JPS59213897A - Shield drilling apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shield excavator having a device for pumping an appropriate amount of air bubbles into a face portion at the front of a Tonosho type excavator using a shield and a chamber facing the face surface.

Conventionally, when excavating a water-logged sandy soil layer (including a gravel layer) with a shield excavator, the stability of the face has been maintained by filling the chamber of the excavator with excavated soil. However, in reality, it is extremely difficult to create a condition in which the chamber is filled with excavated soil, and it is also difficult to prevent groundwater from flowing into the chamber, resulting in low stability of the face and the tendency to collapse. In addition, if the chamber is filled with earth and sand with a large internal S friction angle, the rotational resistance of the cutter of the excavation machine will increase, and in some cases, the rotation of the cutter will become impossible or extremely slow, resulting in a decrease in the excavation speed. There was a problem in that the value decreased significantly.

One way to prevent groundwater from flowing into the chamber and reduce the resistance to cutter rotation is to inject muddy material (a mixture of water and clay minerals such as bentonite and clay) into the chamber, and mix it with excavated soil. Conventional methods have been used to prevent underground water from flowing into the chamber by mixing the excavated soil into a slurry and reduce the rotational resistance of the cutter, but when the water pressure at the face is high or In the case of an aqueous layer containing cobbles, it may not be possible to sufficiently stop the water, and it may not be possible to prevent groundwater from flowing into the chamber.

In addition, the muddy mixed soil produced by this method has a high pH and is muddy, making disposal difficult and causing secondary construction pollution.

The present invention was made to solve the above-mentioned problems.
Air bubbles that do not disappear even when exposed to water are sent to the front of the cutter of the shield excavator, and the air bubbles penetrate into the ground, creating a pressurized air condition that is more effective than the normal pressurized air construction method and preventing groundwater from flowing into the face. In addition to preventing and stabilizing the face, air bubbles are also injected into the chamber using a separate system to mix with the excavated soil, reducing the shear force of the mixed soil and reducing the rotational resistance of the cutter. By filling the chamber and screw with the mixed soil, the face is further stabilized, and the excavated soil has low water permeability and low air permeability.

According to experimental results, when foam material is used on ground with a sand and gravel content of 82%, the amount of air used in the normal pressure air construction method is approximately 100%
It had a sufficient pressure effect even when used for 1/0 of a bubble.

In addition, the volume Jt of masa ± (coarse sand) and air bubbles is 1:
It was found that when mixed at a ratio of 0.25, MAV soil with a slump of 7 cm had such fluidity that it was impossible to measure the slump before mixing. In this way, the mixing of air bubbles dramatically reduces the soil resistance.

J: If the mixed soil mixed with air bubbles is transported to a soil dumping site and left alone, the air bubbles will naturally disappear and return to the normal excavation condition. It has the advantage of not having to worry about pollution.

As described above, the present invention stabilizes the face by sending air bubbles that are resistant to water to the front of the cutter of the shield excavator to create a pressure state that is more effective than the conventional pressure method. The system sends air bubbles that are resistant to water into the chamber, reducing the rotational resistance of the cutter in the chamber, and filling the chamber and screw with this mixed soil, which further stabilizes the face and improves the stability of the excavation surface. The purpose of the present invention is to provide a shield excavation device which is advantageous from a pollution control point of view, which provides low water permeability and low air permeability to the ground, and eliminates the risk of secondary construction pollution even if the scraped soil is disposed of. It is something.

The present invention will be described in detail below with reference to the drawings.

In the figure, 1 is the ground, 1a is the shaft, 2 (see Figure 1) is the shield tunneling machine, 2' (see Figure 2) is the shield tunneling machine for propulsion, 3 is the face, and 4 is the chamber facing the face. , 5
is a screw earth remover, 6 (see Figure 1) is a segment,
7 (see Figure 2) is a propulsion pipe, 8 is a propulsion jack, and the first
In the case shown in the figure, the propulsion pipes 7 are installed between the front ends of the excavator 2 and the segment 6, and in the case of FIG. It is arranged so as to promote it. Further, 9 is an earth removal conveyor connected to the screw set earth removal machine 5. -10 is the foaming device e1 installed in the shaft 1a in the case of FIG. 1, and installed on the ground 1 in the case of FIG.

