JP5425856B2 - Muddy water type shield machine - Google Patents

Description

  The present invention relates to a muddy water shield machine, and more particularly to a muddy water shield machine that performs tunnel tunneling while stabilizing a face surface by the pressure of muddy water filled in a cutter chamber.

  The muddy water shield machine forms a cutter chamber partitioned by a partition wall behind the cutter head that is provided at the tip of the machine body and excavates the face, and fills the cutter chamber with muddy water. This is a shield excavator that excavates the tunnel while stabilizing the face with the pressure of the muddy water (muddy water pressure). The muddy water filled in the cutter chamber is circulated between the muddy water tank and muddy water tank, and excavated soil Is transported together with muddy water to a muddy water tank or muddy water tank, so that the tunnel can be dug while discharging excavated earth and sand excavated by the cutter head from the cutter chamber.

  In addition, as an improvement of the muddy water shield machine, an air chamber is formed behind the cutter chamber, and the cutter chamber and the air chamber are communicated with each other at the lower part thereof, so that the muddy water layer in the air chamber is located above the muddy water layer. A mud shield shield machine equipped with an air chamber has been developed in which a tunnel is dug in a state where an air layer is formed (see, for example, Patent Document 1).

  In the muddy water type shield machine equipped with such an air chamber, for example, the height of the muddy water level, which is the boundary between the muddy water layer and the air layer in the air chamber, the air pressure of the air layer, the cutter chamber, Pressure fluctuations due to changes in water pressure from the ground surface on the face face are controlled by controlling the mud flow and mud discharge to the air chamber, and the air layer in the air chamber. The tunnel can be dug while being relaxed by the compressive and expansibility of air.

JP 2003-120176 A

  On the other hand, the soil quality of the natural ground excavated by the muddy water shield excavator changes with the tunnel excavation. In particular, in the case of a tunnel with a large section, the soil texture of the natural ground is not homogeneous in the cross-sectional direction. In many cases, for example, when a sand layer, a gravel layer, or a bedrock layer with a low uniformity coefficient is encountered, or when these layers are included in the face, there is a loss of water due to the eruption or release of muddy water. May cause trouble. When water loss or the like occurs, the pressure in the cutter chamber or the air chamber is also rapidly lowered by the pressurized muddy water in the cutter chamber being removed from the face to the ground. Further, for example, when a mud pipe for draining muddy water from the cutter chamber is blocked or cavitation occurs, the pressure in the cutter chamber or the air chamber will rise rapidly.

  Here, if there is water loss on the face, clogging of the sludge pipe, etc., if these can be detected and the pressure in the cutter chamber or air chamber can be recovered quickly, the face will be stabilized and digging will continue. It will be possible to do it. If the pressure in the cutter chamber or air chamber suddenly drops or rises, the water level of the muddy water layer in the air chamber will also fluctuate up and down. It is important to accurately detect and manage the water level on the surface in order to quickly recover the pressure in the cutter chamber and the air chamber and stabilize the face.

  For this reason, for example, in the muddy water type shield machine equipped with the air chamber of Patent Document 1, the air layer in the air chamber and the muddy water layer are communicated by projecting from the main body side partition wall that partitions the air chamber to the inside of the tunnel. A tubular sensor mounting body is provided, and in this sensor mounting body, for example, a reflecting plate disposed on the water surface in the sensor mounting body, and the water level in the sensor mounting body is measured by light rays and sound waves emitted toward the reflecting plate. The water level of the muddy water layer can be measured using a detecting laser or ultrasonic sensor. In addition, this sensor mounting body is provided so as to project inside the tunnel mine, so that it can be replaced or inspected by work from inside the tunnel mine without workers entering the air chamber. Be able to.

