JP3131551B2 - Face stabilization method of muddy water 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 method for stabilizing a face in a muddy shield method, and more particularly to a method for stabilizing a face in a muddy shield method, which achieves quick response of face management and space saving of ground equipment.

[0002]

2. Description of the Related Art As is well known, in the muddy water shield method,
The earth and sand removed by the cutter of the shield machine and taken into the shield chamber are mixed with muddy water supplied through a mud pipe, and discharged to the outside through a mud drain pipe.

[0003] In such a muddy water shield method, a shield chamber between a partition wall and a face is filled with pressurized muddy water to stabilize the facet, and excavated earth and sand is taken into muddy water to be discharged as ground muddy water. The fluid is transported to a muddy water treatment facility, the sediment is classified by the muddy water treatment facility, the mud is adjusted to a predetermined property, and the muddy water is circulated again as muddy water.

As described above, when managing muddy water on the ground,
For example, as shown in FIG. 7, in the ground equipment, in the segment stock yard 1, the fresh water tank 2, the adjusting tank 3, the vibrating sieve 4, the belt conveyor 5, 6, the filter press 7, the water purifying tank 8, the PH control device 9, the PAC Storage tank 10, truck loading section 11, surplus mud tank 12, earth and sand hopper 1
3, 14, etc., mud storage tank 15, mud storage tank 16, clay storage yard 17, CMC dissolution tank 18, CMC for mud water management
A storage yard 19 and the like are provided.

Further, as described above, in addition to the case where muddy water treatment facilities are provided on the ground to manage muddy water on the ground, there are also cases where muddy water management facilities are provided in the starting shaft and muddy water management is performed in the starting shaft. .

[0006]

The conventional muddy water shield method has the following problems.

[0007] First, when muddy water is adjusted on the ground or in a starting shaft and the mud is sent to the face as in the conventional case, after confirming the change in the stability of the face, the muddy water is adjusted according to the change in the stability of the face. The adjusted mud is sent to the shield chamber via a mud pipe.In such a state, even if the mud is sent immediately after adjusting the mud, the adjusted mud reaches the face. It takes a considerable amount of time to complete the operation, and after detecting the change in the stability of the face, the face may be loosened or collapsed before the adjusted muddy water reaches the face. There was a problem that it was difficult to respond quickly.

For example, in the case of a shield with an excavation distance of 1000 m, even if muddy water is supplied to the face immediately after adjusting the muddy water in accordance with the change in the stability of the face, the flow rate of the muddy water is generally 2 m / sec. It takes about 8 minutes for the adjusted muddy water to reach the face, and the response to the change of the face is delayed for 8 minutes or more after detecting the change in the stability of the face.

Further, as in the conventional case, when muddy water is managed on the ground or in a starting shaft, the mud making storage tank 15, the mud making tank 16,
Muddy water management facilities such as a clay storage yard 17, a CMC dissolution tank 18, a CMC storage yard 19, and the like are required. For these muddy water management facilities, a vast area is required as ground equipment, or muddy water management in a starting shaft. When the equipment is provided, a large shaft is required, and there is a problem that the required area of the ground equipment increases accordingly.

Particularly in urban areas, it is becoming difficult to secure a vast land area for ground facilities, and thus it is difficult to secure sufficient land for ground facilities. If not, there is a problem that it is becoming difficult to excavate the tunnel.

For example, when a new water and sewage tunnel is to be excavated in place of an aging water and sewage system, when excavating an old tunnel, there are parks and vacant lots.
The ground equipment was installed and constructed there, but now the environment changes and parks and vacant lots may not be available as work space, so it is not possible to secure a large land area for ground equipment Such a case occurs.

Further, in the conventional muddy water shield construction method, an adjusting tank 3 for storing muddy water having a sludge amount of about 10 minutes is required as a countermeasure against lost mud and the like.
Moreover, since the muddy water is adjusted in the adjusting tank 3, all the stock is covered by the adjusting tank 3, so that the adjusting tank 3 is large and the land area for the ground equipment is correspondingly large. was there.

The present invention has been made in view of the above-mentioned conventional problems, and its object is to enable quick response to face management, and to reduce the amount of muddy water stock for muddy water management equipment and sludge countermeasures. Accordingly, it is an object of the present invention to provide a face stabilizing method of a muddy water shield method capable of reducing a land area for ground equipment and saving an area.

