Measurement system, measurement method, control device, and program

Abstract

A measurement system (10) according to the present disclosure comprises: a measuring instrument (11) that is disposed inside an underground structure (5) provided under a ground (4) and measures the number of muons that have passed through the ground (4); a measurement control unit (12) that controls the measurement by the measuring instrument (11); and an arithmetic unit (13) that calculates the density distribution of the ground (4) on the basis of the measurement result of the measuring instrument (11), wherein the measuring instrument (11) is provided with a moving mechanism (111) for moving inside the underground structure (5) under the control of the measurement control unit (12), and the measurement control unit (12) causes the measuring instrument (11) to measure the number of muons at each of a plurality of measurement points while moving the measuring instrument (11) in accordance with the cutting of the ground (4) by a shield machine (3).

Description

Measurement system, measurement method, control device and program

[0001] The present disclosure relates to a measurement system, a measurement method, a control device, and a program.

[0002] Land subsidence can cause severe damage to the surrounding social infrastructure, so it is necessary to measure the density distribution of the ground and detect and monitor underground cavities or loosening of the ground that can cause land subsidence.

[0003] Non-Patent Document 1 describes a technology for detecting underground cavities using a ground-based electromagnetic wave radar. This technology allows for the detection of underground cavities by emitting electromagnetic waves from a ground-based electromagnetic wave radar into the ground and detecting reflected waves from underground cavities or the like that have a different dielectric constant than the ground. Non-Patent Document 2 also describes a technology for measuring ground subsidence and displacement using positioning information from a synthetic aperture radar satellite. In this technology, microwaves are emitted from a synthetic aperture radar satellite toward the ground, and the intensity and phase of the waves reflected from the ground surface are observed. Multiple observations are made at the same location, and the difference in distance between the satellite and the ground surface is calculated based on the phase difference of the reflected waves, allowing for the detection of ground deformation.

[0004] Airec Giken, Road Esper 3D, [Retrieved June 7, 2023], Internet<URL:http: / / www.airec.co.jp / products / espar / RoadEspar3D.html> Geospatial Information Authority of Japan, Geospatial Information Authority of Japan Interferometric SAR, [Retrieved June 7, 2023], Internet<URL: https: / / www.gsi.go.jp / uchusokuchi / gsi_sar.html>

[0005] One of the causes of land subsidence is the excavation of the ground by shield machines. Therefore, there is a need for a technology that can measure the density distribution of the ground that is the target of excavation by shield machines while suppressing increases in costs.

[0006] With the technology described in Non-Patent Document 1, exploration becomes difficult as the ground depth increases because electromagnetic waves attenuate. Furthermore, with the technology described in Non-Patent Document 2, although it is possible to detect changes on the ground surface with high accuracy, it is not possible to detect changes in the ground unless they actually occur, making it difficult to detect changes in the ground before they occur.

[0007] Another possible method is to measure the density of the ground by drilling the ground and installing a measuring device. However, this method requires drilling more locations and installing a measuring device at each drilling location in order to measure the density of the ground over a wide area, which increases costs.

[0008] The purpose of the present disclosure, made in consideration of the above-mentioned problems, is to provide a measurement system, measurement method, control device, and program that can measure the density distribution of the ground to be cut by a shield machine while suppressing increases in costs.

[0009] In order to solve the above problems, the measurement system disclosed herein is a measurement system for measuring the density distribution of ground that is the target of cutting by a shield machine, and comprises: a measuring device that is placed inside an underground structure located under the ground and measures the number of muons that have passed through the ground; a measurement control unit that controls the measurement by the measuring device; and a calculation unit that calculates the density distribution of the ground based on the measurement results of the measuring device, wherein the measuring device is equipped with a movement mechanism for moving inside the underground structure under the control of the measurement control unit, and the measurement control unit moves the measuring device in accordance with the cutting of the ground by the shield machine, and causes the measuring device to measure the number of muons at each of a plurality of measurement points.