  However, in the muddy water shield machine described in Patent Document 1, the muddy water level inside the tubular sensor mounting body can be accurately measured, while the muddy water forming the muddy water layer has a high specific gravity. In order to do so, bentonite components and the like are included, and the viscosity is high, so that the water level of the muddy water layer in the air chamber decreases or rises as the pressure in the air chamber decreases or rises. A considerable amount of time is required until the water level of the muddy water layer falls or rises in the tubular sensor mounting body. In particular, when the pressure in the cutter chamber or air chamber suddenly drops or rises, there is a considerable time delay until it is detected inside the sensor mounting body, and the inside of the cutter chamber or air chamber It is considered difficult to quickly recover the pressure of Therefore, for example, when the pressure in the cutter chamber or air chamber suddenly drops or rises, the drop or rise in the liquid level of the muddy water layer in the air chamber due to the drop or rise in these pressures is delayed in time. New technology development that enables immediate detection without causing trouble, and allows the level gauge to be replaced or serviced without the operator entering the air chamber. It is desired.

  In the present invention, for example, when the pressure in the cutter chamber or the air chamber suddenly decreases or increases, the decrease or increase in the water level of the muddy water layer in the air chamber accompanying the decrease or increase in these pressures, An air chamber that can be detected immediately using a liquid level gauge without causing a time lag, and can be replaced or serviced without an operator entering the air chamber. An object is to provide a muddy water type shield machine.

  The present invention is provided by a cutter head provided at the tip of the excavator main body for excavating the face, and a cutter-side partition disposed behind the cutter head, and the cutter-side partition and the cutter head A cutter chamber formed between the main body side partition wall and the cutter side partition wall, and is partitioned by a main body side partition wall disposed behind the cutter chamber. In the muddy water type shield excavator that excavates the tunnel while stabilizing the face by the pressure of the muddy water filled in the cutter chamber, the air chamber and the cutter chamber are provided below the cutter side partition wall. By communicating through the communication port, a muddy water layer is formed at the lower part of the air chamber and an air layer is formed at the upper part. It is possible to dig a tunnel while mitigating the pressure fluctuation on the ground surface on the face surface by the compressive expansibility of the air in the air layer in the air chamber. Is projecting from the main body side partition to the cutter side partition side, and a liquid level gauge installation chamber is provided with a measurement opening formed in the bottom surface portion arranged in a portion directly above the liquid level of the muddy water layer, In the liquid level gauge installation chamber, a valve mechanism that opens and closes a hollow measurement path between the measurement opening and the sealing opening is interposed to detect a reflected wave from the liquid level of the muddy water layer and to detect the muddy water layer. The liquid level gauge that measures the water level provides the muddy water type shield machine that is detachably installed, thereby achieving the above object.

  In the muddy water type shield machine according to the present invention, the valve mechanism is integrally joined to the opening peripheral edge of the measurement opening, and has a lower flange member having a through opening at a central portion, and above the lower flange member. A valve member joined as a unit, and an upper flange member that is detachably joined to the upper part of the valve member and that has a through-opening at a central portion thereof. It is preferable that the surface meter is attached integrally.

  In the muddy water shield machine according to the present invention, the valve member is preferably a ball valve.

  Furthermore, in the muddy water type shield machine according to the present invention, the liquid level gauge is preferably an ultrasonic liquid level gauge.

  Furthermore, in the muddy water type shield machine according to the present invention, it is preferable that the liquid level gauge installation chambers in which the liquid level gauge is installed are respectively provided on both sides of the central portion of the air chamber.

  According to the muddy water type shield machine equipped with the air chamber of the present invention, for example, when the pressure in the cutter chamber or the air chamber suddenly decreases or increases, the muddy water in the air chamber accompanying the decrease or increase in these pressures. A drop or rise in the water level in the bed can be detected immediately using a liquid level gauge without causing a time delay, and the liquid level gauge can be replaced without entering the air chamber. Maintenance and inspection.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic longitudinal sectional view illustrating a configuration of a muddy water shield machine according to a preferred embodiment of the present invention. It is sectional drawing along AA of FIG. FIG. 5A is a perspective view of a liquid level gauge installation room where a liquid level gauge is installed, and FIG. 5B is a perspective view of the liquid level gauge installation room seen through, and FIG. . It is a perspective view explaining the structure of a lower flange member. It is a perspective view explaining the structure of an upper flange member.

