JPH0633716B2 - Shield drilling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a shield having a face part of an earth pressure excavator using a shield and a device for pumping an appropriate amount of bubbles into a chamber facing the face surface. The present invention relates to a drilling device.

(Conventional technology and its problems) When excavating a sandy soil layer (including a gravel layer) that has been flooded by a shield machine, the stability of the cutting face is attempted to be maintained by filling the chamber of the machine with excavated soil. There is. However, in reality, it is very difficult to keep the excavated earth and sand in the chamber, and it is also difficult to suppress the inflow of groundwater into the chamber. is there. Also, when the chamber is filled with earth and sand with a large internal friction angle, the rotation resistance of the cutter of the excavator becomes large, and in some cases the cutter cannot rotate or it becomes extremely bad, resulting in a remarkable excavation speed. There was a problem of lowering.

Therefore, as a method to prevent the inflow of groundwater into the chamber and to reduce the resistance of the cutter rotation, a mud material (a mixture of water and bentonite, clay minerals such as clay) is injected into the chamber to form excavated soil. By mixing,
The method of making excavated soil muddy to prevent the inflow of groundwater into the chamber and reducing the rotational resistance of the cutter has been conventionally adopted. However, even with this method, it may not be possible to sufficiently prevent water from flowing into the chamber when the water pressure of the face is high or the aquifer containing gravel cannot be sufficiently stopped. In addition, the mud-like mixed soil produced by this method has a high PH, and because of the mud-like shape, it is difficult to dispose of it, which causes secondary pollution of construction due to disposal.

There is also known a method in which a mixed fluid composed of water, a foaming agent and air is supplied into the pressure chamber, and the mixed fluid is mixed with the cut earth and sand to pressurize the face of the face. (Kaisho 50-103129).

However, even with this method, it was not sufficient to prevent the inflow of groundwater from the face, and there was a limit to the stabilization of the face.

(Means for Solving the Problems) The present invention has been made to solve the problems as described above, and sends bubbles that are hard to disappear even if they meet water to the face of the cutter of the shield machine, By invading air bubbles into the ground, it creates a pressured state that is more effective than the normal pressured construction method, prevents groundwater from mixing into the cutting face, stabilizes the cutting face, and also sends bubbles to the chamber by another system. By mixing with the excavated soil, reducing the shearing force of the mixed soil to reduce the rotational resistance of the cutter, and filling the mixed soil in the chamber and screw,
It is intended to further stabilize the face and to impart non-permeability and non-permeability to excavated soil.

That is, for example, according to the experimental results, the gravel content is 82%.
When the foam material is used in the ground, the use of the air bubble amount of about 1/1000 of the air amount used in the normal air pressure construction method has a sufficient air pressure effect.

Further, it is understood that when the masa soil (coarse sand) and the bubbles are mixed at a volume ratio of 1: 0.25, the masa soil of 7 cm of slumb has fluidity such that slamb cannot be measured before mixing. Thus, the mixing of air bubbles significantly reduces the shear resistance of soil.

In addition, if mixed soil mixed with bubbles is transported to the dump site and left there, the bubbles will disappear naturally and the state will return to normal excavated soil. It has the advantage of not worrying.

Therefore, the present invention, as described above, in the face portion of the front face of the cutter of the shield machine, in the foaming device, pre-foamed with the foaming liquid and air, pressure-resistant bubbles that are resistant to water, are more effective than the normal pressure method. A high pressure state is created to stabilize the face, the above-mentioned bubbles resistant to water are pressure-fed into the chamber by another system, and the amount of these bubbles is controlled according to the excavation state of the shield machine. By reducing the rotational resistance of the cutter in the chamber and filling the bubble and mixed soil in the chamber and the screw, the face is further stabilized, and the excavated soil is rendered impermeable and impermeable, and The excavated soil provides a shield excavator that is advantageous from the viewpoint of pollution control because there is no risk of secondary pollution caused by construction even if it is discarded.

(Examples) Examples of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, 1 is ground, 1a is a shaft, 2 (FIG. 1) is a shield machine, 2 '(FIG. 2) is a propulsion shield machine, 3 is a face, 4 is a face. Chamber facing 5
Is a screw earth unloader, 6 (Fig. 1) is a segment, 7
(Fig. 2) is a propulsion pipe. Reference numeral 8 in the drawing denotes a propulsion jack, which is interposed between the shield excavator 2 and the front end face of the segment 6 in the case of FIG. 1, and in the case of FIG. It is arranged so as to propel the rear end portion in the vertical shaft 1a of the propulsion pipe 7 which is connected to the rear portion and arranged. Reference numeral 9 in the figure is an earth discharging conveyor established by being connected to the screw type earth discharging machine 5.

