In-chamber sample recovery device and sample recovery method for shield machine

Abstract

To provide an in-chamber sample recovery device in a shield machine and a sample recovery method capable of sampling excavated earth and sand over the entire tunnel cross section during tunnel excavation by the shield machine, and capable of appropriately managing a mud additive contained in the excavated earth and sand.SOLUTION: The in-chamber sample recovery device in the shield machine comprises: openings 30 provided at a plurality of locations including at least an upper portion in a chamber partition wall 20 of the shield machine; sample collection means 40 connected to the openings 30 respectively; opening opening / closing means (first ball valve 42) for opening and closing the opening 30; and communication opening / closing means (air release ball valve 52) for converting a communication recovery state in which the sample in the chamber can be recovered and a communication closed state in which the sample in the chamber cannot be recovered by opening and closing a rear end side of the sample collection means 40.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a sample recovery device and a sample recovery method in a chamber of a shield machine, and more specifically, to a device and a method for recovering excavated soil and sand taken into the cutter chamber (hereinafter referred to as the chamber) of an earth pressure shield machine through a bulkhead (chamber partition). [Background technology]

[0002] The earth pressure shield tunneling method uses a closed shield machine, and the soil excavated by the cutter head is taken into a chamber and filled there, stabilizing the tunnel face. There are two types of earth pressure shield tunneling: earth pressure shield tunneling and muddy earth pressure shield tunneling. The earth pressure shield tunneling method collects the soil at the tunnel face into a chamber, adjusts the pressure using a screw conveyor that discharges the soil, and stabilizes the tunnel face by maintaining a balance between the excavated soil taken into the chamber and the earth pressure at the tunnel face. The muddy earth pressure shield tunneling method adds water, muddy water, additives, air bubbles, etc. to the excavated soil and stirs it to plastically fluidize it, which is then collected in the chamber, stabilizing the tunnel face.

[0003] In the earth pressure shield method, in order to maintain the earth pressure necessary to stabilize the face and discharge the appropriate amount of soil as the shield machine excavates, the excavated soil taken into the chamber must have appropriate plastic fluidity and be watertight to prevent groundwater from flowing into the chamber.

[0004] Since the properties of the excavated soil in the chamber have a large effect on the stability of the tunnel face during the excavation of a shield machine, it is necessary to properly grasp the properties of the excavated soil. Various techniques for grasping the properties of the excavated soil in the earth pressure shield tunneling method have been disclosed (for example, see Patent Documents 1 to 4).

[0005] The technology described in Patent Document 1 (JP Patent No. 3949024) relates to an excavation soil sampling device for use in a pressure chamber or soil discharge device when excavating a tunnel with an earth pressure shield machine. This soil sampling device includes a cylindrical body connected to a partition or the cylindrical casing of a screw type soil discharge device via an inlet side opening and closing member, a soil extraction screw blade rotatably arranged inside the cylindrical body, a rotary drive member for rotating the screw blade, and an outlet side opening and closing member provided on the outlet side of the cylindrical body.

[0006] The techniques described in Patent Document 2 (JP Patent No. 5876378) and Patent Document 3 (JP Patent No. 5922996) relate to a technique for sampling soil in the ground in front of a shield machine and setting the excavation conditions for the shield machine. This soil sampling device has through holes formed in the shield bulkhead and the cutter head. A boring pipe is protruded into the ground from the through hole formed in the cutter head, and the boring pipe that penetrates the chamber is rotated to excavate soil in the ground, thereby sampling the soil. The soil sampling is performed when the shield machine is stopped (when the cutter head stops rotating).

[0007] The technology described in Patent Document 4 (Patent Publication No. 2882481) is a technology for taking samples of mud or mud during excavation by an earth shield machine or a muddy water shield machine, and extracting and analyzing the gas components contained in the samples. This formation gas detection device for use in both muddy water and earth shield excavation is equipped with a sample suction and exhaust system, a sample circulation system, and a gas analyzer.

