JP2770213B2 - Apparatus and method for detecting harmful gas in face by shield method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a means for detecting harmful gas generated from ground in a shield method.

[0002]

2. Description of the Related Art Today, an earth pressure shield method, a muddy water pressure shield method, and the like are widely used to install tunnels such as a subway, water and sewage, and a power communication cable in an underground space of a city. With the shield method, a shaft is built, a strong steel shell called a shield is inserted into the ground from the shaft, the ground is cut in front of the space protected by the shield, and segments are assembled at the rear. This is a construction method in which the tunnel is expanded by moving the shield forward while allowing the segment to react.

The underground where the above-mentioned shield method is constructed is under conditions where it is difficult to supply outdoor fresh air sufficiently. Therefore, when harmful gas such as flammable gas such as methane gas is generated from the ground, there is a system that can quickly detect the harmful gas and notify the user of danger such as oxygen deficiency or explosion. It is essential.

Accordingly, a method has been adopted in which a check boring is performed from the ground before a shield reaches above a route where a tunnel is to be constructed by a shield method. In addition, a method has been adopted in which a gas detector is installed in a shield machine to measure the gas concentration.

[0005]

However, the check boring method has a problem in that it is not possible to grasp in real time the harmful gas generation state at the face where the construction is actually being performed. Further, since only a few places are checked, the inspection method is incomplete, and there is a problem that a boring cost is required.

Further, the method of measuring the gas concentration using a gas detector installed in a shield machine is a method in which a hazard is detected only after a harmful gas flows into the rear of the bulkhead of the shield machine. However, it is not possible to grasp in real time the status of harmful gas generation at the face, and it is difficult to say that this method is completely safe for humans working in the mine.

[0007] Accordingly, an object of the present invention is to provide means capable of quickly detecting harmful gas generated from the ground in a mine where the above-mentioned shield method is constructed.

[0008]

According to the present invention, a supply pipe is formed for guiding ground sediment in the ground where the shield method is performed to a deaeration chamber in a state of muddy water. Forming an exhaust pipe for transporting the degassed gas to the harmful gas detector, and further providing a harmful gas treatment device downstream of the exhaust pipe detector; A gas detection device is provided.

This detection device further has the following features. -Provide a pre-filter for collecting coarse particles in muddy water upstream of the degassing chamber in the supply pipeline.・ A pump is provided in the exhaust pipe to transport the gas degassed from the muddy water in the degassing chamber to the harmful gas detector.

According to the present invention, the following method is provided as a harmful gas detection method using the above-described detection device. -In the earth pressure shield method, a sampling pipe is formed at the back of the bulkhead to circulate the earth and sand taken into the cutter chamber into muddy water, and the muddy water circulating through the sampling pipe is led to the degassing chamber to be harmful. A harmful gas detection method configured to detect the presence or absence of gas. -A harmful gas detection method in which a part of mud discharged by a drain pipe is guided to the above-mentioned degassing chamber to detect the presence or absence of harmful gas in the muddy pressure shield method.・ In the face of the shield method, a horizontal boring is drilled in the direction to be cut from now, and the cutting soil near the tip of the horizontal boring is made muddy and guided to the deaeration chamber to detect the presence of harmful gas. Detection method.

[0011]

[Effect] The earth and sand cut at the face is made muddy and guided from the supply pipe to the deaeration chamber. The gas degassed from the muddy water in this degassing chamber is transported to a harmful gas detector through an exhaust pipe. Here, when a harmful gas is present, it is detected as dangerous by the detector. Then, the harmful gas is further conveyed to a harmful gas treatment device provided downstream of the detector through an exhaust pipe, and is appropriately treated. On the other hand, the mud from which the gas has been degassed is carried out again to the cutter chamber, the mud pipe, and the like. Thus, according to the present invention, the generation of harmful gas such as methane gas at the face is detected in real time,
Danger can be avoided beforehand.