[0010] In order to solve the above problems, the measurement method disclosed herein is a measurement method for measuring the density distribution of ground that is the target of cutting by a shield machine, and includes the steps of measuring the number of muons that have passed through the ground using a measuring device placed inside an underground structure located under the ground, and calculating the density distribution of the ground based on the measurement results of the measuring device, wherein the measuring device is equipped with a movement mechanism for moving inside the underground structure, and the measuring device measures the number of muons at each of a plurality of measurement points while being moved in accordance with the cutting of the ground by the shield machine.

[0011] In order to solve the above problems, the control device of the present disclosure is a control device that is placed inside an underground structure located below the ground that is to be cut by a shield machine and controls a measuring device that measures the number of muons that have passed through the ground, and is equipped with a measurement control unit that controls the measurement by the measuring device and a calculation unit that calculates the density distribution of the ground based on the measurement results of the measuring device, and the measuring device is equipped with a moving mechanism for moving inside the underground structure under the control of the measurement control unit, and the measurement control unit moves the measuring device in accordance with the cutting of the ground by the shield machine, and causes the measuring device to measure the number of muons at each of a plurality of measurement points.

[0012] In order to solve the above problem, a program according to the present disclosure causes a computer to function as the above control device.

[0013] The measurement system, measurement method, control device, and program disclosed herein make it possible to measure the density distribution of the ground that is the target of cutting by a shield machine while suppressing increases in costs.

[0014] Fig. 1 is a diagram showing an example configuration of a measurement system according to an embodiment of the present disclosure. Fig. 2 is a diagram for explaining the arrangement of measuring instruments shown in Fig. 1. Fig. 3 is a diagram showing an example of an underground structure shown in Fig. 2. Fig. 4 is a diagram showing an example configuration of an open-cut tunnel shown in Fig. 3. Fig. 4 is a diagram showing an example configuration of a shield tunnel shown in Fig. 3. Fig. 5 is a diagram for explaining measurement by measuring instruments shown in Fig. 1. Fig. 6 is a flowchart showing an example of the operation of the measurement system shown in Fig. 1. Fig. 7 is a diagram showing an example configuration of a computer functioning as a control device shown in Fig. 1.

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0016] 1 is a diagram showing an example of the configuration of a measurement system 10 according to an embodiment of the present disclosure. The measurement system 10 according to this embodiment measures the density distribution of ground 4 to be cut by a shield machine 3, as shown in FIG.

[0017] 1 , a measurement system 10 according to this embodiment includes a measuring device 11, a measurement control unit 12, a calculation unit 13, and a data storage unit 14. The measurement control unit 12, the calculation unit 13, and the data storage unit 14 constitute a control device 15 that controls the measuring device 11. The control device 15 is installed, for example, on the ground, and is capable of communicating with the measuring device 11 via wired or wireless communication. Some or all of the components of the control device 15 may be provided integrally with the measuring device 11.

[0018] As shown in FIG. 2 , the measuring device 11 is disposed inside an underground structure 5 provided below the ground 4 to be excavated by a shield machine 3 that excavates the ground laterally from the side wall of a shaft 2. The underground structure 5 is, for example, an open-cut tunnel 5a provided in a position where the earth covering is relatively shallow (e.g., less than 10 m) or a shield tunnel provided in a position where the earth covering is relatively deep (e.g., 10 m or more), as shown in FIG. 3 . The open-cut tunnel 5a has a substantially rectangular shape when viewed from the front in the extension direction, as shown in FIG. 4A . The shield tunnel 5b has a substantially circular shape when viewed from the front in the extension direction, as shown in FIG. 4B . The diameter of the open-cut tunnel 5a and the shield tunnel 5b is, for example, about 2 m. The measuring device 11 is large enough to be disposed in such an underground structure 5.

[0019] As shown in Figure 2, the measuring device 11 measures the number of muons that have passed through the ground 4 to be cut. Muons are a type of secondary cosmic ray that is produced when cosmic rays collide with the Earth's atmosphere. Muons are less likely to be absorbed by the atmosphere than other cosmic rays and have a longer lifespan, allowing them to reach the Earth's surface. Muons also have the characteristic of being highly directional and penetrating, but are attenuated as they pass through the ground. Such configurations for measuring the number of muons are well known to those skilled in the art and are not directly related to the present invention, so a description thereof will be omitted.