[0008] The sample intake and exhaust system is composed of a sample intake and exhaust pipe that takes in the soil excavated by the rotary cutter as a muddy water sample or muddy soil sample, and a sample intake and exhaust pump that sucks in and discharges the collected sample taken in through the sample intake and exhaust pipe and transfers it to the sample circulation system for the subsequent process by switching the valve. The sample circulation system has a sand trap that separates and removes solids contained in the sample, and a gas extractor that is filled with water and kept under vacuum, and is connected to the sample intake and exhaust system via a valve mechanism. The gas analyzer calculates the amount of harmful gases such as methane contained in the natural soil. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 3949024 [Patent Document 2] Patent No. 5876378 [Patent Document 3] Patent No. 5922996 [Patent Document 4] Patent No. 2882481 Summary of the Invention [Problem to be solved by the invention]

[0010] In recent years, tunnel excavation at great depths using large-diameter shield machines has become widespread, and it is sometimes impossible to analyze the properties of the excavated soil over the entire tunnel cross section using only samples taken from a screw conveyor that discharges the excavated soil taken into the chamber, as was done in the past. In other words, in large-diameter tunnels, the properties of the excavated soil can differ at the lower, middle, and upper levels of the tunnel face, and only the properties of the excavated soil at the lower level (lower level) of the tunnel can be determined using only samples taken from the screw conveyor that discharges the soil from the lower level (lower level) of the chamber.

[0011] For example, with a shield machine with a diameter of about 2 to 3 m, the properties of the excavated soil over the entire tunnel cross section can be roughly understood by analyzing the properties of the excavated soil using samples collected from a screw conveyor. However, with a shield machine with a diameter of over 10 m, it is difficult to say that the properties of the excavated soil over the entire tunnel cross section can be understood unless samples are collected not only from the lower part (lower part) of the face but also from the upper and middle parts.

[0012] In addition, in the earth pressure shield method, it is necessary to adjust the amount of mud-adding material contained in the excavated soil taken into the chamber to properly manage the plastic fluidity of the soil. Furthermore, when the mud-adding material is air bubbles, the air in the excavated soil taken into the chamber may accumulate at the top of the chamber because air has a smaller specific gravity than the soil. In such a case, the air that has accumulated at the top of the chamber must be discharged in order to ensure the plastic fluidity of the excavated soil taken into the chamber. The phenomenon of air accumulating at the top of the chamber is particularly likely to occur with large-diameter shield machines, and there is a concern that even if management is performed with great care, an event may occur in which the excavated soil cannot be properly recovered.

[0013] The soil sampling device described in Patent Document 1 has an opening in an inlet opening / closing valve provided in a partition (a nozzle portion formed above the partition) at a different position from that of the screw-type soil discharge device. Also, a screw blade for taking soil into the soil sampling device protrudes from the partition into the chamber. That is, the soil sampling device described in Patent Document 1 uses a screw blade (screw conveyor) to collect the excavated soil taken into the chamber, but the position from which the soil to be sampled is collected is, for example, from an opening provided above the partition, and no consideration is given to the fact that the properties of the soil change depending on the sampling position.

[0014] The soil sampling devices described in Patent Documents 2 and 3 are configured to sample soil by projecting a boring pipe into the natural ground, and do not take into consideration the properties of the soil after it is taken into the chamber. In addition, the technology described in Patent Documents 2 and 3 requires that the rotation of the cutter head be stopped when sampling soil, which stops the shield tunneling work.

[0015] The technology described in Patent Document 4 is intended to detect methane gas and other gases contained in mud or muddy water samples, and is not intended to sample excavated soil and sand taken into a chamber and analyze its properties.