[0012]

Embodiments of the present invention will be described below. FIG.
FIG. 1 shows a block diagram of a detection device A according to an embodiment of the present invention. 1 is a supply line, 2 is its inlet, and 3 is its outlet. As will be described later, the inlet 2 and the outlet 3 are open to a sampling pipe 27 or a drain pipe 35 through which the earth and sand cut at the face is made muddy and circulate. A pre-filter 5 and a deaeration chamber 6 are provided in the supply line 1.
Is provided. The pre-filter 5 has a diameter of 200, for example.
A filter for collecting coarse particles of μm or more, which collects coarse particles contained in the muddy water before the muddy water is carried into the degassing chamber 6 and infiltrates the coarse particles into the degassing chamber 6. Hinders As the prefilter 5, for example, "Stellapore H" manufactured by Mitsubishi Rayon Co., Ltd., which is an ultra-precision filtration filter using a polyethylene porous hollow fiber membrane (EHF),
“Stellapore J”, “Stellapore K”, “Stellapore Q” (“Stellapore” is a registered trademark) and the like can be used. An exhaust pipe 7 is connected to the deaeration chamber 6. As the degassing chamber 6, for example, a three-layer composite hollow fiber membrane (MH) having a structure in which a special function ultra-thin film having no pores in an intermediate layer is sandwiched between porous membranes.
A module using F), "Degassing membrane module" manufactured by Mitsubishi Rayon Co., Ltd. can be used. A pump 8, a harmful gas detector 10, and a harmful gas processing device 11 are provided in the exhaust pipe 7.

Thus, according to the above, the earth and sand cut at the face of the shield method is turned into muddy water and supplied to the sampling pipe 27 or the supply pipe through the suction port 2 opened to the drain pipe 35. It is supplied to the path 1 and is carried into the deaeration chamber 6. Since the pre-filter 5 is provided, coarse particles having a diameter of, for example, 200 μm or more contained in muddy water cannot enter the degassing chamber 6.

In the deaeration chamber 6, gas components contained in the muddy water are deaerated. The gas degassed from the muddy water in the degassing chamber 6 is carried into the harmful gas detector 10 through the exhaust pipe 7 by the suction operation of the pump 8. Here, when a harmful gas such as methane gas is present in the carried-in gas, the detector 10 detects that the gas is dangerous. Then, the harmful gas is further conveyed to a harmful gas processing device 11 provided downstream of the detector 10 through the exhaust pipe 7 and is appropriately processed.

On the other hand, the mud from which the gas has been degassed in the deaeration chamber 6 passes through the supply pipe 1 as it is, and is again discharged from the discharge port 3 to the sampling pipe 27 or the drain pipe 35. Therefore, according to the detection device A described above, generation of harmful gas such as methane gas at the face can be detected in real time, and danger can be avoided before it occurs.

Next, the detection device A configured as described above
A method of detecting harmful gases when the method is applied to the earth pressure shield method will be described.

As shown in FIG. 2, a cutter 21 is mounted in front of the shield machine 20, and a cutter chamber 22 is provided behind the cutter 21. In addition, at substantially the center of the cutter chamber 21, an earth discharging conveyor 23 having an outlet at a tail portion of the shield machine 20 is provided.
Cutter chamber 22 and downhole are bulkhead (partition) 2
Blocked at 5. The bulkhead 25 is a facility that shuts off the pressure side of the face and the atmosphere side of the pit.

A cutter bit is attached to the front surface of the cutter 21, and the cutter 21 is rotated to cut the ground and the earth and sand is taken into the cutter chamber 22. Then, while using the cut earth and sand to oppose the pressure of the face, an amount of earth and sand which is balanced with the propulsion amount of the shield machine 20 is continuously fed on the belt conveyor 26 by the earth discharging conveyor 23 provided in the cutter chamber 22. The basic principle is that the shield machine 20 is propelled while the face is stabilized by discharging the soil.

In the above-mentioned earth pressure shielding method, a sampling pipe 27 for circulating the earth and sand taken into the cutter chamber 22 in a muddy state is formed at the back of the bulkhead 25, and is formed in the middle of the sampling pipe 27. Is provided, and the inlet 2 and the outlet 3 of the supply pipe 1 are opened to the sampling pipe 27. Although not shown, in the middle of the sampling tube 27,
A water supply nozzle is provided for turning earth and sand cut at the face into muddy water. Further, in order to make the highly viscous muddy water flow smoothly, a part or the whole of the sampling pipe 27 may be constituted by a snake pump.