[0014]

According to a first aspect of the present invention, there is provided a method for stabilizing a face in a muddy shield method in which muddy water is supplied into a shield chamber of a shield machine and the face is stabilized by muddy water pressure. A thickener tank and a viscometer are arranged in the middle of the mud pipe in the tunnel behind the shield machine, and the viscosity in the mud pipe is detected by the viscometer based on the face data obtained by detecting the face condition. In addition, the thickener is supplied from the thickener tank into the mud pipe and supplied to the face.

A second invention is characterized in that the thickener tank and the viscometer are arranged immediately after the shield machine.

The third invention is characterized in that the thickener is mixed with the muddy water by a line mixer provided in the middle of the mud feeding pipe.

According to a fourth aspect of the present invention, in addition to the thickener tank,
It is characterized in that a plugging material tank is provided in the middle of the mud pipe to supply the plugging material into the pipe.

[0018]

According to the first aspect of the present invention, the viscosity in the mud pipe is measured by a viscometer arranged in the middle of the mud pipe behind the shield machine based on the face data obtained by detecting the face condition. While detecting, the muddy water is adjusted in the tunnel behind the shield machine by supplying the thickener from the thickener tank arranged in the tunnel behind the shield machine and supplying it to the face. The distance from the muddy water adjusting equipment to the face can be shortened, and as a result, the time from detecting the change in the stability of the face by the face data to sending the adjusted muddy water to the face can be reduced. It can be greatly shortened, and quick response to face management is possible.

Further, since the muddy water is adjusted by directly supplying the thickening agent into the mud feeding pipe, the muddy water adjustment time can be shortened, and the response time can be shortened accordingly.

Therefore, it is possible to reliably prevent the face from being loosened or collapsed due to a delay in response between the detection of the change in the face stability and the supply of the adjusted muddy water to the face as in the related art.

Further, in order to adjust the muddy water by supplying the thickener directly from the thickener tank disposed in the tunnel into the mud feed pipe, a mud storage tank, a mud tank, and the like are provided on the ground or in the starting shaft.
There is no need to install muddy water management facilities such as clay storage yards, CMC dissolution tanks, and CMC storage yards. As a result, even if it is difficult to secure a vast land area for ground facilities, such as in an urban area, construction can be performed.

According to the second aspect of the present invention, by disposing the thickener tank and the viscometer immediately after the shield excavator, it is possible to further reduce the feeding distance of the adjusted muddy water to the face. A more rapid response can be achieved by face management.

According to the third invention, the thickener is mixed with the muddy water by a line mixer disposed in the middle of the mud feed pipe, so that the thickener is mixed with the muddy water using the energy of the mud flow. Can be stirred and mixed, and a mechanism for stirring and mixing can be simplified and downsized.

According to the fourth invention, in addition to the thickener tank, a plugging material tank is provided in the middle of the mud feeding pipe, and the plugging material is supplied into the mud feeding pipe so that the plugging material is supplied into the tunnel. As a countermeasure against lost mud, it is no longer necessary to prepare a large amount of muddy water as a countermeasure against lost sludge, and the size of the adjusted tank can be reduced, thereby reducing the land area for ground equipment. As well as quick response to lost mud.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 to 6 are views showing a method for stabilizing a face in a muddy water shield method according to an embodiment of the present invention.

In this muddy water shield method, a ground facility 30 is provided on the ground, a starting shaft 32 is excavated from the ground facility 30 to a predetermined depth, and a ground excavator 34 uses a shield excavator 34 from a bottom position of the starting shaft 32. The tunnel 36 is constructed while excavating the inside in the lateral direction and assembling the segments.

The shield machine 34 is of a mud type, and supplies mud from the ground via a mud pipe 44 into a shield chamber 42 between a shield machine body 38 and a cutter disk 40. 42 is filled with pressurized muddy water to stabilize the face 46, the excavated earth and sand is taken into muddy water, and fluid is transported to the ground through a mud drainage pipe 48 as muddy water, and the sediment is classified on the ground. ,
The mud is adjusted to a predetermined normal state, and is again circulated and used as muddy water.

In this embodiment, in order to stabilize the face, a face stabilizing method for managing muddy water in the tunnel 36 is employed.