[0016] The present invention has been proposed in consideration of the above-mentioned circumstances, and aims to provide an apparatus and method for recovering excavated soil taken into the chamber of an earth pressure shield machine through the chamber partition, which makes it possible to sample the excavated soil over the entire cross section of a tunnel and also enables appropriate management of the mud-adding materials contained in the excavated soil. [Means for solving the problem]

[0017] The device and method for recovering samples from a chamber in a shield machine according to the present invention include a plurality of openings provided in a chamber partition of the shield machine, and a sample recovery means connected to each opening. In multiple locations The opening is provided with an opening opening / closing means for opening and closing the opening, and further, a communication opening / closing means for opening and closing the rear end of the sample recovery means is provided on the rear end side of the sample recovery means. Then, by opening the opening opening / closing means and the communication opening / closing means, the sample in the chamber is recovered into the sample recovery means. On the other hand, by closing the opening opening / closing means and the communication opening / closing means, the sample is not taken into the sample recovery means from inside the chamber.

[0019] and, The chamber partition has openings at a plurality of locations, each opening being at a different distance from the center of the chamber partition. There is With this configuration, samples can be collected from openings located at different distances from the center of the chamber partition.

[0020] The opening may also be located on the spring line. Effect of the Invention

[0022] In the device and method for recovering samples from a chamber in a shield machine according to the present invention, samples are taken from the chamber through openings provided at multiple locations including at least the upper part of the chamber partition. Therefore, samples can be taken not only from the lower part (lower part) of the tunnel face, but also from the upper and middle parts, and the properties of the excavated soil over the entire cross section of the tunnel can be accurately grasped. In particular, in a large-section shield tunnel exceeding 10 m, where the properties of the excavated soil are not necessarily uniform over the entire surface of the tunnel face, accurate understanding of the properties of the excavated soil over the entire cross section makes it possible to appropriately manage the excavation of the shield machine.

[0023] In addition, by properly managing the muddy materials contained in the excavated soil and sand taken into the chamber, Ensures the plastic flow of the excavated soil taken into the chamber. It becomes possible. [Brief description of the drawings]

[0024] [Figure 1] FIG. 2 is an explanatory diagram of a chamber partition of a shield machine to which an in-chamber sample recovery device according to an embodiment of the present invention is applied, as viewed from the tail side. [Diagram 2] 2 is a longitudinal sectional view of the intra-chamber sample recovery device according to the embodiment of the present invention in a tunnel extension direction (a view taken along the line AA in FIG. 1). [Diagram 3] 3 is a longitudinal sectional view of the intra-chamber sample recovery device according to the embodiment of the present invention in a tunnel extension direction (viewed along the arrow BB in FIG. 2). [Figure 4]FIG. 2 is an enlarged view of the intra-chamber sample recovery device according to the embodiment of the present invention, as viewed from the tail side (an enlarged view of a portion of FIG. 1). [Diagram 5] FIG. 1 is a schematic diagram (1) of a mechanism for preventing clogging of a recovery pipe in an intra-chamber sample recovery device according to an embodiment of the present invention. [Figure 6] FIG. 2 is a schematic diagram (2) of a mechanism for preventing clogging of a recovery pipe in an intra-chamber sample recovery device according to an embodiment of the present invention. [Figure 7] FIG. 1 is a schematic diagram (1) of a mechanism for preventing eruptions in an in-chamber sample recovery device according to an embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram of a mechanism for preventing eruptions in an in-chamber sample recovery device according to an embodiment of the present invention (2). [Figure 9] FIG. 2 is a schematic diagram showing an installation position of an in-chamber sample recovery device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an in-chamber sample recovery device and a sample recovery method in a shield machine according to an embodiment of the present invention (hereinafter sometimes abbreviated as in-chamber sample recovery device and in-chamber sample recovery method) will be described with reference to the drawings.

[0026] 1 to 9 show an in-chamber sample recovery device according to an embodiment of the present invention, in which Figs. 1 to 4 are explanatory diagrams showing the structure of the in-chamber sample recovery device, Figs. 5 and 6 are schematic diagrams of a mechanism for recovering blockages in a recovery pipe, Figs. 7 and 8 are schematic diagrams of a mechanism for preventing eruptions, and Fig. 9 is a schematic diagram of an installation position of the in-chamber sample recovery device. Note that each figure is not a detailed design diagram of the in-chamber sample recovery device according to the present invention, but is intended to easily explain the embodiment, and the shapes and positions of members may differ slightly between each figure. In addition, the front side in the excavation direction of the shield machine may be referred to as the excavation direction front side, cutter head side, or natural ground side, and the rear side in the excavation direction of the shield machine may be referred to as the excavation direction rear side, tail side, or shield machine internal side.