In the case where the detecting device is applied to the earth pressure shield method as described above, the gas generated at the face is taken into the cutter chamber 22 together with the earth and sand cut by the face, and the bulkhead is removed. 25 penetrates into a sampling tube 27 formed on the back of the device 25. A water supply nozzle (not shown) is provided in the middle of the sampling pipe 27, and muddy water containing gas is produced inside the sampling pipe 27 by mixing the water supplied from the nozzle with earth and sand. The mud is circulated and circulated through the sampling pipe 27 by operating a snake pump or the like. The mud circulated through the sampling pipe 27 in this way enters the supply pipe 1 of the detection device A provided in the middle of the sampling pipe 27, and reaches the deaeration chamber 6 of the detection device A. Thus, the gas components contained in the muddy water are degassed in the degassing chamber 6, and the gas is carried into the harmful gas detector 10 through the exhaust pipe 7. When a harmful gas such as methane gas is present in the carried-in gas, it is detected by the detector 10 as dangerous, and the harmful gas is further transported to the processing device 11 and is appropriately processed. Is done.

Next, a method for detecting harmful gas when the detection device A is applied to the muddy water pressure shield method will be described.

As shown in FIG. 3, a cutter 31 is mounted in front of the shield machine 30, and a cutter chamber 32 is provided behind the cutter 31. The cutter chamber 32 is provided with a sludge pipe 33 and a sludge pipe 35 connected to a muddy water treatment facility provided on the ground. Then, when cutting underground, muddy water sent from the muddy water treatment facility through the muddy pipe 33 fills the cutter chamber 32 with pressure and stabilizes the face. On the other hand, the earth and sand cut by the cutter 31 is discharged together with the muddy water from the inside of the cutter chamber 32, and is conveyed to a muddy water treatment facility through a drainage pipe 35. In the muddy water treatment equipment, the specific gravity, viscosity, etc. of the muddy water are appropriately adjusted in the adjusting tank, and the muddy water thus adjusted is sent to the cutter chamber 32 again.

In the above-mentioned muddy water pressurizing shield method, the detecting device A is provided in the middle of the mud drain pipe 35, and the suction port 2 and the discharge port 3 of the supply pipe line 1 are opened to the mud pipe 35.

As described above, when the detecting device of the present invention is applied to the muddy pressurized shield method, the gas generated at the face is taken into the cutter chamber 32 together with the cutting soil and becomes muddy water and is discharged from the mud pipe 35. Be muddy. The mud discharged from the sludge pipe 35 in this way enters the supply pipe 1 of the detection device A provided in the middle of the sludge pipe 35 with the gas, and reaches the deaeration chamber 6 of the detection device A. I do. Thus, the gas components contained in the muddy water are degassed in the degassing chamber 6, and the gas is carried into the harmful gas detector 10 through the exhaust pipe 7. And if there is a harmful gas such as methane gas in the incoming gas,
Danger is detected by the detector 10, and the harmful gas is further conveyed to the processing device 11 and processed as appropriate.

Next, as shown in FIG. 4, a horizontal boring 40 is drilled in advance in the direction to be cut in the face of the shield method, and the detecting device A of the present invention is installed near the tip of the horizontal boring 40. The method will be described.

A boring pipe (not shown) is inserted through a through hole 43 provided in a bulk head 42 of a shield machine 41 to perform boring.
Perforate. The detecting device A of the present invention is installed near the tip of the horizontal boring 40, and the cut soil collected near the tip of the horizontal boring 40 is turned into muddy water and guided to the degassing chamber 6 of the detecting device A to detect the presence or absence of harmful gas. Is detected. The distal end of the cable 45 passing through the horizontal boring 40 is connected to the detecting device A, and the controller 4 is connected to the proximal end of the cable 45.
6, alarm 47, bowling distance meter 48, and display 5
0 are connected respectively. The detection device A is appropriately controlled by the controller 46 to detect the presence or absence of harmful gas in the vicinity of the tip of the horizontal boring 40. If a harmful gas is generated, an alarm 47 issues an alarm. The boring distance meter 48 is composed of, for example, an optical position detecting device having a mirror mounted at the tip of the boring pipe, a wire type position detecting device, a position detecting device of a type that accumulates the extruded amount of the boring pipe, and the like. You. Horizontal boring 40 by boring distance meter 48
Is measured, and the distance and the detection device A at the distance are measured.
The presence / absence of the harmful gas detected by the above is also displayed on the monitor 50 on the monitor.

