Measuring device and measuring method

Abstract

To provide a measuring device and a measuring method capable of accurately determining the amount of air present in excavated soil and sand in a chamber.SOLUTION: A measuring device 20 for measuring an amount of air Vc present in excavated soil and sand in a chamber 2a of a shield machine 1 includes a first pressure sensor 21 for detecting pressure in the chamber 2a containing the excavated soil and sand, a container 22 sealed with air at a predetermined pressure, a valve device 23 for connecting or disconnecting the chamber 2a and the container 22, and a second pressure sensor 24 for detecting pressure inside the container 22. By opening the valve device 23, the pressure in the chamber 2a and the pressure inside the container 22 are balanced.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a measurement device and a measurement method. [Background technology]

[0002] Patent Document 1 discloses a shield tunneling machine that performs the air bubble shield tunneling method. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-79771 Summary of the Invention [Problem to be solved by the invention]

[0004] In a shield tunneling machine such as that described in Patent Document 1, a preset amount of aerated material or water is supplied into the chamber as excavation work proceeds to increase the fluidity of the excavated soil and sand being discharged.

[0005] In order to properly carry out excavation work, it is preferable to accurately grasp the properties of the excavated soil in the chamber, in particular the moisture content and air content of the excavated soil in the chamber.

[0006] The amount of moisture present in the chamber can be calculated, for example, by comparing the wet density and dry density of the excavated soil. However, it is difficult to directly measure the amount of air present in the excavated soil in the chamber, and a method for accurately determining the amount of air present in the excavated soil in the chamber has been desired.

[0007] An object of the present invention is to provide a measuring device and a measuring method that can accurately determine the amount of air present in excavated soil in a chamber. [Means for solving the problem]

[0008] The present invention is a measuring device for measuring the amount of air present in the excavated soil in the chamber of a shield tunneling machine, and is equipped with a first pressure detector for detecting the pressure in the soil storage space that contains the excavated soil, an air-sealed space in which air of a predetermined pressure is sealed, a valve device that connects or disconnects the soil storage space and the air-sealed space, and a second pressure detector for detecting the pressure in the air-sealed space, and by opening the valve device, the pressure in the soil storage space and the pressure in the air-sealed space are balanced. [Effects of the Invention]

[0009] According to this invention, the amount of air present in the excavated soil in the chamber can be calculated based on the change in pressure before and after the valve device is opened, thereby providing a measuring device and a measuring method that can accurately grasp the amount of air present in the excavated soil in the chamber. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a shield machine to which a measuring device according to an embodiment of the present invention is applied. [Figure 2] FIG. 2 is a front view of the cutter head of the shield tunneling machine according to the embodiment of the present invention. [Figure 3] 1 is a schematic configuration diagram of a measurement device according to a first embodiment of the present invention. [Figure 4] 3 is a flowchart showing the flow of a measurement method of the measurement apparatus according to the first embodiment of the present invention. [Figure 5] FIG. 10 is a schematic configuration diagram of a modified example of the measurement device according to the first embodiment of the present invention. [Figure 6] FIG. 10 is a schematic configuration diagram of a modified example of the measurement device according to the first embodiment of the present invention. [Figure 7] FIG. 10 is a schematic configuration diagram of a measurement device according to a second embodiment of the present invention. [Figure 8] 10 is a flowchart showing the flow of a measurement method of a measurement apparatus according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] First Embodiment A measuring device 20 according to a first embodiment of the present invention will be described below with reference to the drawings.

[0012] The measuring device 20 is used to measure the amount of air present in the excavated earth and sand in the chamber 2a of the shield machine 1 (excavation propulsion machine).

[0013] First, with reference to Figure 1, we will explain the shield machine 1 (excavation propulsion machine) to which the measuring device 20 is applied. The shield machine 1 excavates underground (natural ground) to form an excavation hole, and constructs a shield tunnel T (tunnel) by assembling segment rings 9, which will be described later, to cover the inner wall of the excavation hole. In the following explanation, the face side, which is the direction in which the shield machine 1 advances, will be referred to as the "front," and the tunnel entrance side, which is the opposite direction, will be referred to as the "rear."

[0014] FIG. 1 is a cross-sectional view showing the schematic configuration of a shield machine 1, and FIG. 2 is a view of the shield machine 1 as seen from the front of FIG. 1, and is a front view of a cutter head 3. As shown in FIG.