[0027] <Outline of the in-chamber sample recovery device> The in-chamber sample recovery device 100 according to the embodiment of the present invention is a device for recovering samples from inside a chamber 10 in order to analyze the properties of excavated soil in the chamber over the entire cross section of a tunnel in an earth pressure shield tunneling method, and is particularly suitable for use with a large cross section shield machine with a diameter of more than 10 m. The earth pressure shield tunneling method to which the present invention is applied is particularly suitable for a mud earth pressure shield tunneling method and an air bubble shield tunneling method. Furthermore, the in-chamber sample recovery device 100 according to the embodiment of the present invention is provided with a mechanism for discharging air that has accumulated in the upper part of the chamber 10.

[0028] 1 to 4, this in-chamber sample recovery device 100 includes a plurality of openings 30 provided in a chamber partition 20 of the shield machine, and a sample recovery means 40 connected to each opening 30. The openings 30 are for recovering the excavated soil taken into the chamber 10, and are provided at a plurality of locations including at least the upper portion of the chamber partition 20. The sample recovery means 40 is connected in communication with the openings 30, and is a device for recovering the excavated soil taken into the chamber 10 via the openings 30.

[0029] <Opening> The openings 30 are provided so as to penetrate the chamber partition 20, and in the example shown in Fig. 1, they are provided in a total of four locations, namely, the top, left and right side portions, and near the center of the chamber partition 20. Note that Fig. 1 shows the chamber partition 20 as viewed from the tail side. Also, as shown in Fig. 9, it is preferable to provide openings 30 at multiple locations in the chamber partition 20, each at a different distance from the center of the chamber partition 20.

[0030] As shown in Figs. 2 to 4, the chamber partition 20 is provided with an attachment opening 31, and a blocking plate 32 for blocking the attachment opening 31 is attached to the inside of the shield machine of the attachment opening 31. As shown in Fig. 4, the blocking plate 32 is attached to the chamber partition 20 using a hinge 34 so as to be openable and closable, and the attachment opening 31 is normally in a closed state. A recovery pipe 41 is attached to the center of the blocking plate 32, penetrating the blocking plate 32. A recovery pipe support member 33 is attached to the attachment opening 31 on the chamber 10 side of the blocking plate 32, so as to be approximately flush with the chamber partition 20, and the recovery pipe support member 33 almost blocks the attachment opening 31 and is connected to the front end of the recovery pipe 41. The front end of the recovery pipe 41 is connected to the attachment opening 31. The recovery pipe 41 functions as a part of the sample recovery means 40.

[0031] In the above-mentioned example, the mounting opening 31, the recovery pipe support member 33, and the closure plate 32 function as the opening 30. These members are provided to reinforce the chamber partition 20 and the recovery pipe 41, and to facilitate maintenance. As shown in Figures 1 and 2, the mounting opening 31 is opened in the chamber partition 20, and the intra-chamber sample recovery device 100 is attached using the closure plate 32 or the like, but the front end of the recovery pipe 41 may be directly connected in communication with the mounting opening 31 provided in the chamber partition 20 without using the closure plate 32 or the like.

[0032] <Opening / Closing Means> As shown in Fig. 3, a first ball valve 42 functioning as an opening opening / closing means is attached to the recovery pipe 41 so as to be located on the opening 30 side of the sample recovery means 40. The first ball valve 42 shown in Fig. 3 is of the electric type, but may also be of the manual type.