  A muddy water type shield machine 10 according to a preferred embodiment of the present invention shown in FIGS. 1 and 2 is a road or road having a diameter of about 6 to 20 m, for example, on the ground where ground water exists, In the construction of a tunnel for a subway, it was adopted as a shield machine for digging the tunnel while stabilizing the face surface 20 by mud pressure (muddy water pressure) without affecting the surrounding ground. Is. Further, the muddy water type shield machine 10 of the present embodiment is further provided with an air chamber 14 behind the cutter chamber 13 formed behind the cutter head 12 excavating the face 20, so that the ground on the face 20 It has a function of enabling tunnel excavation while mitigating the pressure fluctuation on the mountain side by the compressibility of the air in the air layer 15 formed in the air chamber 14. Furthermore, for example, when the pressure in the cutter chamber 13 or the air chamber 14 suddenly drops or rises due to water loss on the face 20 or clogging of the mud pipe during tunnel excavation, these pressures It has a function that enables a liquid level gauge 44 to immediately detect a drop or rise in the water level of the liquid surface 19a of the muddy water layer 19 in the air chamber 14 caused by the drop or rise. ing.

  That is, the muddy water type shield machine 10 according to the present embodiment includes a cutter head 12 provided at the tip of the machine 11 and excavating the face 20 and a cutter-side partition wall 16 disposed behind the cutter head 12. The main body side partition wall 17 and the cutter side partition wall are partitioned by a cutter chamber 13 formed between the cutter side partition wall 16 and the cutter head 12 and a main body side partition wall 17 disposed behind the cutter chamber 13. The shield chamber machine includes an air chamber 14 formed between the air chamber 14 and the tunnel chamber 20 while stabilizing the face 20 by the pressure of the muddy water 21 filled in the cutter chamber 12. The cutter chamber 13 is a communication port 1 provided at the lower part of the cutter side partition wall 16. The muddy water layer 19 is formed in the lower part of the air chamber 14, and the air layer 15 is formed in the upper part of the air chamber 14, and the pressure fluctuation on the ground surface in the face 20 is changed to the air layer in the air chamber 14. The tunnel can be dug while being relaxed by the compressibility of 15 air.

  And in the upper part of the main body side partition wall 17, the liquid level gauge installation chamber 40 projects from the main body side partition wall 17 to the cutter side partition wall side 16, and the measurement opening 41 formed in the bottom surface portion 40 a of the muddy water layer 19. As shown in FIGS. 3 (a) and 3 (b), the liquid level gauge installation chamber 40 is provided with a hollow measurement path 42 between the measurement opening 41 and disposed directly above the liquid level. A level gauge 44 for detecting the reflected wave from the liquid level 19a of the muddy water layer 19 and measuring the water level of the muddy water layer 19 is detachably attached via a valve mechanism 43 that opens and closes in a sealable manner.

  In the present embodiment, the valve mechanism 43 includes a lower flange member 45 having a through-opening 45a (see FIG. 4) at the central portion, which is integrally joined to the opening peripheral edge of the measurement opening 41, and the lower flange member 45. An upper part having a through-opening 47a (see FIG. 5) in the central part, which is integrally joined to the upper part of the valve member 46, preferably consisting of a ball valve, and detachably joined to the upper part of the valve member 46. The liquid level gauge 44 is integrally attached to the upper flange member 47.

  In this embodiment, the digging machine main body 11 of the muddy water type shield machine 10 has substantially the same configuration as the digging machine main body of a muddy type shield machine provided with a conventional air chamber, as shown in FIGS. ing. That is, the excavator main body 11 is disposed at the outer shell 30 formed in a cylindrical shape (cylindrical shape) and the distal end portion of the excavator main body 11, and by a known cutter rotation drive mechanism (not shown). The cutter head 12 that is controlled to rotate and excavates the face 20, the cutter-side partition wall 16 that is formed in the outer shell 30 and is spaced apart from the cutter head 12 in the direction opposite to the digging direction, and the cutter-side partition wall 16 digs up. The main body side partition wall 17 is formed in the outer shell 30 so as to be spaced apart in the opposite direction.

