JPS5836716B2 - shield tunneling machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shield excavator that can use a portion of excavated earth and sand as a backfilling material for segments sequentially arranged behind the shield excavator main body.

A shield excavator used for excavating soft ground with a high moisture content is of the so-called earth pressure type, and has a pressure chamber filled with excavated earth and sand and whose face is held by the earth pressure of the earth and sand.

The pressure in the pressure chamber must always be maintained at a pressure commensurate with the groundwater level even during excavation to prevent the face from collapsing.

For this reason, a volumetric pump or the like that meets the above purpose is used as an earth removal device for discharging the excavated soil taken into the pressure chamber to the atmospheric pressure chamber side.

On the other hand, a backfilling material is filled (backfilling) between the segments sequentially arranged behind the shield tunneling machine main body and the ground around the segments.

Conventionally, backfilling material was prepared separately outside the machine.

The present invention was made by focusing on the fact that the discharged earth and sand from an earth pressure type shield excavator has a high moisture content and that a positive displacement pump is used as an earth removal device. This paper proposes a shield excavator that can be used as a backfilling material, and examples thereof will be described below based on the drawings.

Reference numeral 1 denotes a shield tunneling machine main body, and the main body 1 is divided by a partition wall 2 into a pressure chamber 3 and an atmospheric pressure chamber 4.

At the front of the pressure chamber 3, there is a cutter head 6 facing the face 5.
is provided, and a large number of rotating packets 7 that are continuous in the circumferential direction are fixed to the outer peripheral surface of the back of the cutter head 6.

A driven gear 10 that meshes with an output gear 9 of a drive motor 8 fixed to the shield excavator main body 1 side is attached to the rear of the rotating packet T.

A screw conveyor 11 extending between the pressure chamber 3 side and the atmospheric pressure chamber 4 side is disposed in the partition wall 2, and the casing 12 that covers the screw conveyor 11 has a dirt receiving port 13 that opens upward on the pressure chamber 3 side. Further, a downward earth and sand discharge port 14 is formed on the atmospheric pressure chamber 4 side.

A gate 15 for opening and closing is arranged at the earth and sand discharge port 14, and a suction pipe 17 of a squeeze pump 16 is connected to the earth and sand discharge port 14 so as to be freely communicable and detachable.

The suction pipe 17 of the squeeze pump 16 has a face shape or is connected or disconnected depending on the water content of the excavated soil.
For excavated soil with low moisture content, use screw conveyor 1.
Since the earth pressure in the pressure chamber 3 can be maintained only by the pump 1, there is no need to use the squeeze pump 16.

That is, in order to discharge the excavated earth and sand to the atmospheric pressure chamber 4 side while maintaining the earth pressure in the pressure chamber 3, the earth and sand discharge port 14 is closed by the gate 15, and the excavation is carried out while the screw conveyor 11 is operated by the motor 18. When this is done, the excavated earth and sand enters the pressure chamber 3 and the casing 1 of the screw conveyor 11.
It fills up within 2.

Therefore, by repeatedly opening and closing the gate 15, it becomes possible to discharge excavated earth and sand from the discharge port 14 while maintaining the earth pressure in the pressure chamber 3.

On the other hand, the distal end of the discharge pipe 19 of the squeeze pump 16 opens at the atmospheric pressure chamber 4, so that earth and sand can be supplied to the transport vehicle 20.

As is well known, the squeeze pump 16 has one end of an inflatable and deflated transfer pipe as a suction pipe 17, and the other end as a discharge pipe 1.
9, the pipe is squeezed in the middle part and the pipe is transferred by shifting the squeezed position in the transfer direction, and is suitable for transferring earth and sand with a high water content, and this squeeze pump 16 also reduces pressure. Earth and sand can be discharged to the atmospheric pressure chamber 4 while maintaining the earth pressure in the chamber 3.

In this embodiment, the screw conveyor 11 and the squeeze pump 16 constitute an earth removal device.

Reference numeral 21 denotes a discharge port opening/closing valve of the discharge pipe 19.