[0033] As will be described in detail later, the chamber 10 is filled with excavated soil in a plastic flow state, and pressure is applied to stabilize the face. The pressure in the chamber 10 varies depending on the properties of the excavated soil, etc., but when the chamber 10 and the recovery pipe 41 are in communication with each other, a so-called eruption phenomenon may occur, and the excavated soil may spurt out from the joints of the recovery pipe 41 or the sample recovery section 44. For this reason, the first ball valve 42 of this embodiment is preferably an electrically operated valve whose opening degree can be adjusted. In other words, by gradually opening the first ball valve 42 rather than opening it all at once, the eruption phenomenon can be prevented.

[0034] 3, an emergency ball valve 43 is attached to the collection pipe 41 closer to the closure plate 32 than the first ball valve 42. This emergency ball valve 43 is manually operated and normally in an open state, and is closed by operating an opening / closing handle 43a when sample collection is to be stopped urgently. In this embodiment, the first ball valve 42 is the main component of the opening opening / closing means, but the emergency ball valve 43 is also an auxiliary component of the opening opening / closing means.

[0035] <Sample collection method> As shown in Figure 3, the sample recovery means 40 is connected in communication with the middle of the recovery pipe 41. This sample recovery means 40 is composed of a cylindrical sample recovery section 44 and a pair of pipe joints 45 for attaching and detaching the sample recovery section 44 to the recovery pipe 41. The pipe joints 45 are housing-type joints for connecting adjacent pipe members, and can connect the recovery pipe 41 and the sample recovery section 44 in series by attaching them to the outer periphery of the joint between the recovery pipe 41 and the sample recovery section 44 and tightening them with bolts and nuts.

[0036] That is, the recovery pipe 41 is divided into a front section and a rear section with the sample recovery section 44 in between, and the front end of the sample recovery section 44 is attached to the rear end of the front section of the recovery pipe 41 using a pipe joint 45, and the rear end of the sample recovery section 44 is attached to the front end of the rear section of the recovery pipe 41 using a pipe joint 45. Furthermore, as shown in Fig. 3, in order to strengthen the connection between the recovery pipe 41 and the sample recovery section 44, the outer periphery of the continuous recovery pipe 41 and the sample recovery section 44 may be tightened for reinforcement using a tightening bolt 46 (so-called tie bolt).

[0037] <Sample Collection Section> As described above, the sample recovery section 44 is made of a cylindrical member and is detachable from the recovery pipe 41. Therefore, a desired amount of sample can be recovered by replacing the sample recovery section 44. The sample recovery section 44 is formed, for example, from a translucent synthetic resin material, so that the sample recovered inside can be confirmed. Since the sample recovery section 44 is connected in communication with the inside of the chamber 10, it is necessary that the sample recovery section 44 has a strength sufficient to withstand the pressure inside the chamber 10. In addition, the inner and outer diameters, length, strength, etc. are appropriately set according to the amount of sample (excavated soil) to be recovered and the pressure inside the chamber 10.

[0038] <Communication opening / closing means> In this embodiment, the sample is collected in the sample collection section 44 through the collection pipe 41, but at this time, it is necessary to open the front end side of the collection pipe 41 and the rear end side of the sample collection section 44. That is, if the front end side of the collection pipe 41 is in a closed state, the sample does not flow in from the chamber 10, and if the rear end side of the sample collection section 44 is in a closed state, the pressure in the sample collection section 44 increases and the sample does not flow in. For this reason, in this embodiment, a communication opening and closing means is provided for converting between a communication collection state in which the sample in the chamber 10 can be collected and a communication closed state in which the sample in the chamber 10 cannot be collected by opening and closing the rear end side of the sample collection means 40 (sample collection section 44).

[0039] This communication opening and closing means is composed of an air vent ball valve 52 functioning as air vent means 50 described later, or a second ball valve 60 attached to the recovery pipe 41 located at the rear end side of the sample recovery means 40 (sample recovery section 44). In the example shown in Fig. 3, the second ball valve 60 attached to the recovery pipe 41 located at the rear end side of the sample recovery means 40 (sample recovery section 44) is manual, but it may also be electrically operated.