  The cutter-side partition wall 16 is composed of a disk-shaped partition plate formed so as to partition the inside of the outer shell body 30 in the front and rear direction in the digging direction. The main body side partition wall 17 disposed behind the cutter side partition wall 16 is composed of a partition plate having a substantially annular donor plate shape with a central portion cut out in a circular shape and a lower end portion cut out in an arcuate shape (FIG. 2). reference). A cylindrical inner cylinder 31 is fitted inside the central portion of the main body-side partition wall 17 cut into a circle. The inner cylinder 31 is integrally joined to the main body side partition wall 17 in a state of extending to the back surface of the cutter side partition wall 16 and being in close contact therewith (see FIG. 1). A bottom plate 32 is provided at the lower end portion of the main body-side partition wall 17 that is notched in an arcuate shape. The bottom plate 32 forms a flat bottom portion inclined toward the cutter chamber 13 in the air chamber 14. The bottom plate 32 extends to the back surface of the cutter side partition wall 16 and is in close contact with the main body side partition wall 17 while being in close contact therewith.

  As a result, between the cutter side partition wall 16 and the main body side partition wall 17, a substantially annular donor-shaped air chamber 14 with a lower end portion cut out is formed, similar to the conventional muddy shield shield machine having an air chamber. Is done. The air chamber 14 communicates with the cutter chamber 13 through a communication port 18 formed in the lower portion of the cutter-side partition wall 16 at a portion directly above the bottom plate 32 that covers the bottom. Thus, muddy water is sent from the cutter chamber 13 to the air chamber 14, and a muddy water layer 19 is formed in a substantially lower half portion below the air layer 15. Further, the inner chamber 31 provided in the central portion of the air chamber 14 in the radial direction is provided with gears, motors, and the like, similar to the muddy water shield machine equipped with the conventional air chamber. A known cutter rotation drive mechanism (not shown) is provided.

  Moreover, in this embodiment, the mud pipe 33 which sends mud to the cutter chamber 13 in the excavator main body 11 of the mud type shield machine 10 and the mud pipe 34 which discharges mud together with excavated soil from the cutter chamber 13. With.

  The mud pipe 33 is attached to the upper part of the main body side partition wall 17 and the cutter side partition wall 16 so as to pass through these from the rear side of the main body side partition wall 17 so that the tip opening is opened at the upper part of the cutter chamber 13. The mud feeding pipe 33 feeds mud water toward the cutter chamber 13 by driving a mud feeding pump (not shown), for example, from a mud tank or mud tank (not shown) installed in a shaft or tunnel. Mud can be used.

  The mud discharge pipe 34 is attached below the bottom of the air chamber 14 partitioned by the bottom plate 32 so as to penetrate the cutter side partition wall 16 and open at the bottom of the cutter chamber 13 at the rear end. The drainage pipe 34 drives a drainage pump (not shown), for example, for mud tanks and mud tanks (not shown) installed in shafts or tunnels to mix mud mixed with excavated soil. It can be discharged from the cutter chamber 13.

  Then, mud is sent to the cutter chamber 13 through the mud pipe 33, and the mud is discharged from the cutter chamber 13 together with the excavated soil through the mud pipe 34, and then a mud tank or mud tank (shown). The tunnel is dug while the face 20 is excavated by the cutter head 12 while mud is circulated between them. The mud pump and the mud pump are connected to a known control device (not shown) for controlling the amount of mud and the amount of mud discharged in the same manner as the conventional mud shield shield machine equipped with an air chamber. For example, based on the detection result by the muddy water pressure detector 50 provided in the cutter chamber 13, the amount of mud and the amount of muddy water can be controlled so that the muddy water pressure in the cutter chamber 13 becomes a predetermined value. ing.

  Further, in the present embodiment, the excavator body 11 of the muddy water type shield excavator 10 includes an air supply pipe 24 that pumps air to the air layer 15 in the air chamber 14 and an exhaust pipe that discharges air from the air layer 15. 35 is provided through the main body side partition wall 17 in the upper part of the main body side partition wall 17.