On the other hand, two branch pipes are connected to the discharge pipe 19 of the squeeze pump 16, and one of the branch pipes 22 is for introducing a part of the discharged earth and sand from the discharge pipe 19 into the mixing tank 23. , the other branch pipe is a backfilling pipe 2 for filling the backfilling material prepared in the mixing tank 23 to the outside of the segment 25 arranged at the rear of the shield excavator main body 1.
4.

That is, in addition to discharged earth and sand, cement, aggregate, water, solvent 26, etc. are introduced into the mixing tank 23, and after being agitated and mixed by an agitator 27, the mixture is sent to the suction pipe 17 of the squeeze pump 16 through the circulation pipe 28. be provided.

Opening/closing valves 29, 30, 31 are interposed in the branch pipe 22, backfilling pipe 24, and circulation pipe 28, and when loading excavated earth and sand onto the transport vehicle 20, the discharge opening opening/closing valve 21 is opened. together with on-off valves 29, 30, 31
keep it closed.

At this time, the on-off valve 29 of the branch pipe 22 may be opened to introduce a portion of the discharged earth and sand into the mixing tank 23.

When filling with backfilling material, the excavation is stopped, the discharge port opening/closing valve 21 and the opening/closing valve 29 of the branch pipe 19 are closed, and the opening/closing valve 3 of the backfilling pipe 24 and the circulation pipe 28 is closed.
0 and 31 to operate the squeeze pump 16, the backfilling material formed in the mixing tank 23 is transferred to the circulation pipe 28, the suction pipe 17, the discharge pipe 19, and the backfilling pipe 24.
It is filled outwardly through segments 1 and 25.

When excavating ground where the soil is sandy and is highly separable from water, the soil removal devices 11 and 16 inject a cement solution into the excavated soil to give it viscosity and lubricity. This is preferable for maintaining performance.

For this reason, in this embodiment, the stirring tank 32 disposed inside the pit,
A cement solution is prepared using an agitator 33 and a pressure pump (mono pump) 34, and is injected into the earth and sand transfer path by the screw conveyor 11 through a pressure pipe 35.

In this case, the injected cement solution is used as part of the backfill material.

36 is a valve. In the embodiment described above, the squeeze pump 16 is used both for discharging earth and sand into the atmospheric pressure chamber and for pumping backfilling material. However, the present invention is not limited to this. A pressure feeding device (pump) may be provided, and in this case there is an advantage that backfilling can be performed simultaneously without stopping excavation.

According to the shield excavator described above, especially when the excavated soil is sandy, the soil types to which the cement solution can be used as a lubricant for the excavated soil and as mortar for backfill material are greatly expanded.

As is clear from the above description, the shield excavator according to the present invention can reuse excavated earth and sand as a backfilling material and perform backfilling quickly, so that it facilitates smooth excavation. It can be done.

[Brief explanation of drawings]

The drawing is an overall vertical sectional side view of a shield tunneling machine according to an embodiment of the present invention. 1... Shield tunneling machine main body, 3... Pressure chamber, 4... Atmospheric pressure chamber, 11... Screw conveyor, 16... Squeeze pump , 22
...Branch pipe, 23...Mixing tank, 24.
...Backfill piping, 25...Segment,
26... Cement, aggregate, water, solvent, etc., 28.
...Circulation pipe.

Claims (1)

[Claims] 1. A shield excavator comprising a pressure chamber filled with excavated earth and sand and holding a face with the soil wall of the earth and sand, wherein the excavated earth and sand is transferred to the atmospheric pressure chamber while holding the earth wall of the pressure chamber. A soil removal device that can be discharged to the side is installed, and a mixing tank is provided to mix the soil discharged from the soil removal device with cement, aggregate, water, solvent, etc. 1. A shield excavation machine, characterized in that a backfilling piping is provided for sending the formed backfilling material to the outside of a segment arranged at the rear of the shield excavation machine main body, and a backfilling material pressure feeding device is connected to the piping.