[0015] The shield machine 1 of this embodiment is used in the air bubble shield method. As shown in Fig. 1, the shield machine 1 comprises a cylindrical skin plate 2 capable of supporting the inner wall W1 of the natural ground, a rotary cutter head 3 (cutter) attached to the skin plate 2, and a partition wall 4 provided inside the skin plate 2 and dividing the interior of the skin plate 2 in the front-to-rear direction. Inside the skin plate 2, segment rings 9 are constructed one after another as the shield machine 1 advances. Note that the cross-sectional shape of the skin plate 2 is not limited to being circular, and may be elliptical or rectangular.

[0016] The skin plate 2 is provided behind the cutter head 3. A jack 5 is fixed to the inner wall of the skin plate 2 behind the partition wall 4. The jack 5 receives a reaction force from the segment ring 9 and propels the skin plate 2 forward, pressing the cutter head 3 against the natural ground. When the skin plate 2 is propelled forward and the segment ring 9 comes out of the skin plate 2, a backfill material (not shown) is filled between the outer peripheral surface of the segment ring 9 and the inner wall W1 of the natural ground.

[0017] The cutter head 3 is a disk-shaped structure having an outer diameter approximately equal to that of the skin plate 2. As shown in Fig. 2, the cutter head 3 has hollow spoke portions 31 extending radially from the rotation axis C1 as the center, an annular ring portion 32 to which the tip ends of the spoke portions 31 are connected, openings 33 formed between adjacent spoke portions 31, and a plurality of cutter bits 34, 35 arranged at predetermined intervals in the circumferential and radial directions on the surfaces of the spoke portions 31 facing the excavation face (cutting face).

[0018] As shown in Fig. 1, the cutter head 3 is connected to a motor 6 via a cutter shaft 6a and a reduction mechanism 6b, and is driven to rotate in front of the skin plate 2 by the drive of the motor 6. When the cutter head 3 rotates while pressed against the ground, the ground is excavated by the cutter bits 34, 35.

[0019] A chamber 2a is formed between the cutter head 3 and the partition wall 4. Earth and sand generated by excavation by the cutter head 3 (hereinafter referred to as "excavated earth and sand") is introduced into the chamber 2a through an opening 33 (see FIG. 2) provided in the cutter head 3.

[0020] A stirring rod (not shown) protruding into the chamber 2a is provided on each spoke 31 of the cutter head 3. As the cutter head 3 rotates, the stirring rod stirs the excavated soil remaining in the chamber 2a.

[0021] As shown in Figure 1, the shield machine 1 is further equipped with a measuring device 20 that is attached to the partition wall 4 and that measures the amount of air present in the excavated soil in the chamber 2a. In addition to the measuring device 20, a resistivity meter (not shown) that detects the resistivity of the excavated soil in the chamber 2a, an earth pressure meter (not shown), and the like are also attached to the partition wall 4.

[0022] In addition, the partition 4 is provided with a screw conveyor 7 for discharging the excavated soil in the chamber 2a to the rear of the partition 4, and a plurality of fixed blades (not shown) that protrude into the chamber 2a to stir the excavated soil that has accumulated in the chamber 2a.

[0023] In the shield machine 1, by filling the chamber 2a with excavated earth and sand, earth pressure (earth pressure) is generated in the chamber 2a, which suppresses the earth pressure and groundwater pressure at the face and stabilizes the face. The earth pressure in the chamber 2a is adjusted by controlling the discharge amount of excavated earth and sand in the chamber 2a using the screw conveyor 7, or by controlling the excavation speed of the shield machine 1. The earth pressure in the chamber 2a can also be adjusted by injecting, for example, an aqueous solution (liquid) containing a mud-adding agent into the excavated earth and sand in the chamber 2a.

[0024] As shown in Figure 1, the shield machine 1 further includes an air bubble injection pipe 10 that injects air bubbles into the tunnel face in order to increase the fluidity of the excavated soil. One end of the air bubble injection pipe 10 is connected to an air bubble supply device (not shown) such as a pump, and the other end opens to the front of the cutter head 3.

[0025] The shield tunneling machine 1 excavates while injecting shaving cream-like foam, obtained by foaming a foaming agent in an air foam supply device, into the tunnel face. The foam injected into the tunnel face improves the fluidity and water-stopping properties of the excavated soil and prevents the excavated soil from adhering to the chamber 2a. This allows for smooth tunneling while maintaining the stability of the tunnel face. For example, an anionic surfactant is used as the foaming agent. Alternatively, the foam may be injected into the chamber 2a.