10 is a foaming device, which is provided in the shaft 1a in the case of FIG.
In the case of FIG. 2, it is installed on the ground 1. The foaming device 10 can be installed in the tunnel pit 11 depending on the space. Bubbles are sent from the foaming device 10 through a foaming pipe 12. The foam sending pipe 12 is branched into a face injection pipe 13 and an in-chamber injection pipe 14, and flow rate control valves 15 and 15 'are respectively inserted therein. A bubble pressure detector 16 is attached to the foam sending pipe 12. Further, a cutter pressure detector 17 and a screw discharge pressure detector 18 are attached to the shield machine 2 and the propulsion shield machine 2 '. Reference numeral 19 in the figure is a displacement detector of the propulsion jack 8.

FIG. 3 illustrates a control system diagram of the foaming device 10. The microcomputer 20 controls the amount of bubbles, the opening degree of the gate 5a of the screw type soil unloading machine 5, and the rotation speed of the screw 5b (see FIGS. 1 and 2). Reference numeral 21 is a block having a statistical processing function for each data entered into the microcomputer 20. Reference numeral 22 is a signal amplifier of the face bubble pressure P by the bubble pressure detector 16, and 23
Is a tank of bubbly liquid.

FIG. 4 is a circuit block diagram showing an example of the foaming mechanism of the foaming device 10, 20 is the microcomputer, 24
Is a signal that converts each signal from analog to digital
A / D converter, 25 is a D / A for converting a digital signal output from the microcomputer 20 into an analog signal
The converters 26, 26 'are electronic shutoff shift control panels for bubble liquid and air, and 27, 27' are periodic rotation proportional control motors for bubble liquid and air, respectively. Also 28,
Similarly, 28 ′ is a clutch brake for air bubble liquid and air, and is a brake device for limiting the upper and lower limits of the face air bubble pressure P. Numeral 29 is a variable pump, and its liquid delivery pipe 3
A check valve 31 is inserted at 0. 32 is a compressor, and the air from this compressor 32 is an air supply pipe 33.
To the foam tube 34, where it is mixed with the bubble liquid to form air bubbles, and the bubbles are fed into the mine by the bubble pipe 12 as described above.

As the foaming liquid to be used by putting it in the above-mentioned bubble liquid tank 23, a surfactant added with a superabsorbent polymer or a protein-based foaming agent is suitable. For example, polyoxyethylene alkylphenol ether Escort L (trade name) whose main component is sodium sulfate, and super absorbent polymer, for example, Sumika gel (trade name) whose main component is vinyl alcohol acrylate copolymer, or whose main component is sodium polyacrylate Examples include those to which Aqua Keep (trade name) is added, and Escort K (trade name) whose main component is partially hydrolyzed protein.

Next, an example of a construction method using the device of the present invention configured as described above will be described. In this construction method, during excavation, the variable pump 29 is driven to send the bubbling liquid in the bubbling liquid tank 23 to the bubbling pipe 34, and at the same time, the compressor 32 feeds the air feeding pipe 33.
Air is sent to the foaming pipe 34 through the foam to foam, and the foamed air bubbles are shielded by the foaming pipe 12;
Face 3 on the front face of the cutter of the propulsion shield machine 2 ',
And into the chamber 4. By doing so, a compressed air state that is more effective than the normal compressed air method is created, and the face 3 can be stabilized. In addition, the rotation resistance of the cutter in the chamber 4 can be reduced, and the bubble 4 is filled in the chamber 4 and the screw excavator 5 to further stabilize the face 3, The excavated soil can be made impermeable. Also, if the mixed air and sand is left in the dumping place, the air bubbles will naturally disappear and it will be the same as normal excavated sand and sand, so there is no risk of pollution problems.