In this face stabilizing method, a thickening material tank 50 and a plugging material tank 52 are provided in the tunnel 36 at a position behind the shield machine 34 in the tunnel 36. By controlling the viscosity of muddy water on the way, stable management of the face 46 can be performed.

Specifically, the thickener tank 50 and the plugging material tank 52 are mounted on a rear bogie (not shown) behind the shield machine 34 in the tunnel 36 connected to the shield machine 34. A line mixer 54 is interposed in the mud feed pipe 44 at a position corresponding to the rear bogie on which the thickener tank 50 and the plugging material tank 52 are placed, and the line mixer 54 is provided with snake pumps 56 and 5.
8, the thickener tank 50 and the plugging material tank 52 are connected.

A viscometer 60 is provided in the mud pipe 44 between the line mixer 54 and the shield machine 34, and the viscometer 60 is connected to the pumps for the snake pumps 56, 58 via an arithmetic unit 62. It is in a state of being connected to the control devices 72 and 74.

In addition, flow meters 64, 66 and density meters 68, 70 are provided in the mud pipe 44 and the mud pipe 48 between the line mixer 54 and the shield machine 34, and these flow meters 64, 66 are provided. And the density meters 68 and 70 are provided by the arithmetic unit 6
2 is connected.

The viscometer 60 detects the viscosity of the muddy water supplied from the thickener tank 50 and the filling material 52 into the mud pipe 44 and mixed with the thickening material and the filling material by the line mixer 54. The viscosity data is sent to the arithmetic unit 62. For example, although not shown, Japanese Unexamined Patent Application Publication No.
As shown in JP-A-271495, a pressure measuring device that measures the pressure of the muddy water flowing in the duct of the mud pipe 44 at at least two points, and calculates the viscosity of the muddy water based on the differential pressure of the measured muddy water pressure. By adopting a device provided with a viscosity calculating means, the viscosity of muddy water supplied as a stabilizing liquid can be measured automatically and in real time. In particular, in recent shield construction methods, central control of shield excavators is performed by computer, and the viscosity of the supplied muddy water can be accurately grasped in real time as described above. It is a target.

Further, a new viscometer as shown in FIGS. 4 to 6 can be employed.

This viscometer is disclosed in Japanese Patent Application Laid-Open No. 3-27149.
After the filing of the invention disclosed in Japanese Patent Publication No. 5, the research and development of the viscosity of the mud was further advanced. In the method of obtaining the viscosity from the pressure difference of the mud, a more accurate viscosity was obtained by considering the flow velocity V of the mud. It was thought that it was found that measurement was possible.

That is, when the flow rate of the muddy water flowing in the pipeline does not change so much, the viscosity of the muddy water can be accurately measured only by the differential pressure of the muddy water. However, in recent years, rapid construction has been performed in order to increase the work efficiency of the construction, and when such a construction method is adopted, the flow velocity of the muddy water flowing in the pipeline often changes remarkably. For example, when rapid construction is adopted at a mud pressurized shield site, the excavation speed varies greatly depending on the type of ground to be excavated, and the flow velocity of the mud flowing through the pipeline also varies greatly according to this. . In such a case, the viscosity of the mud cannot be accurately measured unless the change in the flow velocity V of the mud is also taken into consideration.

For this reason, in this embodiment, the relationship between the differential pressure Δh of the mud flowing through the pipeline and the flow velocity V is measured in advance using the viscosity as a parameter, and the differential pressure ΔH of the mud flowing through the pipeline is measured. , Data representing the correlation between flow rate V and viscosity.

Thereafter, the differential pressure Δh and the flow velocity V of the mud flowing in the pipeline are actually measured, and the measured data and the correlation data obtained in advance are compared with each other, regardless of the fluctuation of the flow velocity of the mud. , The viscosity can be automatically measured accurately.

Therefore, the muddy water characteristic measuring system of the embodiment includes a differential pressure measuring unit 140, a flow velocity measuring unit 150, a memory 174, and a viscosity calculating unit 176, as shown in FIG.

The differential pressure measuring section 140 includes at least two pressure measuring devices 142 a and 142 b and a differential pressure detecting section 144.
It is comprised including. Each of the pressure measuring units 142a, 142
42b is a predetermined distance l (in the embodiment, l)
= 10m), and measures the pressure Pa, Pb of the muddy water at each installation position and outputs the measured pressure to the differential pressure detection unit 144.