[0020] Referring again to FIG. 1 , the measuring device 11 is equipped with a moving mechanism 111 for moving inside the underground structure 5 under the control of the measurement control unit 12, which will be described later. As described with reference to FIGS. 4A and 4B , the underground structure 5 in which the measuring device 11 is placed may have a variety of shapes. The moving mechanism 111 may have any configuration as long as it is capable of moving inside the underground structure 5 in which the measuring device 11 is placed. Note that the measuring device 11 may have a function for recording position information (e.g., the amount of movement). In this way, the position information of the measurement point can be recorded.

[0021] The measurement control unit 12 controls measurements by the measuring device 11 (measurement of the number of muons passing through the ground 4 to be cut). Specifically, the measurement control unit 12 moves the measuring device 11 as shown in FIG. 5 in accordance with the cutting of the ground 4 to be cut by the shield machine 3, and causes the measuring device 11 to measure the number of muons at each of multiple measurement points. For example, control data for the shield machine 3 cutting the ground 4 to be cut is input to the measurement control unit 12, and based on the control data, the measuring device 11 can move in accordance with the cutting of the ground 4 to be cut by the shield machine 3. FIG. 5 shows an example in which measurements are performed at three measurement points while the measuring device 11 is moved leftward. For example, the measurement control unit 12 moves the measuring device 11 so that it can measure the number of muons passing through the ground several meters ahead in the cutting direction from the cutting location by the shield machine 3.

[0022] Referring again to FIG. 1, the calculation unit 13 calculates the density distribution of the ground 4 to be cut based on the measurement results of the measuring device 11.

[0023] The rate at which muons penetrate the ground varies depending on the density of the ground and the thickness of the ground through which they penetrate, so by measuring the rate at which they penetrate, it is possible to calculate the average density multiplied by the vertical thickness (areal density). The relationship between areal density and the number of muons is known as Minato's empirical formula, and is expressed by the following formula (1).

[0024]

[0025] In formula (1), h is the surface density [hg / cm ２ ], θ is the zenith angle, and Iμ(h, θ) is the number of muons per unit time, unit area, and unit solid angle. Λ(h) and n are expressed by the following equations (2) and (3), respectively. Λ(h) = A + Bh + Ch ２ Formula (2) n=α+βh Formula (3) I ００ =0.00723[ / cm ２ / s / sr] A=17.61[cm ３ / hg]B=0.1404[cm ４ / hg ２ ] C=-7.06910－５ [cm ６ / hg ４ ] α=1.495 β=0.02018 [cm ２ / hg]

[0026] The calculation unit 13 inputs the number of muons measured by the measuring device 11 into Iμ(h, θ) in the formula (1), and also inputs θ, I ００ , Λ(h) and n, the surface density h is calculated. The calculation unit 13 outputs the calculated surface density h to the data storage unit 14 as the density distribution of the ground 4 to be cut.

[0027] As described above, muons have the characteristic of attenuating as they pass through the ground. Therefore, in ground without cavities or looseness (high-density ground), the degree of attenuation of muons is large, and the number of muons that reach the measuring device 11 is small. On the other hand, in ground with cavities or looseness (low-density ground), the degree of attenuation of muons is small, and the number of muons that reach the measuring device 11 is large. Taking advantage of this tendency, the calculation unit 13 can calculate the density distribution of the ground 4 to be cut using the measurement results of the measuring device 11.

[0028] The data storage unit 14 stores the measurement results of the density distribution of the ground 4 to be cut that are output from the calculation unit 13, and outputs them in response to operation input from the operator, for example.

[0029] Next, the operation of the measurement system 10 according to this embodiment will be described.

[0030] FIG. 6 is a flowchart showing an example of the operation of the measurement system 10 according to this embodiment, and is a diagram for explaining a measurement method using the measurement system 10.

[0031] As explained with reference to Figure 2, the measuring device 11 is placed inside the underground structure 5 provided below the ground 4 to be cut by the shield machine 3. The measuring device 11 placed inside the underground structure 5 provided below the ground 4 to be cut measures the number of muons that have passed through the ground 4 to be cut (step S11).