[0040] <Air removal method> As shown in Fig. 3, air vent pipe 51 connected to collection pipe 41 located at the rear end side of sample collection section 44 is provided with air vent means 50 for venting air remaining in chamber 10. As described above, this air vent means 50 is equipped with electric air vent ball valve 52 whose opening degree can be adjusted. The reason why the opening degree of air vent ball valve 52 is adjustable is to prevent an explosion phenomenon. A silencer 53 may be attached to the open end side of air vent means 50.

[0041] Since air has a smaller specific gravity than soil and sand, the air in the excavated soil and sand taken into the chamber 10 tends to remain in the upper part of the chamber 10. For this reason, the air venting means 50 needs to be provided at least in the upper part of the chamber partition 20.

[0042] In this embodiment, the air vent means 50 (air vent ball valve 52) also functions as the communication opening / closing means, but the second ball valve 60 provided at the rear end of the recovery pipe 41 may also function as the communication opening / closing means.

[0043] <Clearing the blockage of the collection pipe (opening)> When recovering a sample from within chamber 10, the sample may become clogged in recovery pipe 41 (including opening 30), causing recovery pipe 41 (opening 30) to become blocked. When recovery pipe 41 (opening 30) is blocked in this manner, it is not possible to recover the sample, and therefore it is necessary to unclog recovery pipe 41 (opening 30).

[0044] In order to eliminate the blockage of the recovery pipe 41 (opening 30), for example, as shown in FIG. 5, the recovery pipe 41 is opened at the rear side (opposite side to the opening 30) of the emergency ball valve 43, and a jet pipe 70 that jets air, water, etc. at high pressure is connected to this opening. Then, by injecting air or water into the recovery pipe 41 at high pressure, the blockage of the recovery pipe 41 (opening 30) is eliminated. A filling member (for example, a packer 71) that adheres to the opening is attached to the outer peripheral portion of the jet pipe 70, and by inserting the jet pipe 70 into the recovery pipe 41 (opening 30) from the opening, the blockage of the recovery pipe 41 (opening 30) is eliminated.

[0045] Also, as shown in FIG. 6, a shutter member 80 for opening and closing the opening 30 may be rotatably attached to the cutter head side of the chamber partition wall 20, and an opening / closing operation member (for example, a rotary handle 81) for operating the opening and closing of the shutter member 80 may be provided on the tail side of the chamber partition wall 20. Then, normally, the opening 30 is kept closed by the shutter member 80, and only when collecting a sample from the chamber 10, the opening 30 is opened by the shutter member 80, thereby preventing the blockage of the recovery pipe 41.

[0046] <Prevention of Eruption> As described above, when the chamber 10 and the recovery pipe 41 are in a communicating state, a so-called eruption phenomenon may occur, and there is a risk that the excavated soil and sand will blow out from the joints of the recovery pipe 41 and the sample collection unit 44. Therefore, one or both of the first ball valve 42 and the air vent ball valve 52, which are the opening / closing means for the opening or the communicating opening / closing means, can be adjusted in the opening amount, and by gradually opening the first ball valve 42 or the air vent ball valve 52, the occurrence of the eruption phenomenon is prevented. Further, an emergency ball valve 43 is provided in front of the opening / closing means for the opening (on the side of the chamber partition wall 20), so that the collection of the sample can be stopped urgently. In this case, one or both of the first ball valve 42 and the air vent ball valve 52, which are the opening / closing means for the opening or the communicating opening / closing means, or the emergency ball valve 43 functions as an eruption prevention means.

[0047] 7, a tank 90 for temporarily storing samples may be provided at the rear end of second ball valve 60 provided in recovery pipe 41 or at the rear end of the air vent pipe of air vent ball valve 52 functioning as air vent means 50 (rear end of silencer 53), thereby preventing the samples from scattering inside the shield machine (inside the tunnel) even in the unlikely event of an eruption. In the example shown in FIG. 7, tank 90 functions as the eruption prevention means.