[0026] The shield machine 1 configured in this way excavates the natural ground by rotating the cutter head 3 while extending the jacks 5. A borehole is excavated in the natural ground, and the segment rings 9 are assembled one after another along the inner circumferential surface of the borehole to construct the shield tunnel T. By injecting backfill material into the gaps that form between the inner circumferential surface of the borehole and the outer circumferential surfaces of the segment rings 9, the segment rings 9 are firmly bonded to the natural ground via the backfill material.

[0027] In order to properly carry out excavation work in the shield tunneling machine 1, it is preferable to accurately grasp the amount of air in the excavated soil within the chamber 2a. Therefore, in this embodiment, the amount of air within the chamber 2a is measured using a measuring device 20. The measuring device 20 will be described in detail below with reference to Figures 3 and 4. Figure 3 is a structural cross-sectional view of the measuring device 20 taken along its axial direction, showing its general configuration.

[0028] As shown in Figure 3, the measuring device 20 includes a first pressure sensor 21 (first pressure detector) for detecting the pressure in a chamber 2a (soil storage space) containing excavated soil, a container 22 (air-sealed space) in which air at a predetermined pressure is sealed, a valve device 23 for connecting or blocking communication between the chamber 2a and the container 22, a second pressure sensor 24 (second pressure detector) for detecting the pressure in the container 22, a compressor 25 for supplying compressed air to the container 22, and a controller 40 for controlling the operation of the measuring device 20.

[0029] The first pressure sensor 21 is attached to the partition wall 4 and communicates with the chamber 2a through a pipe that penetrates the partition wall 4. Data on the pressure inside the chamber 2a detected by the first pressure sensor 21 is sent to the controller 40.

[0030] Container 22 is a pressure-resistant container that stores compressed air therein. The volume of the space within container 22 is preferably about one-tenth of the volume of the space within chamber 2a. Compressor 25 is connected to container 22 through piping 26. Note that piping 26 is provided with an on-off valve 27 that allows or blocks communication between compressor 25 and the space within container 22.

[0031] The valve device 23 is driven to open and close by a drive device (not shown) based on instructions from the controller 40. Under normal circumstances (when the measuring device 20 is not in use), the valve device 23 blocks communication between the chamber 2a and the container 22, so that excavated soil and sand in the chamber 2a does not flow into the container 22.

[0032] The second pressure sensor 24 detects the pressure inside the container 22. Data on the pressure inside the container 22 detected by the second pressure sensor 24 is sent to the controller 40.

[0033] The on-off valve 27 is driven to open and close based on instructions from the controller 40.

[0034] Next, a method for measuring the amount of air Vc present in the excavated soil in the chamber 2a using the measuring device 20 will be described with reference to the flowchart shown in Fig. 4. The process shown in the flowchart of Fig. 4 is executed based on a program stored in advance in the controller 40.

[0035] Measurement of the amount of air Vc present in the excavated earth and sand in the chamber 2a by the measuring device 20 is started by pressing a switch. Alternatively, measurement may be performed at predetermined time intervals.

[0036] In step S1, the pressure inside the container 22 is set to a predetermined value P1. Specifically, the controller 40 closes the valve device 23, opens the on-off valve 27, and drives the compressor 25. This causes compressed air to be supplied into the container 22, and the pressure inside the container 22 increases. Note that the predetermined value P1 is a pressure higher than the expected pressure inside the chamber 2a (for example, a pressure about 700 kPa higher than the pressure inside the chamber 2a).

[0037] When the controller 40 detects that the pressure inside the container 22 (the pressure detected by the second pressure sensor 24) has reached a predetermined value P1, it closes the on-off valve 27 to cut off communication between the compressor 25 and the container 22 and stops the compressor 25. If the pressure inside the container 22 has decreased during the lapse of a certain period of time (for example, several minutes) until the pressure inside the container 22 stabilizes, the on-off valve 27 is opened again and the compressor 25 is driven.

[0038] In step S2, the pressure inside the chamber 2a is detected. Specifically, the pressure inside the chamber 2a is detected by the first pressure sensor 21. Data on the detected pressure is sent to the controller 40.

[0039] In step S3, the valve device 23 is opened. Specifically, the controller 40 drives a drive device (not shown) to open the valve device 23, thereby connecting the chamber 2a to the container 22. This causes the compressed air in the container 22 to flow into the chamber 2a, and over time, the pressure in the chamber 2a and the pressure in the container 22 become equal to each other.