[0032] The calculation unit 13 calculates the density distribution of the ground to be cut based on the measurement results of the measuring device 11 (step S12). The calculation unit 13 calculates the density distribution, for example, by the above-mentioned formula (1).

[0033] Here, in the step of measuring the number of muons using the measuring device 11, the measurement control unit 12 moves the measuring device 11 in accordance with the cutting of the ground 4 to be cut by the shield machine 3, and causes the measuring device 11 to measure the number of muons at each of the multiple measurement points.

[0034] As described above, the measurement system 10 according to this embodiment includes a measuring device 11, a measurement control unit 12, and a calculation unit 13. The measuring device 11 is placed inside an underground structure 5 provided below the ground 4 to be cut by the shield machine 3, and measures the number of muons that have passed through the ground 4 to be cut. The measurement control unit 12 controls the measurement by the measuring device 11. The calculation unit 13 calculates the density distribution of the ground 4 to be cut based on the measurement results of the measuring device 11. The measuring device 11 includes a movement mechanism 111 for moving inside the underground structure under the control of the measurement control unit 12. The measurement control unit 12 moves the measuring device 11 in accordance with the cutting of the ground 4 to be cut by the shield machine 3, and causes the measuring device 11 to measure the number of muons at each of a plurality of measurement points.

[0035] By performing measurements at multiple measurement points while moving the measuring device 11, measurements can be made at multiple measurement points with a single measuring device 11, thereby suppressing increases in costs. Furthermore, by moving the measuring device 11 in accordance with the cutting by the shield machine 3, the density distribution of the ground 4 to be cut can be measured. Therefore, according to the present disclosure, the density distribution of the ground 4 to be cut by the shield machine 3 can be measured while suppressing increases in costs.

[0036] The above-described control device 15 can be realized, for example, by a computer 100 shown in FIG. 7 . A program for causing the computer 100 to function as the control device 15 may be provided. The program may be stored in a storage medium or provided via a network. FIG. 7 is a block diagram showing a schematic configuration of the computer 100 functioning as the control device 15. The computer 100 may be a general-purpose computer, a dedicated computer, a workstation, a PC (Personal Computer), an electronic notepad, or the like. The program instructions may be program code, code segments, or the like for executing necessary tasks.

[0037] 7, the computer 100 includes a processor 110, a read-only memory (ROM) 120, a random access memory (RAM) 130, a storage 140, an input unit 150, a display unit 160, and a communication interface (I / F) 170. Each component is communicably connected to one another via a bus 190. The processor 110 is specifically a central processing unit (CPU), a micro processing unit (MPU), a graphics processing unit (GPU), a digital signal processor (DSP), a system on a chip (SoC), or the like, and may be configured with multiple processors of the same type or different types.

[0038] The processor 110 is a control unit that controls each component and performs various arithmetic operations. That is, the processor 110 reads a program from the ROM 120 or the storage 140 and executes the program using the RAM 130 as a work area. The processor 110 controls each component and performs various arithmetic operations in accordance with the program stored in the ROM 120 or the storage 140. In this embodiment, the ROM 120 or the storage 140 stores a program for operating the computer 100 as the control device 15 according to the present disclosure. The program is read and executed by the processor 110 to realize each component of the control device 15 described above.

[0039] The program may be provided in a form stored on a non-transitory storage medium such as a CD-ROM (Compact Disk Read Only Memory), a DVD-ROM (Digital Versatile Disk Read Only Memory), a USB (Universal Serial Bus) memory, etc. The program may also be provided in a form downloaded from an external device via a network.

[0040] The ROM 120 stores various programs and various data. The RAM 130 temporarily stores programs or data as a working area. The storage 140 is configured with a hard disk drive (HDD) or a solid state drive (SSD) and stores various programs including the operating system and various data.

[0041] The input unit 150 includes a pointing device such as a mouse and a keyboard, and is used to input various types of information.

[0042] The display unit 160 is, for example, a liquid crystal display, and displays various types of information. The display unit 160 may employ a touch panel system and function as the input unit 150.

[0043] The communication interface 170 is an interface for communicating with other devices.

[0044] The following additional notes are provided regarding the above-described embodiments.