Further, in this method, each data of face bubble pressure, cutter pressure, screw earth pressure and excavation speed during shield excavation is instantly collected in the microcomputer 20 and statistically analyzed to obtain the analysis result. Based on the control of the amount of bubbles pressed into the face 3 on the front face of the cutter and the amount of bubbles pressed into the chamber 4, the number of revolutions of the screw 5b of the screw earthing machine 5 and the opening of the gate 5a are also controlled. The bubble pressure can be kept constant, and the rotational resistance of the cutter can be adjusted to an appropriate level to control so as to create an optimum excavation state.

That is, the face air bubble pressure detector 16, the cutter pressure detector 17, and the screw discharge pressure detector 18 detect the respective pressures, and the displacement by the propulsion jack 8 is detected by the displacement detector 19, and these output signals are A / A / D with D converter 24
The data is converted and sent to the microcomputer 20, the data is statistically analyzed, and the optimum control signal is sent to the electronic unauthorized conversion controller 26, 26 'through the microcomputer 20 based on the analysis result. Is used to change the number of revolutions of the periodic rotation proportional control radars 27 and 27 'to control the discharge amount of the variable pump 29. At the same time, by controlling the amount of air from the compressor 32, the amount of bubbles generated from the foam tube 34 and the mixing ratio of the amount of bubble liquid and the amount of air can be changed and adjusted to an optimum value.

The bubbles sent from the foaming pipe 34 through the foaming pipe 12 are diverted into the face injection pipe 13 and the injection pipe 14 into the chamber 4, and the bubbles are generated by controlling the flow control valves 15 and 15 ′ with the microcomputer 20. It is possible to control the rotational resistance of the cutter by adjusting the amount, keeping the bubble pressure of the face constant. Furthermore, in order to make these adjustments precise, the rotation speed of the screw 5b and the opening of the gate 5a of the screw excavator 5 can also be controlled to create an optimum excavation state.

(Effect of the invention) Since the device of the present invention is as described above, according to this device, a compressed air state that is more effective than the normal compressed air construction method is created, the face is stabilized, and the rotational resistance of the cutter in the chamber By improving the excavation performance and filling the mixed soil in the chamber and the screw, it is possible to obtain an effect that the face can be further stabilized. Further, since the excavated soil can be made impermeable and it is not necessary to treat the excavated soil as industrial waste, the present invention has an excellent effect that it is very advantageous in terms of pollution control.

[Brief description of drawings]

1 and 2 are vertical sectional views showing the excavated state of the ground by the method of the present invention. FIG. 3 is a schematic diagram showing a control system of the foaming device, and FIG. 4 is a schematic diagram showing a structure of the foaming device. 1 ... Ground 1a ... Vertical shaft 2 ... Shield excavator 2 '... Propulsion shield excavator 3 ... Face face 4 ... Chamber 5 ... Screw excavator 6 ... Segment 7 ... Propulsion pipe 8 ... … Propulsion jack 9 …… Soil removal conveyor 10 …… Foaming device 11 …… Tunnel mine 12 …… Bubbling pipe 13 …… Face injection pipe 14 …… Chamber injection pipe 15 …… Mud volume control valve (cut face side) 15 '... Flow control valve (inside chamber) 16 ... Face bubble pressure detector 17 ... Cutter pressure detector 18 ... Screw discharge pressure detector 19 ... Displacement detector 20 ... Microcomputer 21 ... Data Block having processing function 22 ... Amplifier 23 ... Bubbling liquid tank 24 ... A / D converter 25 ... D / A converter 26 ... Electronic cutoff shift controller (for bubbling liquid) 26 ...... Electronic cut-off shift controller (for air) 27 ...... Periodic rotation proportional control motor (for air bubble liquid) 27 '...... Periodic rotation proportional control motor (for air) 28 ...... Clutch brake (air bubble liquid side) 28' ...... Clutch brake (air side) 29 …… Variable pump 30 …… Liquid supply pipe 31 …… Check valve 32 …… Compressor 33 …… Air supply pipe 34 …… Bubbling pipe 35 …… Bubbling pipe.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-50-103129 (JP, A) JP-A-57-29792 (JP, A)

Claims (1)

[Claims] 1. A foaming device is provided in association with a shield machine, and air bubbles previously foamed by a foaming liquid and air by the foaming device are sent under pressure to the face face of the shield machine and also separately in the chamber. A shield excavation device comprising: a bubble pumping mechanism for pumping bubbles in a system; and a control mechanism for controlling the bubble sending amount of these bubbles according to the excavation state of the shield machine.