[0040] In step S4, the air volume Vc is calculated. Specifically, when the controller 40 determines that the pressure in the chamber 2a detected by the first pressure sensor 21 and the pressure in the container 22 detected by the second pressure sensor 24 have become equal, the controller 40 calculates the air volume Vc contained in the excavated earth and sand in the chamber 2a. The air volume Vc is the volume of air.

[0041] Here, a method for calculating the air amount Vc will be specifically described.

[0042] Chamber 2a contains excavated soil, water, air, etc. When valve device 23 is opened, compressed air in container 22 flows into chamber 2a, causing the pressure in chamber 2a to increase. The volumes of the excavated soil and water do not change substantially even when the pressure changes. Therefore, even if the pressure in chamber 2a increases, the volume of the parts of chamber 2a other than the excavated soil and water, i.e., the volume of the air contained in the excavated soil in chamber 2a, does not change.

[0043] Therefore, if the pressure when the pressure in chamber 2a and the pressure in container 22 are balanced is pressure Pa, the pressure in container 22 before opening valve device 23 is pressure Pb, the pressure in chamber 2a before opening valve device 23 is pressure Pc, the capacity of container 22 is capacity Vb, and the volume of air in chamber 2a is air volume Vc, the following equation 1 is established.

[0044] Pa×(Vb+Vc)= Pb×Vb+Pc×Vc (Formula 1) Here, the pressures Pa, Pb, and Pc are measured values detected by the first pressure sensor 21 and the second pressure sensor 24, and the capacitance Vb is a known value.

[0045] By substituting the pressures Pa, Pb, and Pc and the volume Vb into this equation 1, the air volume Vc can be easily calculated.

[0046] In this way, by using the measuring device 20 of this embodiment, the amount of air Vc present in the excavated earth and sand in the chamber 2a can be accurately and quickly determined.

[0047] Here, a modified example of the measuring device 20 according to the first embodiment will be described.

[0048] In the measuring device 20, when the valve device 23 is opened, air flows from the container 22 toward the chamber 2a, making it unlikely that the excavated soil in the chamber 2a will flow into the container 22. However, to more reliably prevent the excavated soil in the chamber 2a from flowing into the container 22, a filter 50 may be provided in the pipe connecting the container 22 and the chamber 2a, as shown in FIG. 5. As shown in FIG. 5, by providing the filter 50 closer to the chamber 2a than the valve device 23, it is possible to prevent the excavated soil from adhering to the sealing portion of the valve device 23. Note that the filter 50 may also be provided closer to the container 22 than the valve device 23.

[0049] 6, a check valve 60 may be provided in the pipeline connecting the container 22 and the chamber 2a. The check valve 60 allows air to flow from the container 22 toward the chamber 2a, while preventing excavated earth from flowing into the container 22 from the chamber 2a. As shown in FIG. 6, by providing the check valve 60 closer to the chamber 2a than the valve device 23, it is possible to prevent excavated earth from adhering to the sealing portion of the valve device 23. Note that the check valve 60 may also be provided closer to the container 22 than the valve device 23.

[0050] In the above embodiment, compressed air is supplied to the container 22, the valve device 23 is opened, and the pressure in the chamber 2a and the pressure in the container 22 are balanced to calculate the air volume Vc. However, this is not limiting. Specifically, the pressure in the container 22 may be set to atmospheric pressure, and the valve device 23 may be opened to balance the pressure in the chamber 2a and the pressure in the container 22. In this case, the air volume Vc contained in the excavated soil in the chamber 2a can be calculated based on the pressures in the chamber 2a and the container 22 before and after the valve device 23 is opened, and the above-mentioned Equation 1. Furthermore, in this case, the compressor 25 is not required. In this case, since air flows from the chamber 2a side toward the container 22, it is preferable to provide a filter 50 shown in FIG. 5. The pressure in the container 22 may also be set to negative pressure. In this case, the pressure difference between the pressure in the chamber 2a and the pressure in the container 22 can be made larger than when the pressure in the container 22 is set to atmospheric pressure.

[0051] 4 shows an example of a method for measuring the air volume Vc using the measuring device 20, and is not limited to this. For example, the order of step S1 and step S2 may be reversed.

[0052] The measuring device 20 according to the first embodiment described above provides the following advantages.