The monitor surface 51 of the display 50 is, for example, as shown in FIG.
The configuration is as shown in FIG. When the distance of the horizontal boring 40 measured by the boring distance meter 48 is, for example, 6 m,
The lamps 52,... Are turned on one by one as the depth becomes 12m, 18m, 24m,.
The distance of 0 is displayed stepwise. In addition, the type of gas is illustrated in the example section 53, and the type of gas detected near the tip when the horizontal boring 40 reaches each depth is displayed on the gas type display section 55 in accordance with the example. Then, at each depth of the horizontal boring 40, the detection result of the concentration of each gas is displayed on the display unit 56, respectively. In the illustrated example, when the depth of the horizontal boring 40 is 6 m, it is detected that all of the gas types 1, 2 and 3 have high concentration, and when the depth of the horizontal boring 40 is 12 m, the gas types 1 and 2 are detected. 2 is detected as having a high concentration. When the depth of the horizontal boring 40 is 18 m, the gas type 1 is detected as having a high concentration. Further, when the depth of the horizontal boring 40 is 24 m, the gas type 3 is detected. This indicates that high concentration was detected. In addition, it is convenient to provide, above the monitor surface 51, an alarm display unit 57 for notifying that a predetermined time has elapsed, and operation buttons 58 for operating recording, reproduction display, printing, and the like of detection data. .

According to this method, it is possible to detect in advance whether or not a harmful gas is present in the direction to be cut in the cutting face of the shield method, thereby preventing danger such as oxygen deficiency or explosion. It becomes possible.

[0029]

In any case, according to the present invention, harmful gas generated from the ground can be detected in real time in the mine where the shield method is constructed, and a safe and sanitary working environment can be provided. According to the present invention, the disadvantages of the conventional check boring from the ground, such as only a point check and a limited boring area, can be solved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a detection device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a detection method when the detection device is applied to an earth pressure shield method.

FIG. 3 is a diagram illustrating a detection method when the detection device is applied to a muddy water pressure shield method.

FIG. 4 is a view for explaining a method of installing a detecting device by piercing a horizontal boring on a face;

FIG. 5 is a front view of a monitor surface.

[Explanation of symbols]

 A detection device 1 supply line 6 deaeration chamber 7 exhaust line 10 harmful gas detector 11 harmful gas treatment device

Claims (6)

(57) [Claims] 1. A supply pipe for guiding cutting soil and soil in the ground where a shield method is performed in a muddy state to a deaeration chamber, and detecting gas degassed from the muddy water in the deaeration chamber for harmful gas detection. A harmful gas detector at a face of a shield method, comprising: forming an exhaust pipe for conveying to a vessel, and further comprising a harmful gas processing device downstream of a detector of the exhaust pipe. 2. The harmful gas detection device for a face of a shield method according to claim 1, wherein a pre-filter for collecting coarse particles in muddy water is provided upstream of the degassing chamber of the supply pipe. 3. The shield method according to claim 1, further comprising a pump provided in a degassing chamber in a middle of the exhaust pipe for conveying gas degassed from the muddy water to a harmful gas detector. Hazardous gas detector at face. 4. In the earth pressure shield method, a sampling pipe for circulating the earth and sand taken in the cutter chamber into muddy water is formed at the back of the bulkhead, and the muddy water circulating through the sampling pipe is supplied to the deaeration chamber. A method for detecting a harmful gas using the detection device according to any one of claims 1 to 3, wherein the detection device detects the presence or absence of a harmful gas. 5. The muddy water pressurizing shield method according to claim 1, wherein a part of the muddy water discharged by a drainage pipe is guided to said degassing chamber to detect the presence or absence of harmful gas. A harmful gas detection method using the detection device according to 1. 6. In the face of the shield method, a horizontal boring is perforated in a direction to be cut from now on, and the cutting soil near the tip of the horizontal boring is made muddy and guided to a deaeration chamber to check for the presence of harmful gas. A harmful gas detection method using the detection device according to any one of claims 1 to 3 configured to detect the harmful gas.