  An air tank 22 for storing compressed air and an air compressor 23 for generating compressed air are connected to the air supply pipe 24, and an air supply pressure reducing adjustment valve 25 and an air supply side air control valve 26 are provided. It has been. The air supply pipe 24 is preferably provided with an air supply decompression adjustment valve 25 or an air supply side so that the air pressure of the air layer 15 in the air chamber 14 is maintained at a predetermined pressure when a normal tunnel is dug. The air control valve 26 is controlled by a known control device (not shown) so that compressed air can be continuously fed from the air tank 22 to the air layer 15. Further, when a sudden drop or rise in the muddy water pressure in the cutter chamber 13 or the air pressure in the air layer 15 in the air chamber 14 is detected by the muddy water pressure detector 50 or the in-chamber air pressure detector 27, or a liquid described later. When it is detected by detecting a drop or rise in the liquid level 19a of the muddy water layer 19 by the surface gauge 44, it is preferable to control the air supply decompression adjustment valve 25 and the air supply side air control valve 26 with a control device (not shown). ) To increase or decrease the amount of compressed air sent to the air layer 15 so that the air pressure of the air layer 15 can be quickly recovered so that the air pressure becomes a predetermined pressure. It has become.

  The exhaust pipe 35 is provided with an exhaust-side air control valve 38. The exhaust pipe 35 is preferably an air supply side air control valve of the air supply pipe 24 so that the air pressure of the air layer 15 in the air chamber 14 is maintained at a predetermined pressure when the tunnel is dug. 26, the exhaust side air control valve 38 is controlled by a known control device (not shown), so that a desired amount of air can be continuously discharged from the air layer 15. Further, when a sudden drop or rise in the muddy water pressure in the cutter chamber 13 or the air pressure in the air layer 15 in the air chamber 14 is detected by the muddy water pressure detector 50 or the in-chamber air pressure detector 27, or a liquid described later. When detected by detecting a drop or rise in the liquid level of the muddy water layer 19 by the surface gauge 44, the exhaust side air control valve is preferably interlocked with the air supply side air control valve 26 of the air supply pipe 24. 38 is controlled by a known control device (not shown) so that the amount of air discharged from the air layer 15 is decreased or increased so that the air pressure of the air layer 15 becomes a predetermined pressure. It can be recovered quickly.

  In the present embodiment, a liquid level gauge installation chamber 40 is formed on the bottom surface portion 40a of the main body side partition wall 17 so as to project from the main body side partition wall 17 to the cutter side partition wall side 16. Is disposed in a portion directly above the liquid surface 19 a of the muddy water layer 19. In the liquid level gauge installation chamber 40, a liquid level gauge 44 is installed in a state in which a reflected wave from the liquid level 19a of the muddy water layer 19 in the air chamber 14 can be directly detected.

  That is, the liquid level gauge 44 opens and closes the hollow measurement path 42 from the measurement opening 41 to the liquid level gauge 44 so that the pressurized air forming the air layer 15 does not leak from the measurement opening 41. It is detachably attached to the level gauge installation chamber 40 through a valve mechanism 43 having a function to perform. As shown in FIGS. 3A and 3B, the valve mechanism 43 is integrally joined to the opening peripheral portion of the measurement opening 41 formed in the bottom surface portion 40 a of the liquid level gauge installation chamber 40. A lower flange member 45 having a through-opening 45a (see FIG. 4), a valve member 46 composed of a ball valve joined integrally above the lower flange member 45, and a detachable integral with the valve member 46. And an upper flange member 47 having a through-opening 47a (see FIG. 5) in the central portion. The liquid level gauge 44 is integrally attached to the upper flange member 46.

  Here, the level gauge installation chamber 40 is made of steel having a hollow hexahedron shape having a width b of about 400 to 500 mm, a depth d of about 300 to 450 mm, and a height h of about 500 to 700 mm. One side surface which is formed as a box and is disposed along the main body side partition wall 17 is an opening surface 40b. The liquid level gauge installation chamber 40 is tightly joined by welding or the like to the peripheral edge of the opening surface 40b to the peripheral edge of the opening window 17a (see FIG. 1) for attaching the liquid level gauge formed on the main body side partition wall 17. By doing so, it is fixed to the upper part of the main body side partition wall 17 in an airtight manner in a state of protruding from the main body side partition wall 17 to the cutter side partition wall side 16 at a position avoiding the portion directly above the inner cylinder 31. As a result, the measurement opening 41 formed in the bottom surface portion 40 a of the liquid level gauge installation chamber 40 is arranged at a portion immediately above the liquid surface 19 a due to the muddy water layer 19 inside the air chamber 14.