[0053] The measuring device 20 can easily and accurately measure (calculate) the amount of air Vc present in the excavated soil in the chamber 2a based on the changes in pressure in the chamber 2a and the pressure in the container 22 before and after opening the valve device 23.

[0054] Furthermore, by providing a filter 50 and a check valve 60 in the pipeline connecting the vessel 22 and the chamber 2a, the excavated earth and sand in the chamber 2a can be prevented from flowing into the vessel 22 more reliably.

[0055] Second Embodiment Next, a measuring device 120 according to a second embodiment of the present invention will be described with reference to FIGS.

[0056] The measuring device 120 according to the second embodiment differs from the measuring device 20 according to the first embodiment in that it includes a connecting device 70. The following description will focus on this difference, and the same components will be assigned the same numbers and descriptions thereof will be omitted as appropriate.

[0057] 7, the measuring device 120 includes a connecting device 70 that connects the chamber 2a and the container 22. The connecting device 70 has a cylinder 71 that penetrates the partition wall 4 that separates the chamber 2a and opens into the chamber 2a, a piston 72 (sliding member) that slides along the inner wall of the cylinder 71, a driving device 73 that drives the piston 72 to draw the excavated soil that has been taken into the chamber 2a into the cylinder 71, and a shutter 74 that connects or blocks communication between the cylinder 71 and the chamber 2a.

[0058] The cylinder 71 is formed of a cylindrical steel pipe or resin pipe. The cylinder 71 is attached to the partition wall 4 so that an opening on one end thereof communicates with the chamber 2a. The interior of the cylinder 71 is partitioned by a shutter 74 into a space S1 that is blocked from communication with the chamber 2a by the shutter 74, and a space S2 that is always in communication with the chamber 2a.

[0059] The piston 72 is formed of a cylindrical member having an outer diameter slightly smaller than the inner diameter of the cylinder 71. A seal member (not shown) is provided on the outer peripheral surface of the piston 72 to seal between the outer peripheral surface of the piston 72 and the inner peripheral wall of the cylinder 71.

[0060] The driving device 73 is a fluid pressure cylinder having a rod 73a. The driving device 73 is attached to the other end (rear side) of the cylinder 71.

[0061] A piston 72 is attached to the tip of the rod 73a. As the drive unit 73 extends and retracts, the piston 72 moves between a forward position at one end of the cylinder 71 (toward the chamber 2a) and a backward position at the other end of the cylinder 71, where the piston 72 draws the excavated soil in the chamber 2a into the space S1 of the cylinder 71.

[0062] The shutter 74 is driven to open and close by a drive device (not shown) based on instructions from the controller 40. When closed, the shutter 74 blocks communication between the space S1 in the cylinder 71 and the interior of the chamber 2a. When closed, the shutter 74 is equipped with a seal member that prevents leakage of compressed air between the spaces S1 and S2. When open, the shutter 74 allows communication between the space in the chamber 2a and the space S1, allowing excavated soil taken into the chamber 2a to be drawn into the space S1.

[0063] The measuring device 120 further includes a pipe 75 that connects the space S1 in the cylinder 71 with the space in the container 22, an on-off valve 76 that is provided in the pipe 75 and that allows or blocks communication between the space S1 in the cylinder 71 and the space in the container 22, and a third pressure sensor 77 that detects the pressure in the space S1 in the cylinder 71. In this embodiment, the on-off valve 76 corresponds to the "valve device" in the claims, and the space S1 in the cylinder 71 corresponds to the "earth and sand storage space" in the claims. Furthermore, the third pressure sensor 77 corresponds to the "first pressure detector" in the claims.

[0064] The on-off valve 76 is driven to open and close by a drive device (not shown) based on instructions from the controller 40 .

[0065] The third pressure sensor 77 detects the pressure in the space S1 of the cylinder 71. Data on the pressure in the space S1 detected by the third pressure sensor 77 is transmitted to the controller 40.

[0066] A method for measuring the amount of air Vc present in the excavated soil in the chamber 2a using the measuring device 120 configured in this manner will be described with reference to the flowchart shown in Fig. 8. The processing shown in the flowchart in Fig. 8 is executed based on a program stored in advance in the controller 40.

[0067] In step S11, the pressure inside the container 22 is set to a predetermined value P2. Specifically, the controller 40 opens the on-off valve 27 while keeping the on-off valve 76 closed, and drives the compressor 25. As a result, compressed air is supplied into the container 22, and the pressure inside the container 22 increases.