The differential pressure detecting section 144 obtains the differential pressure Δh of each of the measured pressures Pa and Pb input as described above from the following equation, and outputs it to the viscosity calculating section 176. Δh = Pa−Pb The flow rate measuring unit 150 is provided with the pressure measuring devices 142a, 142
It is located near the installation of 42b and is attached to the pipeline, measures the flow velocity V of the muddy water flowing in the pipeline and outputs it to the viscosity calculation unit 176. The flow velocity measuring unit 150 may have various configurations as needed.
A configuration similar to that of the invention according to No. 1495, which measures the flow velocity using ultrasonic waves, is used.

The memory 174 stores correlation data. That is, the differential pressure of the muddy water flowing in the pipeline using the differential pressure measurement unit 140 and the flow velocity measurement unit 150
The data representing the correlation between h, the flow velocity V and the viscosity is actually measured in advance, and the correlation data obtained by the actual measurement is stored.

Hereinafter, the details of the correlation data of the differential pressure Δh of the muddy water, the flow velocity V and the viscosity stored in the memory 174 in advance will be described.

In FIG. 6, the system of the embodiment was mounted on a mud pipe at the pressurized mud shield site, and the flow velocity V and the differential pressure Δh of the mud flowing through the pipe were measured using the funnel viscosity FV as parameters. Values are shown. Here, the funnel viscosity is FV = 19.71 sec to FV = 31.88.
For 5 types of muddy water during sec, change the flow velocity V,
The differential pressure Δh at that time is actually measured. In the figure, T is a temperature.

As shown in the figure, FV = 19.71 sec.
Of the mud is approximated by a second order polynomial, FV = 21,
The characteristics of the mud from 98 sec to FV = 31.88 sec are as follows:
It is approximated by a linear expression. The substance of mud with FV = 19.71 is water, and its characteristics are completely different from those of mud with FV = 21.98 or more (solid particles suspended in liquid).
FV = 21.98-31.88 sec.
This is clearly the flow of Hagen Poiseuille. In such a Hagen Poiseuille flow, the pressure loss Δh
Is generated by muddy water viscosity. FV = 19.
It is considered that the pressure loss Δh of the flow of 71 sec is almost due to inertial force.

As is well known, the flow in the mud transport pipe is turbulent. Critical Reynolds number Re changing from laminar to turbulent
In a slurry, Re = 1100-1200. Therefore, using the well-known Darcy-Wisebach equation and the Niklaze equation, the flow velocity when the slurry changes from laminar flow to turbulent flow is obtained for each funnel viscosity slurry as shown in FIG. , And critical Re. The flow in the pipe is considered to be laminar on the left side of this straight line, that is, on the side with the lower flow velocity, and turbulent on the right side with the higher flow velocity.

Further, in the case of a fluid having an FV of 21.98 sec or more, even in a turbulent flow region, even if the flow velocity V is increased, a good approximation represented by a linear (linear) approximation formula is obtained until the flow velocity reaches a certain velocity (critical flow velocity). Relationship is maintained. The higher the viscosity is, the larger the critical flow velocity is. Therefore, for the slurry having each funnel viscosity FV, the muddy water has a flow velocity range not less than the flow velocity corresponding to the critical Reynolds number and not more than the flow velocity (critical flow velocity) at the boundary where the approximate expression changes from the primary expression to the secondary expression. The flow velocity V and the differential pressure Δh are measured.

FIG. 7 shows the relationship between the flow velocity V of the muddy water and the pressure difference Δh for each muddy water of each funnel viscosity within the flow velocity range between the flow velocity corresponding to the critical Reynolds number and the critical flow velocity. FIG. 4 is a characteristic diagram using the measurement data, where the value of Δh / V is plotted on the horizontal axis and the funnel viscosity FV is plotted on the vertical axis. As shown in the figure, the ratio Δh / V between the differential pressure Δh of the muddy water and the flow velocity V
Has a linear correlation with the funnel viscosity FV. In the figure, the broken line indicates a range where the reliability is 95%.
In this embodiment, the approximate expression data of FIG. 7 obtained by actual measurement in this way is stored in the memory 174 in advance.