  In the present embodiment, the level gauge installation chamber 40 in which the level gauge 44 is installed is located on both sides of the inner cylinder 31 provided in the central portion of the air chamber 14 as shown in FIG. , 2 places each, 4 places in total. Since the liquid level gauge setting chambers 40 are provided on both sides of the air chamber 14 with the central part interposed therebetween, the water level of the liquid level 19a of the muddy water layer 19 is detected by the liquid level gauges 44 on both sides of the central part. It is possible to measure the average value, and manage the state of the muddy water 21 (viscosity, variation, etc. of the muddy water 21) by measuring the difference in water level between the liquid level gauges 44 on both sides of the central portion. It becomes possible to do. Since two level gauge installation chambers 40 are provided on both sides of the central portion of the air chamber 14, the liquid level gauges 44 installed in these level gauge installation chambers 40 are complemented with each other. Thus, for example, when one of the liquid level gauges 44 becomes dirty or becomes in need of maintenance, the other liquid level gauge 44 can continuously measure the water level of the liquid level 19a of the muddy water layer 19. .

  In the present embodiment, the lower flange member 45 constituting the valve mechanism 43 is, for example, a steel annular donut-shaped thick plate-like member as shown in FIGS. 3 (a), 3 (b) and FIG. A through-opening 45a is formed in the central portion. Further, a steel joining sleeve 45b is integrally attached to the lower flange member 45 so as to protrude downward from the opening edge of the through opening 45a (see FIG. 3B). By joining the lower end portion of the joining sleeve 45b to the opening peripheral edge portion of the measurement opening 41 of the liquid level gauge installation chamber 40, the lower flange member 45 is floated from the bottom surface portion 40a of the liquid level gauge installation chamber 40. Then, it is integrally and airtightly joined to the opening peripheral edge of the measurement opening 41 via the joining sleeve 45b. Further, the lower flange portion 46a of the valve member 46 is joined to the upper surface of the lower flange member 45 in an airtight manner by welding joining, adhesive joining or the like.

  In this embodiment, the valve member 46 is a ball valve. The ball valve is a known valve member including a spherical valve body in which a through-hole having an opening cross-sectional area having a considerable size is formed through a central portion in a diameter direction. The pole valve operates the handle portion 46c so that the axial center of the through hole of the valve body is aligned with the axial center of the hollow flow path on both sides sandwiching the valve body, thereby communicating the hollow flow paths on both sides. By arranging the axis of the through hole of the valve body in the direction perpendicular to the axis of the hollow channel on both sides, the hollow channel on both sides is shut off in a sealed state.

  A lower flange portion 46a having a bolt fastening hole 48 formed at a lower end portion thereof and an upper flange portion 46b having a bolt fastening hole 48 formed at an upper end portion thereof are integrally attached to the valve member 46, respectively. It has been. As described above, the valve member 46 is integrally joined to the upper side of the lower flange member 45 via the lower flange portion 46a, and the upper flange member to which the liquid level gauge 44 is attached via the upper flange portion 46b. 47 is integrally joined to the upper part of the valve member 46 so as to be detachable.

  As shown in FIGS. 3 (a), 3 (b) and 5, the upper flange member 47 is an annular donut-shaped thick plate member made of, for example, steel, and a through-opening 47a is formed in the central portion thereof. ing. Further, a plurality of bolt fastening holes 49 are formed in the upper flange member 47 at positions corresponding to the bolt fastening holes 48 formed in the upper flange portion 46b of the valve member 46 at a predetermined interval in the circumferential direction. Has been. The upper flange member 47 matches the bolt fastening hole 49 with the bolt fastening hole 48 formed in the upper flange portion 46b of the valve member 46, and tightens the fastening bolt 50, whereby the upper flange member 47 is formed on the upper surface of the upper flange portion 46b. The liquid level gauge 44 and the liquid level gauge 44 are detachably and integrally joined together. On the upper surface of the upper flange member 47, a liquid level gauge 44 is integrally attached so as to close the through opening 47a.