Moreover, depending on the space, it can also be installed in the tunnel tunnel 11. Bubbles are sent from the foaming device 10 by a foaming vibrator 12, and this vibrator 12 is branched into a face injection vibe 13 and a chamber injection pipe 14, each of which has a flow control valve 15, 15' inserted. A face bubble pressure detector 16 is attached to the injection pipe 13 . The shield excavator 2.2' has a cutter pressure detector 11 and a screw discharge pressure detector 18. 19 is a displacement detector of the lit advance jack 8.

FIG. 3 shows a control system diagram of the foaming device 100, in which the microcomputer 20 controls the amount of bubbles and the screw set n1.
The opening degree of the gate 5a of the earthen machine 5 and the rotation speed of the screw 5b (see Fig. 1.2) are controlled. Reference numeral 21 denotes a block having a t1 processing function for each data input to the microcomputer 20. 22 is face bubble pressure detector 1
6 is an amplifier for the signal of the face bubble pressure P, and 23
is a tank of bubble liquid.

FIG. 4 is a circuit block diagram showing an example of the foaming mechanism of the foaming device 10, in which the microcomputer 124 is an A/D converter that converts each number 13 from an analog signal to a digital signal, and 25 is a microcomputer. Converts the output digital signal into an analog signal []/A converter, 26
．． 26' is electronic variable speed control OII board, 27.27'
28, 28' is a synchronous rotation proportional control motor, and 28, 28' is a clutch brake, which is a braking device for limiting the upper and lower limits of the face bubble pressure P. Reference numeral 29 denotes a variable pump, and a check valve 31 is inserted into the liquid feeding pipe 30 of the variable pump. 32 is a compressor, and the air from this compressor 32 is sent to the foaming tube 34 via the air supply pipe 33, where it is mixed with the foam liquid to create air bubbles, and the air bubbles are sent into the mine by the bubble vibrator 12. .

The foaming liquid used in the tank 23 is suitably a surfactant with a superabsorbent polymer added thereto, or a protein-based foaming agent, such as polyoxyethylene alkylphenol ether sulfate 1 - Sumikagel (trade name), which consists of Esko 1-L (trade name) whose main component is Rium, and a super absorbent polymer such as vinyl alcohol acrylate copolymer, or
Examples include those to which Aqua Keep (trade name), whose main component is sodium polyacrylate, and Varnish Coat K (trade name), which has partial H1R water-splitting protein as its main component.

Next, an embodiment of the construction method using the apparatus of the present invention constructed as described above will be described. During excavation, this construction method drives the variable pump 29 to send the foaming liquid in the C tank 23 into the foaming tube 34, and at the same time, the compressor 32 sends air through the air pipe 33 to the foaming tube 34 to foam it, resulting in strong foaming. Air bubbles are sent to the face 3 in front of the cutter of the excavator 2.2' and the inside of the bubble 7 member 4 using the bubble-feeding vibrator 12. send to. In this way, a more effective pressurized air condition is created than with the normal pressurized air construction method, and the face 3 can be stabilized. In addition, it is possible to reduce the rotational resistance of the cutter in the chamber 4, and also to avoid reducing the rotational resistance of the cutter in the chamber 4.
By filling the hole 5, it is possible to further stabilize the face 3 and to provide a state of low air permeability on the excavation. In addition, if this air bubble mixed soil is left in a soil dumping site, the air bubbles will naturally disappear and it will become similar to ordinary excavated soil, so there is no risk of causing the pollution countermeasure-F problem.