The viscosity calculating unit 176 calculates Δh / d based on the differential pressure Δh of the muddy water input from the differential pressure measuring unit 140 and the flow velocity measuring unit 150 in real time and the flow velocity V.
The value of V is calculated and the funnel viscosity FV corresponding to this value is calculated.
Is read from the data shown in FIG. The funnel viscosity FV obtained in this way is output as viscosity data of muddy water.

By doing so, the system of this embodiment is not affected by fluctuations in the flow rate of muddy water,
The viscosity can be accurately measured as a funnel viscosity.

The arithmetic unit 62 controls the pump control units 72 and 74 based on the face data obtained by detecting the condition of the face 46. The face data includes face water pressure by a water pressure gauge,
It consists of cutter torque by a torque detector, cutter slit opening, earth tank discrimination data by an underground radar, etc., and the face data and the viscosity data from the viscometer 60, the flow rates by the flow meters 64 and 66 and the density meters 68 and 70. And the density are calculated to calculate the excavated dry sand amount, excavation deviation flow rate, thickener addition amount and plugging material addition amount, and control the pump controllers 72 and 74 to control the thickener tank 50 and the plugging material tank. The feed amount of the thickener and the plugging material from 52 is controlled, and the viscosity of the mixed muddy water that has passed through the line mixer 54 is calculated by the viscometer 60 and fed back to the arithmetic unit 62. I have.

As an underground radar for detecting earth tank discrimination data, for example, although not shown, it is disposed at a predetermined interval on a cutter face of a shield machine and transmits radio waves toward the front of the shield machine. A transmitting antenna and a receiving antenna for receiving, a radio wave is transmitted forward from the transmitting antenna, a surface propagation wave propagating near the surface of the face is received by the reception antenna, and the propagation time of the surface propagation wave and the transmission antenna and By adopting a method that determines the difference in soil quality in front of the face based on the distance between the receiving antennas, it is possible to determine the difference in soil texture facing the face using surface propagation waves, Is calculated, the distance to the foreign matter that generates the reflected wave can be accurately obtained.

The arithmetic unit 62 also controls the face water pressure based on the amount of excavated dry sand and the excavation deviation flow rate.

As described above, the muddy water is adjusted in the middle of the mud feed pipe 44 at the position of the rear bogie of the shield machine 34, and the muddy water is fed to the face 46 as it is, thereby greatly shortening the muddy feeding distance of the adjusted muddy water. And quick response to face management becomes possible.

For example, if the position of the rear bogie where the thickener tank 50, the filling material tank 52, and the line mixer 54 are installed is 30 m from the face, the general flow rate of the mud is 2.
In the case of m / sec, it is possible to send the adjusted muddy water to the face in about 15 seconds.

Further, by adjusting the muddy water with the bogie behind the shield machine 34, as compared with the case where muddy water is managed on the ground or at the starting shaft, as shown in FIG. Fresh water tank 2, regulating tank 3, vibrating sieve 4, belt conveyor 5, 6, filter press 7, water purification tank 8, PH control device 9, PAC storage tank 10, truck carry-in section 11, excess mud water tank 12, earth and sand hopper 13, 14 is enough, and the facilities such as a mud storage tank, a mud storage tank, a clay storage yard, a CMC dissolution tank, and a CMC storage yard required for muddy water management are not required, and the installation area of the ground equipment is reduced by that much, thereby saving. It is possible to increase the area.

In the past, an adjustment tank for storing the muddy water with a mud feed amount of 10 minutes was normally required for countermeasures against lost mud and the like, but the viscosity management of the muddy water was carried out by the rear bogie as described above. By doing so, it is not necessary to stock the adjusted muddy water. Therefore, the combined amount of the fresh water tank 2, the surplus muddy water tank 12, and the adjusting tank 3 may be considered as the stock amount, and the land area can be saved by reducing the muddy water tank. The area can be increased.

For example, in the case of a muddy shield with an excavation outer shape of 3280 mm, when the gravel: silt clay is 95: 5, the amount of water can be reduced from a 50 m ³ adjusting tank to a 20 m ³ adjusting tank. From the ground equipment perspective, 810
m ² can be reduced to 450 m ² , and the area can be reduced by about 55%.

Next, a method for stabilizing the face in the shield machine 34 will be described.

First, face data, such as face water pressure, cutter torque, cutter slit opening, earth tank discrimination data, etc., are sent from various detection devices in the shield chamber 42 to the arithmetic unit 62.
Sent to.

