JPS5916077B2 - Confining mud water shield excavator - Google Patents

Description

[Detailed description of the invention] The present invention relates to a confining mud water shield excavator.

The following shield construction methods are known for constructing tunnels under ground where groundwater pressure is high and there are many springs, while preventing the intrusion of groundwater.

Firstly, the limited pressure air construction method involves installing a sealed bulkhead in the front ward and injecting pressurized air into the pressurized chamber between the front faces to prevent groundwater from entering.Secondly, the soil conditions include soft geology. This is a muddy water processing method that uses pressurized circulation to inject muddy water to prevent groundwater from entering and preventing the face from collapsing.

In the above-mentioned limited pressurized air method, the density of the pressurized air that prevents the intrusion of groundwater is very low, and the volume of the limited pressurized chamber is small. Not only is it difficult to prevent air leakage, but the pressure in the pressurized chamber often fluctuates due to the influence of air leakage.

In addition, the level of pressure applied to the face by air may cause problems such as collapse of the face and blow-through of pressurized air related to the dehydration properties of the face, so there is a problem that excessive pressure cannot be applied to suppress groundwater. there were.

On the other hand, in the muddy water pressurization method, the medium used for pressurization is muddy water itself, which has a high density and specific gravity.
This is a very rational deterrent measure that can effectively prevent the face from collapsing depending on the concentration of muddy water.

However, in this construction method, when excavated soil is taken out from the pressurized chamber, the excavated soil is stirred into a slurry in the pressurized chamber, the slurry is transported to an above-ground mud water separator, the soil is separated and discharged, and the separated water is recycled again. Mud water treatment equipment installed on the ground requires a large amount of space because it uses a water pump to circulate and inject water under pressure.In addition, it requires management of the concentration of sludge and its equipment, as well as pressure control management related to the amount of sludge and water delivered. Furthermore, these facilities were complex and expensive, and required even more sophisticated management techniques.

This invention was devised to solve the above-mentioned conventional problems, and the muddy water for pressurizing and suppressing the face is sealed in the pressurizing chamber without being circulated, and the excavated earth and sand is turned into slurry. To provide a confining mud water shield excavator capable of safely taking out the excavated earth itself from a pressurizing chamber directly to the rear of the excavator while preventing the overflow of pressurized mud water without overflowing.

The present invention will be described in detail below based on the accompanying drawings.

In FIG. 1, 1 is the main body of the confining mud water shield excavator (hereinafter referred to as the shield main body).

), and the sealing partition wall 2 provided in front of this shield body 1 was installed at the rear of the sealing partition wall 2.

A drum cutter 4 for face cutting, which is rotationally driven by a drive device 3, is supported via a sealed bearing 5.

The drum cutter 4 is formed into a conical shape, and the tip of the casing 7 of the screw conveyor 6 inserted from the machine side is attached to the center of the drum cutter 4 in a watertight manner and relatively freely rotatable.

The upper part of the tip of the casing T protruding inside the drum cutter 4 is open, and this open part? As shown in FIGS. 2 and 3, a hopper 9 of the earth and sand receiver supported by four vertically movable columns 8 is installed so as to be movable up and down with respect to the opening 7a of the casing 7.

As shown in FIG. 4, the vertically movable column 8 has a column outer cylinder 11 attached to the side wall of the hopper 9 via a bracket 10, and an inner column attached to the side of the casing 7 via a bracket 12. A load cell 14 (load detection device) for detecting the amount of earth and sand (load) loaded onto the hopper 9-hi is housed inside the support inner cylinder 13.

Moreover, a rod 15 that supports the hopper 9 is installed in the upper part of the load cell 14.
When a predetermined weight of excavated earth and sand is loaded inside, the load cell 14 detects the weight via the rod 15.

The load cell 14 is associated with the drive motor 16 of the screw conveyor 6 provided at the rear end of the casing 7, and when the load cell 14 detects a predetermined weight of earth and sand, it drives the first drive motor 16 and stops rotating when the load cell 14 detects a predetermined weight of earth and sand. It is configured to stop.

A discharge hopper 18 is provided at the rear lower part of the casing 7 to discharge the excavated soil transferred by the screw conveyor 6 to the rear of the machine side. It is equipped with a discharge gate 20 that opens and closes.

Further, 21 indicates blades for moving earth and sand provided at predetermined intervals on the inner wall of the drum cutter 4, and 22 indicates a shield jack provided at the rear of the sealing partition wall 2.

Next, in the muddy water pressurizing chamber 23 defined between the sealed bulkhead 2 and the face The pressure pipe 25 projects from the pressure pipe 25 to seal the muddy water in the muddy water pressurizing chamber 23 so as to keep it at a constant pressure at all times.

Next, the operation of this invention will be explained.

First, in the initial stage of shield excavation, in order to set the mud water pressure chamber 23 to a predetermined mud water concentration pressure, mud water of a predetermined concentration is poured into the mud water pressurization chamber 23 from the excavator side through the pressure pipe 25 that penetrates the sealed bulkhead 2. Inject into 23.

