw. 33...Mixing screw. 4...Shafta. Patent Applicant: Komatsu Ltd. Patent Attorney: Osamu Matsuzawa Diagram 3 Procedure Amendment MaT 1999

Claims (1)

[Claims] The sludge-like soil excavated by the cutter head 2 of the shield excavator that excavates underground using the earth pressure balanced shield method and taken into the shield chamber 1b is carried out from the shield chamber 1b by the first conveying screw 3_1. When doing so, a soil conditioner is introduced to solidify the sludge-like earth and sand, and a shutter 4 and a mixing screw 3_3, which can be opened and closed, are provided between the first conveying screw 3_1 and the second conveying screw 3_2. If the fluidity of the sludge-like soil is high, the shutter 4 is closed to allow the soil to flow into the mixing screw 3_3, and while a plug zone is formed by the mixing screw 3_3, the soil and soil improver are further mixed and solidified. After promoting the conversion, the second conveying screw 3_
A soil improvement method characterized by carrying out the soil after passing through step 2.