  The liquid level gauge 44 is known as a measuring instrument that detects a reflected wave from the liquid level and measures the water level of the liquid level. For example, the liquid level gauge 44 emits an ultrasonic wave from the emitting unit toward the liquid level 19a of the muddy water layer 19. In addition, it is preferable to use various known ultrasonic liquid level gauges that can detect the ultrasonic wave reflected from the liquid level 19a of the muddy water layer 19 and measure the water level of the muddy water layer 19 by the receiving part. Can do.

  As shown in FIGS. 3 (a) and 3 (b), the liquid level gauge 44 is welded and joined, for example, with a joining flange 44a provided at the lower end of the level gauge 44 so as to cover the through opening 47a (see FIG. 5). By being airtightly bonded to the upper surface of the upper flange member 47 by adhesive bonding or the like, the upper flange member 47 is integrally attached to the upper flange member 47 while standing from the upper surface of the upper flange member 47. In addition, the emission part and the wave receiving part of the liquid level gauge 44 are formed in communication between the liquid level gauge 44 and the measurement opening 41 of the bottom surface part 40a of the liquid level gauge installation chamber 40 in the vertical direction. Further, an opening break of a considerable size is formed by the through opening 45a of the lower flange member 45, the through hole of the valve body of the valve member 46 and the hollow flow passages on both sides of the valve body, and the through opening 47a of the upper flange member 47. It will be arranged in a state facing the hollow measurement path 42 having an area.

  In this embodiment, during tunnel tunneling by the muddy water type shield machine 10, the shaft center of the through hole formed in the valve body of the valve member 46 by the ball valve is connected to the hollow flow path on both sides of the valve body. By being along the axial center, the hollow measurement path 42 having an opening cross-sectional area of a considerable size is made open over its entire length. As a result, an ultrasonic wave is preferably emitted from the liquid level gauge 44 toward the liquid level 19a of the muddy water layer 19 inside the air chamber 14 through the open hollow measurement path 42, and the liquid in the muddy water layer 19 is also emitted. By detecting the ultrasonic wave reflected from the surface 19a at the receiving part, the water level of the muddy water layer 19 is constantly leaked from the air layer 15 in the air chamber 14 to the inner side of the tunnel. It becomes possible to measure directly. In addition, since the water level of the muddy water layer 19 can be always directly measured by the liquid level gauge 44, for example, when the tunnel is being dug, water flow on the face 20 or mud pipe blockage occurs. When the pressure in the cutter chamber 13 or the air chamber 14 suddenly drops or rises, the liquid level 19a of the muddy water layer 19 in the air chamber 14 drops or rises. It is possible to immediately detect a drop or rise in the water level without causing a time delay, and the compressed air is sent from the air tank 22 to the air layer 15, for example, the pressure in the cutter chamber 13 or the air chamber 14. By increasing the amount, it is possible to recover quickly.

  On the other hand, for example, when the tunnel leveling by the muddy water type shield machine 10 is carried out over a long period of time, the liquid level gauge 44 breaks down, becomes dirty, or requires maintenance and inspection, the handle 46c is operated. If the axial center of the through hole formed in the valve body of the valve member 46 by the ball valve is disposed in a direction perpendicular to the axial center of the hollow flow path on both sides of the valve body, the bottom surface portion of the level gauge installation chamber 40 The hollow measurement path 42 extending from the measurement opening 41 of 40a to the liquid level gauge 44 is airtightly shut off in a state in which the pressurized air from the air layer 15 in the air chamber 14 does not leak out to the inside of the tunnel. It becomes possible to do. Thereby, the liquid level gauge 44 and the upper flange member 47 together with the upper flange member 47 are moved from the inner side of the tunnel, preferably under atmospheric pressure, without an operator entering the air chamber 14. The liquid level gauge 44 can be easily exchanged, cleaned, and inspected by removing the liquid level gauge from the liquid level gauge.

