JPH0826746B2 - Shield excavator and soil improvement method for shield construction method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a soil improvement method for improving the soil excavated by a shield machine so as to be easily transported.

(Prior Art) In a conventional earth pressure balance type shield excavator that advances mud while injecting mud into the face of the face and the shield body to prevent water spouting, the excavated earth and sand enter the shield body together with the mud. After being taken in, it is carried out to the rear by means of earth and sand, such as a screw conveyor, but because the earth and sand that has been carried out is plasticized, it is difficult to handle and to transport, and it is also difficult to obtain a place to discard it. There was a problem.

For this reason, in the past, a muddy water tank was installed on the ground near the starting shaft, and once stored in this muddy water tank, a soil conditioner was added to solidify it, and it was transported and discarded.

However, the above-mentioned conventional method requires a place for installing a mud tank near the starting shaft, so that it is difficult to construct if a place cannot be secured, and it requires a machine and manpower to inject the soil improvement agent. There were problems such as labor saving.

In addition, since the earth and sand excavated and discharged by the soil discharge screw conveyor cannot be carried out by piled up on a transport vehicle such as a truck or a belt conveyor, the transport efficiency is poor, and there is also a problem that the transport means is limited. .

The present invention has been made for the purpose of improving the above problems, and an object of the present invention is to provide a soil improvement method for improving the soil quality while the soil is being conveyed by the screw conveyor installed in the shield body. Is.

(Means and Actions for Solving Problems) (1) A shield excavator for excavating the ground by a soil pressure balance type shield construction method, which has a earth and sand intake port above a screw conveyor for earth discharge. A shield machine having a screw conveyor for mixing, and a soil-improving agent input port provided on the screw conveyor for mixing chemicals.

(2) In the earth pressure balance type shield construction method of excavating the ground by a shield excavator, the plastic fluidized earth and sand that is excavated by the cutter head and taken into the shield chamber is taken into the drug mixing screw conveyor. , The soil improvement agent is input from the soil improvement agent input port provided on the chemical mixing screw conveyor, and the plastic fluidized sand and the soil improvement agent are mixed by the chemical mixing screw conveyor, and then the soil mixing screw conveyor is discharged. This is a soil improvement method of the shield method that takes in and removes soil.

Therefore, inject the sediment improver into the first-stage chemical mixing screw conveyor,
The flow is confused when the earth and sand is conveyed to the second-stage discharge screw conveyor, which causes the plastic fluidized sand and the earth and sand modifier to mix, and the soil modifier reacts during the conveyance of the two-stage screw conveyor. However, the improved earth and sand is discharged from the soil discharge port.

Embodiment An embodiment of the present invention will be described in detail with reference to the drawings. In the figure, 1 is a shield body of a soil pressure balance type shield excavator, in which a cutter head 2 is rotatably provided in the front part, and the plastic fluidized earth and sand excavated by the cutter head 2 is in the front part of the shield body 1. Is enclosed by the airtight wall 1a and is taken into the shield chamber 1b formed.

Into the shield chamber 1b, mud water mixed with bentonite, clay, etc., which has been pressure-fed through a mud pipe (not shown), is injected, and the earth pressure on the face side and the shield chamber 1b.
The pressure inside is balanced.

And the plastic fluidized earth and sand is discharged by the screw conveyor 3
Thus, it is taken into the shield body 1 from inside the shield chamber 1b.

The soil discharging screw conveyor 3 is a cylindrical case 3a.
With the structure in which the screw shaft 3b is provided, the front end of the case 3a is connected to the case 4a of the drug mixing screw conveyor 4 provided in the shield chamber 1b.

As shown in FIG. 3, the case 4a is formed in an almost inverted triangle, and the screw conveyor 3 for earth removal is provided at the bottom.
The tip end of the screw shaft 3b is protruded, and two screw shafts 4b and 4c of the drug mixing screw conveyor 4 are provided above the screw shaft 3b so as to be parallel to the screw shaft 3b and are horizontally separated from each other. Has been.

The screw shafts 4b, 4c are adapted to be rotated in opposite directions by a drive motor 5 provided on the base end side, and the tip ends of the screw shafts 4b, 4c are mounted on the case 4
The plastic fluidized earth and sand in the shield chamber 1b is projected to the side of the opening 4d that is open to the upper front side of the case 4a.
It is designed to be taken in.

On the other hand, on the upper side of the case 4a, a drug injection port 6 for injecting a drug to the tip side of each screw shaft 4b, 4c is provided.