The arithmetic unit 62 monitors the stability of the face based on the various face data, and calculates the viscosity data and the viscosity data detected by the viscometer 60, the flow meter 64 and the density meter 68 provided in the mud pipe 44. The properties of the muddy water in the mud feed pipe 44 are determined from data such as the flow rate and the density. Further, the degree of collapse of the face 46 is determined based on data from the flow meter 66 and the viscometer 70 provided in the exhaust pipe 48. From these data, the arithmetic unit 62 calculates the amount of excavated dry sand and the excavated deviation flow rate. When loosening of the face is expected, the viscosity of the muddy water and the amount of thickener necessary to obtain the value are calculated. Assuming the amount of plugging material necessary for preventing sludge loss, the respective addition amount control signals are transmitted to the pump controllers 72 and 74, and a signal is transmitted to the ground equipment to adjust the face water pressure. The appropriate viscosity is, for example, at least 2 poise or more, desirably 4 poise or more for a permeable ground.

The pump control devices 72 and 74 are
In response to the control signal of 2, the snake pumps 56 and 58 are controlled to supply the required amount of the thickener and the plugging material from the thickener tank 50 and the plugging material tank 52 to the center of the mud pipe 44. .

The thickener and the plugging material supplied into the mud pipe 44 are used by the line mixer 54 provided in the middle of the mud pipe 44 by utilizing the energy of the mud flow in the mud pipe 44. Then, it is mixed with the muddy water by stirring.

The muddy water that has been stirred and mixed by the line mixer 54 and adjusted is supplied to a viscometer 60
After passing through the flow meter 64 and the density meter 68, each of these meters transmits each data to the arithmetic unit 62, judges the adjustment status by the arithmetic unit 62, and supplies the adjusted muddy water into the shield chamber while performing the feedback control. As a result, the face 46 is stabilized.

As described above, the muddy water is managed on the rear bogie behind the shield machine 34, and the adjusted muddy water is supplied from the rear bogie position to the face 46, whereby a quick response to a change in the stability of the face is possible. As in the conventional case, it is possible to prevent the face from being loosened, collapsed, or having lost mud before the supply of the adjusted muddy water due to a delay in response.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

For example, in the above-described embodiment, the case where the thickener tank and the plugging material tank and the like are arranged on the rear bogie 30 m behind the shield machine, but the present invention is not limited to this example. By arranging at a position closer to the shield excavator side, it is possible to respond more quickly to a change in the stability of the face.

Further, the viscometer and the underground radar are not limited to those described in the above embodiments, and various types can be employed.

[0070]

As described above, according to the first aspect of the present invention, based on the face data obtained by detecting the state of the face, the viscometer disposed in the middle of the mud pipe behind the shield machine extrudes the mud. By detecting the viscosity in the pipe and supplying the thickener into the mud pipe from the thickener tank arranged in the tunnel behind the shield excavator and supplying it to the face, the tunnel inside the tunnel behind the shield excavator Can adjust the muddy water, and reduce the distance from the muddy water adjusting equipment to the face.
As a result, the time from detecting the change in the stability of the face based on the face data to sending the adjusted muddy water to the face can be greatly reduced, and quick management of the face can be performed. In addition, since the muddy water is also adjusted by directly supplying the thickener into the mud pipe, the muddy water adjustment time can be shortened, and the response time can be shortened accordingly. .

Accordingly, the effect that the loosening or collapse of the face due to a delay in response can be reliably prevented before the adjustment muddy water is supplied to the face after detecting the change in the face stability as in the related art. is there.

Further, since the muddy water is adjusted by supplying the thickener directly from the thickener tank disposed in the tunnel into the mud feed pipe, a mud storage tank, a mud tank,
There is no need to install muddy water management facilities such as clay storage yards, CMC dissolution tanks, CMC storage yards, etc., and the area required for installation of this muddy water management equipment becomes unnecessary, and the area required for ground equipment is greatly reduced, thus saving area. As a result, even if it is difficult to secure a vast land area for ground facilities, such as in an urban area, there is an effect that construction can be performed.

According to the second aspect, the thickener tank and the viscous system are disposed immediately after the shield machine,
There is an effect that the mud feeding distance of the adjusted muddy water to the face can be further shortened, and a more rapid response can be made to the face management.