[0045] [Appendix 1] A measurement system for measuring the density distribution of ground that is the target of cutting by a shield machine, comprising: a measuring device that is placed inside an underground structure located under the ground and measures the number of muons that have passed through the ground; a measurement control unit that controls the measurement by the measuring device; and a calculation unit that calculates the density distribution of the ground based on the measurement results of the measuring device, wherein the measuring device has a movement mechanism for moving inside the underground structure under the control of the measurement control unit, and the measurement control unit moves the measuring device in accordance with the cutting of the ground by the shield machine, and causes the measuring device to measure the number of muons at each of a plurality of measurement points.

[0046] [Appendix 2] A measurement method for measuring the density distribution of ground that is the target of cutting by a shield machine, comprising: measuring the number of muons that have passed through the ground using a measuring device placed inside an underground structure located under the ground; calculating the density distribution of the ground based on the measurement results of the measuring device; the measuring device having a movement mechanism for moving inside the underground structure; and measuring the number of muons at each of a plurality of measurement points using the measuring device while moving in accordance with the cutting of the ground by the shield machine.

[0047] [Appendix 3] A control device that is placed inside an underground structure located under the ground that is to be cut by a shield machine and controls a measuring device that measures the number of muons that have passed through the ground, the control device comprising: a control unit; the control unit controls the measurements by the measuring device; and calculates the density distribution of the ground based on the measurement results of the measuring device; the measuring device comprises a movement mechanism for moving inside the underground structure in accordance with the control of the measurement control unit; and the control unit moves the measuring device in accordance with the cutting of the ground by the shield machine, while causing the measuring device to measure the number of muons at each of a plurality of measurement points.

[0048] [Supplementary Item 4] A non-transitory storage medium storing a program executable by a computer, the non-transitory storage medium storing the program causing the computer to operate as the control device according to Supplementary Item 3.

[0049] Although the above-described embodiments have been described as typical examples, it will be apparent to those skilled in the art that many modifications and substitutions can be made within the spirit and scope of the present disclosure. Therefore, the present invention should not be interpreted as being limited by the above-described embodiments, and various modifications and alterations are possible without departing from the scope of the claims. For example, multiple building blocks shown in the block diagrams of the embodiments can be combined into one, or one building block can be divided.

[0050] 2 Shaft 3 Shield machine 4 Ground to be cut 5 Underground structure 10 Measurement system 11 Measuring instrument 12 Measurement control unit 13 Calculation unit 14 Data storage unit 15 Control device 111 Moving mechanism

Claims

1. A measurement system for measuring the density distribution of ground that is the target of cutting by a shield machine, comprising: a measuring device that is placed inside an underground structure located under the ground and measures the number of muons that have passed through the ground; a measurement control unit that controls the measurement by the measuring device; and a calculation unit that calculates the density distribution of the ground based on the measurement results of the measuring device, wherein the measuring device has a movement mechanism for moving inside the underground structure under the control of the measurement control unit, and the measurement control unit moves the measuring device in accordance with the cutting of the ground by the shield machine, while causing the measuring device to measure the number of muons at each of a plurality of measurement points.

2. A measurement method for measuring the density distribution of ground that is the target of cutting by a shield machine, comprising the steps of: measuring the number of muons that have passed through the ground using a measuring device placed inside an underground structure provided under the ground; and calculating the density distribution of the ground based on the measurement results of the measuring device, wherein the measuring device has a moving mechanism for moving inside the underground structure, and the measuring device measures the number of muons at each of a plurality of measurement points using the measuring device while being moved in accordance with the cutting of the ground by the shield machine.

3. A control device that controls a measuring device that is placed inside an underground structure located under the ground that is to be cut by a shield machine and that measures the number of muons that have passed through the ground, comprising: a measurement control unit that controls the measurement by the measuring device; and a calculation unit that calculates the density distribution of the ground based on the measurement results of the measuring device, wherein the measuring device has a movement mechanism for moving inside the underground structure under the control of the measurement control unit, and the measurement control unit causes the measuring device to measure the number of muons at each of a plurality of measurement points while moving the measuring device in accordance with the cutting of the ground by the shield machine.

4. A program for causing a computer to function as the control device according to claim 3.