These drug injection ports 6 are connected to a drug injection device 7 provided in the shield body 1 through a pipe line 8, and the soil conditioner injected from the drug injection device 7 is discharged from the drug injection port 6 by It is designed to be injected into the fluidized earth and sand taken up by the screw shafts 4b, 4c.

Next, the soil improvement method using the shield machine configured as described above will be explained. The earth and sand excavated by the cutter head 2 along with the propulsion of the shield body 1 is mixed with the muddy water injected into the shield chamber 1b to be plasticized. To be done.

After that, the screw shafts 4b, 4c of the screw conveyor 4 for mixing the medicine are taken into the case 4a, and the screws 4b, 4c are rotated in opposite directions by the drive motor 5, so that the plasticity taken in is increased. While stirring the fluidized earth and sand, send it into the interior of the case 4a.

Then, at this time, the soil conditioner injected from the chemical injection port 6 and the plastic fluidized sand are efficiently mixed.

The soil conditioner solidifies the plastic fluidized sand and sand. The mixing operation allows the plastic fluidized sand and sand to be solidified effectively, that is, the soil quality can be efficiently improved, and the soil whose soil quality has been sufficiently improved is discharged. It is taken into the case 3a in the shield body 1 by the screw shaft 3b of the earth screw conveyor 3 and further stirred and mixed while being conveyed in the case 3a to promote solidification, and to the rear end of the case 3a. Reach Then, after being discharged into the shield body 1 from a soil discharge port 3c provided at the lower part of the rear end side of the case 3a, it is loaded on a transportation vehicle 10 such as a dolly or a conveyor means such as a belt conveyor, and behind the shield body 1. Be transported to.

In the above-mentioned embodiment, the soil improving agent is injected into the earth and sand taken into the soil discharging screw conveyor 3 from the shield chamber 1b. However, the soil improving agent is injected into the earth and sand during transportation by the earth discharging screw conveyor 3. Then, the soil quality may be improved during the transportation of the sediment, that is, the plastic fluidized sediment may be solidified.

In addition, the screw 4 for mixing medicines is a shield chamber 1b.
A screw with a shaft may be used to take in the sand and sand, and a pad type screw may be used during transportation, and the positions of the screw shafts 4b and 4c may be set below or to the left and right of the screw 3 for discharging soil. Of course, it may be the direction.

(Effects of the Invention) As described in detail above, the present invention is one in which a soil conditioner is injected into a plastic fluidized soil from a drug mixing screw conveyor and then taken into an earth discharging screw conveyor. When the sediment improver is injected into the chemical mixing screw conveyor of the second stage and the sediment is conveyed from the chemical mixing screw conveyor to the second discharging screw conveyor, the flow is confused. The sediment improver is mixed, the soil improver reacts during the transportation of the second-stage transfer screw conveyor, and the improved sediment is discharged from the discharge port.

Then, the earth and sand discharged from the earth discharging conveyor into the shield body is solidified and becomes easy to handle.

As a result, since it can be carried out to the rear of the shield body by a transportation vehicle such as a truck or a conveyor such as a belt conveyor, the sediment can be carried out more efficiently and the inside of the excavated tunnel is The inside of the tunnel can be kept clean because it is not polluted by the fluidized soil.

In addition, by adopting this method, the soil improvement effect will be enhanced, and since no special equipment or manpower is required for introducing the soil improvement agent, it will be possible to reduce equipment costs and labor.

Furthermore, since it is not necessary to install a muddy water treatment device such as a tank near the starting shaft, it will be possible to easily perform construction even if the area around the starting shaft is small.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a shield machine used in the soil improvement method of the present invention, FIG. 2 is an enlarged sectional view in the vicinity of a chemical feeding device, and FIG. FIG. 1 ... Shield main body, 1b ... Shield chamber, 2 ... Cutter head, 3 ... Soil discharging screw conveyor, 4 ... Medicine mixing screw conveyor.

Claims (2)

[Claims] 1. In a shield machine for excavating the ground by the earth pressure balance type shield method, a screw conveyor for mixing chemicals having a sediment intake port is provided above the screw conveyor for discharging soil, and the screw for mixing chemicals is provided. A shield machine with a soil improvement agent inlet on the conveyor. 2. The plastic fluidized earth and sand excavated by the cutter head in the earth pressure balance type shield construction method of excavating the ground by the shield excavator and taken into the shield chamber is taken into the screw conveyor for mixing the chemicals. The soil conditioner is introduced from the soil conditioner input port provided on the mixing screw conveyor, and the plastic fluidized sand and soil and the soil conditioner are mixed by the drug mixing screw conveyor, and then taken into the soil discharging screw conveyor. Soil improvement method of soil shield method.