[0068] When the controller 40 detects that the pressure inside the container 22 (the pressure detected by the second pressure sensor 24) has reached a predetermined value P2, it closes the on-off valve 27 to cut off communication between the compressor 25 and the container 22 and stops the compressor 25. If the pressure inside the container 22 has decreased during the lapse of a certain period of time (for example, several minutes) until the pressure inside the container 22 stabilizes, the on-off valve 27 is opened again and the compressor 25 is driven.

[0069] In step S12, the excavated earth is drawn into the space S1 of the cylinder 71. Specifically, the controller 40 opens the shutter 74 and drives the drive device 73 to move the piston 72 from the forward position to the backward position. This draws the excavated earth in the chamber 2a into the space S1 of the cylinder 71. When the piston 72 moves to the rear end position, that is, when the drawing of the excavated earth into the space S1 is completed, the controller 40 closes the shutter 74.

[0070] In step S13, the pressure in the space S1 of the cylinder 71 is detected. Specifically, the pressure in the space S1 is detected by the third pressure sensor 77. Data on the detected pressure is sent to the controller 40.

[0071] In step S14, the on-off valve 76 is opened. Specifically, the controller 40 drives the drive device to open the on-off valve 76, thereby connecting the space S1 with the container 22. This causes the compressed air in the container 22 to flow into the space S1, and over time, the pressure in the space S1 and the pressure in the container 22 become equilibrium.

[0072] In step S15, the amount of air Vc is calculated. Specifically, when it is determined that the pressure in the space S1 detected by the third pressure sensor 77 and the pressure in the container 22 detected by the second pressure sensor 24 have become equal, the controller 40 calculates the amount of air Vc contained in the excavated soil and sand in the chamber 2a.

[0073] Here, a method for calculating the air amount Vc in the second embodiment will be specifically described.

[0074] The ratio of soil, water, air, etc. contained in the excavated soil drawn into the space S1 of the cylinder 71 is the same as the ratio of the excavated soil in the chamber 2a. In other words, the excavated soil drawn into the space S1 of the cylinder 71 corresponds to a sample of the excavated soil in the chamber 2a.

[0075] Therefore, in this embodiment, the air volume Vs of the excavated soil in space S1 is measured, and the air volume Vc of the entire excavated soil in chamber 2a is calculated based on the ratio of this air volume Vs to the capacity of chamber 2a and the capacity of space S1.

[0076] When the on-off valve 76 is opened, the pressure in the space S1 increases due to the inflow of compressed air from the container 22. As explained in the first embodiment, even if the pressure in the space S1 changes, the volume of air contained in the excavated soil in the space S1 does not change.

[0077] Therefore, if the pressure when the pressure in space S1 and the pressure in container 22 are balanced is Pa1, the pressure in container 22 is Pb, the pressure in space S1 before opening valve device 23 is Ps, the capacity of container 22 is Vb, and the volume of air in space S1 is the air volume Vs, the following (Equation 2) is established.

[0078] Pa1×(Vb+Vs)= Pb×Vb+Ps×Vs (Formula 2) Here, the pressure Pa1, the pressure Pb, and the pressure Ps are measured values detected by the first pressure sensor 21 and the third pressure sensor 77, and the capacitance Vb is a known value.

[0079] The air volume Vs can be calculated by substituting the pressures Pa1, Pb, and Ps and the volume Vb into Equation 2. Then, the air volume Vc can be calculated by multiplying the air volume Vs by the ratio of the volume of the space S1 to the volume of the chamber 2a.

[0080] In this way, by using the measuring device 120 of this embodiment, as in the case of using the measuring device 20 of the first embodiment, the amount of air Vc present in the excavated soil in the chamber 2a can be accurately and quickly determined based on the change in pressure before and after opening the on-off valve 76.

[0081] The measuring device 120 according to the second embodiment described above has the following advantages in addition to the advantages of the measuring device 20 according to the first embodiment.

[0082] The measuring device 120 compares the pressure in the space S1 with the pressure in the container 22. The capacity of the space S1 is smaller than the capacity of the chamber 2a. Therefore, when the space S1 and the container 22 are connected to each other, the volume of compressed air required to increase the pressure in the space S1 is smaller than the volume of compressed air required to increase the overall pressure in the chamber 2a, as in the first embodiment. Therefore, in the measurement method using the measuring device 120, the pressure (predetermined value P2) of the compressed air supplied to the container 22 can be made lower than the pressure (predetermined value P1) in the measurement method using the measuring device 20 of the first embodiment. This allows for a reduction in energy consumption.