[0048] Also, as shown in FIG. 8, a blocking member (sponge 91) for blocking the recovery pipe 41 may be packed in advance inside the recovery pipe 41 located in front of the sample recovery section 44. The blocking member (sponge 91) is flexible, and when a sample is recovered, it is pushed by the sample and moves from the front to the rear of the sample recovery section 44, and blocks the recovery pipe 41 located in the rear of the sample recovery section 44 when the sample recovery is completed. This prevents the occurrence of an eruption and prevents the sample from scattering inside the shield machine (inside the tunnel). In the example shown in FIG. 8, the sponge 91 functions as an eruption prevention means. Note that the blocking member is not limited to the sponge 91, and any member may be used as long as it can perform the above-mentioned function.

[0049] <How to collect samples from inside the chamber> Next, a description will be given of a method for recovering samples from a chamber using the above-mentioned chamber sample recovery device 100. The chamber sample recovery device 100 provides openings 30 at a plurality of locations in the chamber partition 20 of the shield machine (for example, in the example shown in FIG. 1, a total of four locations: the upper portion, the left and right sides, and the vicinity of the center; in the example shown in FIG. 9, a total of three locations: the top end, the inner peripheral side, and the outer peripheral side). DA recovery pipe 41 extending toward the inside of the machine (tail side) is connected. A sample recovery section 44 is detachably attached to the middle of the recovery pipe 41. A first ball valve 42 functioning as an opening opening / closing means is provided on the chamber bulkhead 20 side of the recovery pipe 41, and an air vent ball valve 52 functioning as a communication opening / closing means and an air vent means 50 is provided on the rear end side (tail side) of the recovery pipe 41.

[0050] Furthermore, the recovery pipe 41 is provided with an emergency ball valve 43 which is normally open and is located between the first ball valve 42 which functions as an opening opening / closing means and the chamber partition 20, and a manual second ball valve 60 which is normally closed is provided at the rear end (tail side) of the recovery pipe 41.

[0051] To recover a sample in the chamber 10 using the in-chamber sample recovery device 100 configured as described above, the first ball valve 42 functioning as the opening opening / closing means is gradually opened, and the air vent ball valve 52 functioning as the communication opening / closing means and the air vent means 50 is gradually opened, so that the opening 30 to the air vent means 50 (communication opening means) is in a communication recovery state. This allows the sample to be recovered from the chamber 10 to the sample recovery section 44. do It is possible.

[0052] Once the sample has been collected in the sample collecting section 44, the first ball valve 42 functioning as the opening opening / closing means is closed, and the air vent ball valve 52 functioning as the communication opening / closing means and the air vent means 50 is also closed to terminate (stop) the sample collection. If more samples are to be collected, the detachable sample collecting section 44 may be replaced and the above-mentioned sample intake procedure may be carried out.

[0053] In this embodiment, samples are collected from within the chamber 10 using intra-chamber sample collection devices 100 provided at multiple locations on the chamber partition 20, but the intra-chamber sample collection devices 100 used may be some or all of these. Similarly, even when the openings 30 are provided at different distances from the center of the chamber partition 20, the intra-chamber sample collection devices 100 used to collect samples from the chamber 10 can be appropriately selected. Note that, in order to collect samples from the lower part of the chamber 10, a screw conveyor (not shown) provided for collecting excavated soil and sand may be used.

[0054] Samples are normally collected from the chamber 10 about once a day. The frequency of sample collection is increased appropriately in cases where there is a risk of the mud-adding material being diluted by excessive water seepage from the tunnel face, where the soil quality of the excavated ground has changed and the previous amount of mud-adding is not enough to achieve plastic fluidity, where the soil in the chamber 10 has settled when the shield machine is restarted after a shutdown, or where the effect of the mud-adding material has decreased, etc.

[0055] Furthermore, when air accumulates in the chamber 10, the first ball valve 42 functioning as the opening opening / closing means is gradually opened, and the air vent ball valve 52 functioning as the air vent means 50 is gradually opened, so that the opening 30 is in a connected recovery state up to the air vent means 50. This makes it possible to vent the air that has accumulated in the chamber 10. Note that, although the intra-chamber sample retrieval device 100 used to vent the air from the chamber 10 is generally provided on the upper part of the chamber partition 20, the air that has accumulated in the chamber 10 may be vented using the intra-chamber sample retrieval device 100 provided in another position.