According to the third aspect of the present invention, the thickener is mixed with the muddy water by the line mixer disposed in the middle of the mud feed pipe, so that the thickener is mixed with the muddy water using the energy of the mud flow. Can be agitated and mixed, and there is an effect that a mechanism for agitating and mixing can be simplified and downsized.

According to the fourth invention, in addition to the thickener tank, a plugging material tank is provided in the middle of the mud pipe, and the plugging material is supplied into the mud pipe, so that the material is evacuated in the tunnel. As a countermeasure against mud, it is not necessary to use a regulating tank for a large amount of muddy water as a countermeasure against lost mud, as in the past, and the regulating tank can be made smaller and the land area for ground equipment can be reduced accordingly. At the same time, there is an effect that it is possible to quickly respond to lost mud.

[0076]

[Brief description of the drawings]

FIG. 1 is an overall schematic view showing a face stabilizing method of a muddy water shield method according to an embodiment of the present invention.

FIG. 2 is an enlarged schematic view showing a main part in a face stabilization method of the muddy water shield method shown in FIG.

FIG. 3 is a plan view showing an arrangement state of ground equipment in the present embodiment in comparison with FIG.

FIG. 4 is a block diagram illustrating an example of a viscometer.

FIG. 5 is a characteristic diagram when the flow rate and the differential pressure of the muddy water are measured using the funnel viscosity as a parameter.

FIG. 6 is a characteristic diagram of muddy water with the ratio of differential pressure and flow velocity of the muddy water taken along the horizontal axis and the funnel viscosity taken along the vertical axis.

FIG. 7 is a plan view showing a state of ground equipment in a conventional muddy water shield method.

[Explanation of symbols]

 Reference Signs List 34 shield excavator 42 shield chamber 44 mud pipe 46 face 50 thickener tank 52 filling material tank 54 line mixer 60 viscometer 62 arithmetic unit 64 flow meter 68 density meter

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Jun Yamashita 1-22-8 Nishi-Ikebukuro, Toshima-ku, Tokyo Inside the Sewerage New Technology Promotion Organization (72) Inventor Yoshio Iwai 1-chome Kyobashi, Chuo-ku, Tokyo No.7-1 Toda Construction Co., Ltd. (72) Inventor Sadao Noguchi 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd. (72) Isao Saito 1-7-1 Kyobashi, Chuo-ku, Tokyo Inside Toda Construction Co., Ltd. (72) Inventor Yasutomo Katori 1-7-1, Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd. (72) Inventor Iku Iku 1-1-1, Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd. (56) References JP-A-4-209294 (JP, A) JP-A-4-60096 (JP, A) JP-A-61-28699 (JP, A) JP-A-4-146396 (JP, A) Special JP-A-62-194317 (JP, A) JP-A-51-140335 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E21D 9/06 301

Claims (4)

(57) [Claims] [Claim 1] arranged the thickener tank and viscosity meter in the middle of Okudoro tube in shea Rudo excavator behind in the tunnel, based on the working face data detected the situation of the working face, Okudoro tube by viscometer Mud seal that supplies the thickener from the thickener tank into the mud pipe and supplies it to the face while detecting the viscosity of the water
A face stabilization method according to claim 1, wherein the viscometer measures pressure at at least two points in the mud pipe.
Differential pressure measuring means for measuring as a force difference, and flow velocity measuring means for measuring the flow velocity of muddy water in the mud pipe
And muddy water flowing in the mud pipe determined in advance by measurement
Storage means for storing the relationship between the differential pressure, the flow rate and the viscosity, the measured flow rate and the differential pressure, and the storage data of the storage means;
Calculating means for determining the viscosity of the muddy water, wherein the storage means stores a ratio Δh /
V and the related data stored in the storage means.
A face stabilizing method for a muddy shield method, which is formed to determine the viscosity of muddy water . 2. The face stabilizing method according to claim 1, wherein the thickener tank and the viscometer are disposed immediately after the shield machine. 3. The face stabilizing method according to claim 1, wherein the thickener is mixed with the muddy water by a line mixer provided in the middle of the mud pipe. 4. The muddy water type according to claim 1, wherein a plugging material tank is provided in the middle of the mud feeding pipe in addition to the thickener tank, and the plugging material is supplied into the mud feeding pipe. Face stabilization method of shield method.