[0083] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0084] In the above embodiment, the shield machine 1 is used in the air bubble shield tunneling method, but the measuring devices 20, 120 can also be used in other tunneling methods.

[0085] In the above embodiment, the compressed air is stored in the container 22, but this is not limiting. For example, compressed air may be stored in a pressure-resistant hose instead of the container 22 or in addition to the container 22.

[0086] In the above embodiment, the amount of air Vc present in the excavated soil in the chamber 2a is calculated based on a program stored in the controller 40, but this is not limited to this, and some or all of the flowcharts shown in Figures 4 and 8 may be performed by an operator. [Explanation of symbols]

[0087] 1. Shield tunneling machine (excavation propulsion machine) 2a Chamber 4...Bulkhead 20. Measuring equipment 21 First pressure sensor (first pressure detector) 22... Container (air-filled space) 23 Valve gear 24 Second pressure sensor (second pressure detector) 25···Compressor 27. On-off valve 40... Controller 50···Filter 60 Check valve 70...Connection device 71 Cylinder 72 Piston (sliding member) 73...Drive unit, 74...Shutter 76...On-off valve (valve device) 77 Third pressure sensor (first pressure detector) 120...Measuring equipment, S1...space

Claims

1. A measuring device for measuring the amount of air present in excavated soil in a chamber of a shield tunneling machine, a first pressure detector for detecting the pressure of the soil storage space that stores the excavated soil; an air-filled space in which air at a predetermined pressure is sealed; a valve device that connects or blocks the soil storage space and the air sealing space; a second pressure detector for detecting the pressure in the air-filled space; A measuring device that balances the pressure in the soil storage space and the pressure in the air-filled space by opening the valve device.

2. The measurement device according to claim 1, The soil storage space is the chamber of the shield tunneling machine.

3. The measurement device according to claim 1, a connecting device for connecting the chamber and the air-filled space; The coupling device is a cylinder penetrating a partition wall that defines the chamber and opening into the chamber; a sliding member that slides along the inner wall of the cylinder; a drive device for driving the sliding member to draw excavated soil in the chamber into the cylinder; a shutter that connects or blocks communication between the cylinder and the chamber; The soil and sand storage space is a space partitioned by closing the shutter within the cylinder.

4. The measuring device according to claim 2 or 3, The measuring device further includes a compressor that supplies compressed air to the air-filled space.

5. The measuring device according to claim 2 or 3, The measuring device further comprises a filter for preventing excavated soil from flowing from the soil storage space into the air-filled space.

6. The measuring device according to claim 2 or 3, The measuring device further includes a check valve that prevents excavated soil from flowing from the soil storage space into the air-filled space.

7. A method for measuring the amount of air present in the excavated soil in the chamber using the measuring device according to claim 1, comprising: The soil storage space is the chamber of the shield tunneling machine, opening the valve device to allow the pressure in the chamber to equalize with the pressure in the air-filled space; and calculating the amount of air present in the excavated soil in the chamber based on the pressure in the chamber and the pressure in the air-sealed space before the valve device is opened, and the pressure when the pressure in the chamber and the pressure in the space are in equilibrium.

8. A method for measuring the amount of air present in the excavated soil in the chamber using the measuring device according to claim 1, comprising: the measuring device further includes a connecting device that connects the chamber and the air-filled space; The coupling device is a cylinder penetrating a partition wall that defines the chamber and opening into the chamber; a sliding member that slides along the inner wall of the cylinder; a drive device that drives the sliding member and draws the excavated soil taken into the chamber into the cylinder; a shutter that connects or blocks communication between the cylinder and the chamber; The soil storage space is a space defined by closing the shutter within the cylinder, a step of driving the sliding member by the driving device after opening the shutter to take the excavated soil in the chamber into the soil storage space; a step of closing the shutter and opening the valve device while the excavated soil has been taken into the soil storage space to balance the pressure in the soil storage space and the pressure in the air sealing space; and a step of calculating the amount of air present in the chamber based on the pressure in the soil storage space and the pressure in the air storage space before the valve device is opened, and the pressure when the pressure in the soil storage space and the pressure in the air storage space are in equilibrium.

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