  Therefore, according to the muddy water type shield machine 10 including the air chamber 14 of the present embodiment, for example, when the pressure in the cutter chamber 13 or the air chamber 14 suddenly drops or rises, the pressure drops or rises. It is possible to immediately detect a drop or rise in the level of the liquid surface 19a of the mud layer 19 in the air chamber 14 using the liquid level gauge 44 without causing a time delay, and in the air chamber 14 Therefore, it is possible to replace the liquid level gauge 44 and to perform maintenance and inspection without an operator entering.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, a valve mechanism having a configuration different from that of the above embodiment can be adopted, and the valve member of the valve mechanism is not necessarily a ball valve. Various other known valve members capable of closing a hollow measurement path having a considerably large opening cross-sectional area in an airtight and openable manner can be used. In addition, the level gauge setting chambers in which the level gauges are installed do not necessarily have to be provided at two locations on both sides of the center portion of the cutter chamber, and may be provided at one location on each side. It is also possible to measure the water level of the liquid level of the muddy water layer by providing only one liquid level gauge installation room inside the cutter chamber.

DESCRIPTION OF SYMBOLS 10 Muddy water type shield machine 11 Engraver machine body 12 Cutter head 13 Cutter chamber 14 Air chamber 15 Air layer 16 Cutter side partition wall 17 Body side partition wall 18 Communication port 19 Muddy water layer 19a Liquid surface 20 Face surface 27 In-chamber air pressure detector 40 Liquid Surface meter installation chamber 40a Bottom surface portion 40b Opening surface 41 Measuring opening 42 Hollow measuring path 43 Valve mechanism 44 Level gauge 45 Lower flange member 45a Through opening 46 Valve member (ball valve)
46a Lower flange portion 46b Upper flange portion 46c Handle portion 47 Lower flange member 47a Through opening 50 Muddy water pressure detector

Claims (5)

It is formed between the cutter side partition wall and the cutter head, which is partitioned by a cutter head provided at the tip of the excavator body and excavating the face, and a cutter side partition wall arranged behind the cutter head. The cutter chamber, and an air chamber formed between the main body side partition and the cutter side partition, the partition chamber being partitioned by a main body side partition disposed behind the cutter chamber, In a muddy water type shield excavator that excavates a tunnel while stabilizing the face by the pressure of muddy water filled in
The air chamber and the cutter chamber communicate with each other through a communication port provided in the lower part of the cutter-side partition wall so that a muddy water layer is formed in the lower part of the air chamber and an air layer is formed in the upper part. In addition, tunnel excavation can be performed while mitigating pressure fluctuation on the ground surface on the face surface by compressive expansion of air in the air layer in the air chamber,
At the upper part of the main body side partition wall, the liquid level gauge installation chamber projects from the main body side partition wall to the cutter side partition wall side, and the measurement opening formed in the bottom surface part is arranged in the part directly above the liquid level of the muddy water layer Is provided,
In the liquid level gauge installation chamber, a valve mechanism that opens and closes a hollow measurement path between the measurement opening and the sealing opening is interposed to detect a reflected wave from the liquid level of the muddy water layer and to detect the muddy water layer. A muddy water shield machine with a detachable level gauge for measuring the water level. The valve mechanism includes a lower flange member having a through-opening at a central portion integrally joined to an opening peripheral portion of the measurement opening, a valve member integrally joined above the lower flange member, and the valve member An upper flange member having a through-opening at a central portion, which is detachably joined to the upper portion of the upper flange member, and the liquid level gauge is integrally attached to the upper flange member. The muddy water shield machine described. The muddy water type shield machine according to claim 2, wherein the valve member is a ball valve. The muddy water shield machine according to any one of claims 1 to 3, wherein the liquid level gauge is an ultrasonic liquid level gauge. The muddy water type shield machine according to any one of claims 1 to 4, wherein the liquid level gauge installation chambers in which the liquid level gauge is installed are respectively provided on both sides of a central portion of the air chamber. .

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