[0056] <Prevention of eruptions when removing air> When the air in the chamber 10 is removed, it is preferable to take measures to prevent an eruption using a device for preventing an eruption, as in the case of the above-mentioned sample recovery. This allows the air in the chamber 10 to be removed safely.

[0057] <Other embodiments> In this embodiment, the sample collection means 40 and the air extraction means 50 are integrated, but it is also possible to provide them separately. For example, although not shown in the drawings, there is a case where an air extraction section connected in communication with the opening 30 of the chamber partition wall 20 and a sample collection section 44 branched from the air extraction section are provided. Alternatively, there is a case where a sample collection section 44 connected in communication with the opening 30 of the chamber partition wall 20 and an air extraction section branched from the sample collection section 44 are provided. However, when they are provided separately, the equipment configuration becomes complicated, such as the need to provide members having the same function redundantly. Also, there is a risk that the sample may become clogged at the branch section, and in this case, the sample cannot be collected appropriately and reliably.

[0058] In this regard, in the in-chamber sample collection device 100 of this embodiment, the sample collection means 40 is linearly connected in communication with the opening 30, and there is no branch section in the flow path of the sample to be collected. Also, since the air extraction means 50 is provided at the rear end portion of the sample collection section 44 constituting the sample collection means 40, the sample collection means 40 and the air extraction means 50 are integrally configured. Therefore, the equipment configuration is simple, and since there is no branch section, there is no risk that the sample will become clogged at the branch section, and the sample can be collected appropriately and reliably. Also, the air staying in the chamber 10 (especially the upper portion of the chamber 10) can be efficiently extracted.

Description of reference numerals

[0059] 10 Chamber 20 Chamber partition wall 30 Opening 31 Mounting opening 32 Closing plate 33 Recovery pipe support member 34 Hinge 40 Sample collection means 41 Recovery pipe 42 First ball valve 43 Emergency ball valve 43a Opening / closing handle 44 Sample collection section 45 Pipe joint 46 Tightening bolt 50 Air extraction means 51 Air extraction pipe 52 Electric ball valve 53 Silencer 60 Second ball valve 70 Ejection pipe 71 Filling member (packer) 80 Shutter member 81 Rotating handle 90 Tank 91 Sponge 100 Chamber internal sample recovery device

Claims

1. A chamber partition wall of the shield machine has openings at a plurality of locations; Sample collection means connected to the openings, respectively; An opening opening / closing means for opening and closing the opening; a communication opening / closing means for opening and closing a rear end side of the sample recovery means to convert the chamber into a communication recovery state in which the sample in the chamber can be recovered and into a communication closed state in which the sample in the chamber cannot be recovered; Equipped with An in-chamber sample recovery device in a shield machine, characterized in that the openings are provided at multiple locations on the chamber partition, each at a different distance from the center of the chamber partition.

2. The opening is provided on the spring line.

2. The sample recovery device in a chamber of a shield machine according to claim 1.

3. A sample recovery means having a sample recovery portion is connected to each of a plurality of openings provided in a chamber partition of the shield machine; providing the openings at a plurality of locations on the chamber partition at different distances from a center of the chamber partition, thereby recovering the sample in the chamber from positions at different distances from the center of the chamber partition; an opening opening / closing means provided at the opening is set to an open state and a communication opening / closing means provided at the rear end of the sample recovery means is set to a communication recovery state, thereby recovering a sample from within the chamber to the sample recovery section; closing the opening opening / closing means provided at the opening and closing the communication opening / closing means provided at the rear end of the sample recovery means to stop recovery of the sample from within the chamber to the sample recovery section; A method for recovering samples from within a chamber in a shield machine.

4. The opening is provided on the spring line, 4. The method for recovering samples from within a chamber in a shield machine according to claim 3.

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