In addition, in this construction method, data on face bubble pressure, cutter pressure, screw earth removal pressure, and excavation speed are collected by the microcomputer 20 at any time during shield excavation.
These are analyzed statistically, and based on the analysis results, the amount of air bubbles injected into the cutter face 3 and into the chamber 4 are controlled, and the rotation speed of the screw earth remover 5 and the amount of air bubbles injected into the chamber 4 are controlled. By controlling the opening degree, the face bubble pressure can be kept constant, and the rotational resistance of the cutter can be moderated to create an optimal excavation state.

1, each pressure is detected by a face bubble pressure detector 16, a cutter pressure detector 17, a scrico 111 and a soil pressure detector 18, and the displacement caused by the propulsion jack 8 is detected by a displacement detector 1.
9, and these output signals are A/D converter 24.
/D conversion and sent to the microcomputer 20, these data are statistically analyzed, and based on the analysis results, an optimal control signal is sent to the electronic variable speed control panel 26.26 via the microphone computer 20. ', thereby changing the rotational speed of the synchronous rotation proportional control motor 21, 27' to control the discharge amount of the variable pump 29, and also controlling the amount of air from the compressor 32. The amount of bubbles generated and the mixing ratio of the amount of bubble liquid and the amount of air can also be changed to adjust them to appropriate values.

In addition, air bubbles are sent from the foaming tube 34 by the foaming vibrator 12 [
Then, the flow is divided into the injection vibe 13 at the face and the injection vibe 14 into the chamber 4, and the flow rate control valves 15 and 15' of each are controlled by the microcomputer 20 to control the amount of bubbles raw and keep the bubble pressure at the face constant. The rotational resistance of the cutter can also be controlled. Furthermore, in order to make these adjustments more precise, the rotational speed and opening degree of the Scrico-T IJI earth machine 5 can also be controlled to create an optimal excavation state.

As described above, the device of the present invention creates a pressurized air condition that is more effective than the normal pressurized air method, stabilizes the face, and reduces the rotational resistance of the cutter in the chamber to allow excavation. By improving performance and filling the chillen bar and scrico with mixed soil, the effect of further stabilizing the face can be obtained. In addition, since the excavated soil can be covered with air-impermeability, there is no need to treat the excavated soil with industrial waste, so the present invention has an excellent effect in that it is advantageous for non-electronics in terms of pollution control. is obtained.

[Brief explanation of the drawing]

Figures 1 and 2 are elevational views showing the state of ground excavation by the device of the present invention, Figure 3 is a schematic diagram showing the control system of the foaming equipment, and Figure 4 is a schematic diagram showing the configuration of the foaming equipment. be. 1...Ground 1a...Shaft 2...Shield excavator 2'...Propulsion shield excavator 3...Face surface 4...Chamber 5...
Screw earth remover 6...Segment 7...Propulsion pipe 8...t
Ii Shinji V Tsuki 9...Earth removal conveyor 10.
...Foaming device 11...Tunnel underground 12...
- Foaming pipe 13... Face injection pipe 14...
・Chamber injection pipe 15...Flow rate control valve (face side) 15'...Flow rate control valve (inside the chamber) 16...Face bubble pressure detector 17...Cutter pressure detector 18...Screw Discharge pressure detector 19...Displacement detector 20...Microcomputer 21...Block 2 having data processing LrptfM function
2... Amplifier 23... Bubbly liquid tank 24
...Δ/D converter 25...D/Δ converter 26.
...Electronic variable speed control m<bubble liquid amount) 26'Electronic variable speed control panel (air amount) 27...Synchronous rotation proportional control motor (bubble liquid ■)27'Synchronous rotation proportional control motor (air m ) 28...Clutch brake (bubble liquid amount) 28'.
...Clutch brake (air side) 29...Variable pump 30...Liquid feed pipe 31...Check valve 3
2...Kombutsusa 33...Air pipe 3
4... Foaming pipe 35... Foaming pipe.

Claims (1)

[Claims] 1. A foaming device is attached to the shield tunneling machine, and the bubbles generated by this foaming device are forced to the front face of the shield tunneling machine, and the bubbles are also forced into the chamber. A shield excavation device characterized in that the amount of bubbles sent can be controlled according to the excavation state of the shield excavation machine.