Thereafter, the pressurizing pipe 25 is communicated with the head tank 24 installed at a predetermined height position in the starting shaft a, and the head tank 24 maintains the water level of the groundwater level + α, so that the mud water inside the pressurizing chamber 23 is maintained at a constant pressure. Contain muddy water.

From this state, the drive device 3 is driven once to cause the drum cutter 4 to start cutting the face.

The face earth and sand cut by the drum cutter 4 is rotatably transferred upward in the mud water pressurizing chamber 23 by the earth and sand transfer blade 21 provided on the drum cutter 4, and from there, the earth and sand provided in the casing 7 is transferred by the gravity of the earth and sand. The receiver falls and accumulates in the hopper 9.

In this way, when a predetermined weight of excavated soil is loaded into the hopper 9, the first drive motor 16 of the screw conveyor 6 starts rotating in response to a detection instruction from the load cell 14, and the soil receiver is moved into the hopper 9. Only the earth and sand that has been piled up and consolidated into earth and sand plugs is sequentially conveyed rearward by the screw conveyor 6.

Therefore, since the compressed mud water in the mud water pressurizing chamber 23 covers the blades of the screw conveyor 6 with the compacted excavated earth deposited in the hopper 9, water cannot overflow from the gap between the screw conveyor 6 and the casing 7. There is no.

When the amount of earth and sand in the hopper 9 decreases due to the drive of the screw conveyor 6, the load cell 14 detects this, the drive motor 16 stops, and the earth and sand receiver waits until a predetermined amount is deposited again.

The earth and sand forced to the rear of the excavator by the screw conveyor 6 is sent to a discharge hopper 18 provided at the rear lower part of the casing 7.
When the discharge hopper 18 is filled with earth and sand, the jack 19 is driven to open the discharge gate 20 and the excavated earth and sand are discharged to the rear of the machine.

The highly concentrated muddy water required to prevent the face from collapsing can be obtained by dissolving the clay shield material that gets mixed in when the face is excavated. There is no need to adjust the concentration of muddy water in order to manage the resistance inside the pipe, and therefore the muddy water can be left as a highly concentrated muddy water, making its management much easier.

As described above, this invention fills a muddy water pressurizing chamber with muddy water of a high concentration sufficient to prevent the collapse of the face, and pressurizes the muddy water with a water head difference equivalent to the groundwater level. The earth and sand receiver provided at the top of the tip of the screw conveyor sequentially loads the earth and sand into the hopper, and when the earth and sand is loaded into the hopper in excess of a predetermined amount, the earth and sand receiver activates the drive motor of the screw conveyor via a load detection device. The rotary operation is controlled, and the earth and sand receiver only transports only the earth and sand frames made up in the hopper to the rear of the excavator using a screw conveyor, so it is possible to use mud water treatment equipment for mud water circulation like in the conventional mud water pressurization method. It does not require a large space, and since muddy water is not turned into slurry, there is no need for waste water concentration management, waste water volume, pressure control management and related equipment related to water flow, resulting in cost savings and advanced management technology. This has the effect of allowing excavation work to be carried out safely and efficiently without the need for.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of the confining mud water shield excavator of the present invention, Fig. 2 is an enlarged side view showing the hopper of the earth and sand receiver in Fig. 1, and Fig. 3 is a longitudinal sectional front view of Fig. 2. FIG. 4 is a longitudinal sectional view of the vertically movable support column. 1... Shield body, 2... Sealed bulkhead, 3... Drive device, 4... Drum cutter, 5... Sealed bearing, 6... Screw conveyor, 7... Casing, 7a...
... Open part, 8 ... Vertically movable column, 9 ...
...The earth and sand catcher is a hopper, 10...Bracket,
11... Support outer cylinder, 12... Bracket, 13... Support interior, 14... Load cell, 15... Rod, 16...・・・・・・、
Drive motor, 17...Lead wire, 18...
...Discharge hopper, 19... Jacket, 20...
...Discharge gate, 21...Blade, 22
...Shield jack, 23...Mud water pressurization chamber, 24...Head tank, 25...
...Pressure pipe, a...Starting shaft, X...
Face.

Claims (1)

[Claims] 1 A muddy water pressurization chamber defined through a sealed bulkhead in the front part of the shield tunneling machine body is filled with highly concentrated muddy water and pressurized independently to a water head difference equivalent to the groundwater level, and the muddy water pressurized chamber is filled with high concentration muddy water. In addition to installing a drum cutter with a rotatable face,
At the center of this drum cutter, a screw conveyor casing with an upper tip opening into a muddy water pressurizing chamber is installed in a watertight manner, and a hopper is installed at the tip of the casing via a vertically movable column. The earth and sand receiver is provided with a load detection device for detecting the weight of earth and sand loaded into the hopper on the vertically movable support, and furthermore, the earth and sand receiver is equipped with a load detection device that detects when a predetermined amount or more of excavated earth and sand is loaded in the hopper. A confining mud water shield excavator characterized by being equipped with a drive motor that rotates and drives a screw conveyor only when the screw conveyor is detected.