JP2022014396A - Natural ground measurement system, natural ground measurement method, natural ground control system and natural ground control method - Google Patents

Abstract

To provide a natural ground measurement system, a natural ground measurement method, a natural ground control system and a natural ground control method capable of feeding measurement data back to a subsequent mountain tunnel construction swiftly without restricting a collection timing of the measurement data or a measurement location.SOLUTION: A natural ground measurement system 50 for measuring quantitative data showing a natural ground property as a mountain tunnel 10 is drilled has a measurement instrument 20 stored in a measurement hole 16 extending from a pit wall 13 of the mountain tunnel 10 toward a natural ground G side, and a communication instrument 30 arranged at a pit mouth 12 side than the measurement hole 16. The measurement instrument 20 comprises a measurement part and a first communication part, and the first communication part comprises a LPWA radio communication module and a communication antenna for a radio transmission of measurement data measured by the measurement part to the communication instrument 30.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ground measurement system, a ground measurement method, a ground management system, and a ground management method.

In the construction of mountain tunnels, in order to grasp the properties (or state, behavior, etc.) of the ground, it is common to visually observe the face and to measure the deformation and stress state of the support members and the ground. In addition to the so-called A measurement, which is always carried out for daily construction management, there is the so-called B measurement, which is set in addition to the A measurement in consideration of the ground conditions. This B measurement includes underground displacement measurement, lining stress measurement, rock bolt axial force measurement, etc., all of which are installed with special measuring instruments to acquire quantitative data (measurement data) and the current ground. The properties of the ground are evaluated, and the properties of the future ground associated with excavation are evaluated.
For example, Patent Document 1 proposes a ground condition prediction method that enables highly accurate prediction of the ground condition in front of the face by accurately specifying the horizontal displacement in addition to the subsidence of the tunnel. ing. Specifically, in the tunnel arch portion of a tunnel having a cross-sectional shape including at least a semi-circular portion, a plurality of inclinometers are installed at intervals in the axial direction of the tunnel, measurement data of each inclinometer is acquired, and they are adjacent to each other. In a method of calculating the amount of change in the tilt angle from each measurement data of the inclinometer and predicting the ground condition in front of the face based on the calculation result, centering on the intersection of the horizontal spring line and the vertical center line. , The inclinometer is installed in the range of an angle of 55 degrees to 65 degrees from the spring line.

By the way, as a method of collecting measurement data measured by a measuring instrument in the construction of a mountain tunnel, a wired collection method of collecting data from the measuring instrument by a data logger or a PC (personal computer) via a wired cable is the mainstream. However, since it takes time to install and cure the wired cable in the tunnel, secure the power supply, etc., and the communication condition is not good in the mountain tunnel, the measurement data is collected by short-range wireless such as Bluetooth, short-distance. A wireless recovery method has been proposed.

Japanese Unexamined Patent Publication No. 2016-61080

Regardless of whether the above-mentioned wired collection method or short-range wireless collection method is applied, since it is necessary for workers and managers to access the vicinity of the measurement location, the data collection time zone (data collection timing) and measurement are required. There is a problem that both places (places where measuring instruments are installed) are often restricted. That is, since various vehicles and construction personnel come and go in the tunnel, the reason is that it is necessary to have a time zone and a measurement place that do not interfere with the construction.
Regarding the fact that the measurement location is limited, there is a concern that the skin may fall off the face when the measurement location is near the face, so a safe location away from the face surface to some extent should be used as the measurement location. Is also the reason. Regarding the ground measurement at a measurement location some distance from the face surface, considering that the measurement at a location close to the ground is suitable for the property evaluation in front of the ground, it may lead to a decrease in the property evaluation accuracy. .. In addition, since the time zone for data collection is limited, there may be a problem that it is difficult to promptly feed back the measurement data to the subsequent mountain tunnel construction.

The present invention is a ground measurement system, a ground measurement method, and a ground management that can promptly feed back the measurement data to the subsequent mountain tunnel construction without limiting the collection timing and the measurement location of the measurement data. The purpose is to provide a system and a method of managing the ground.

In order to achieve the above object, one aspect of the ground measurement system according to the present invention is
It is a ground measurement system that measures quantitative data showing the properties of the ground as the mountain tunnel is dug.
The measuring instrument and the measuring instrument housed in the measuring hole extending from the pit wall of the mountain tunnel to the ground side.
It has a communication device, which is arranged on the wellhead side of the measuring hole.
The measuring instrument includes a measuring unit and a first communication unit.
The first communication unit is characterized by including an LPWA wireless communication module and a communication antenna that wirelessly transmit measurement data measured by the measurement unit to the communication device.

According to this aspect, the measuring instrument housed in the measuring hole extending from the pit wall of the mountain tunnel to the ground side is equipped with the first communication unit, and the first communication unit is equipped with the LPWA wireless communication module, and the wellhead is more than the measuring hole. By transmitting measurement data (quantitative data) to a communication device arranged on the side, long-distance wireless communication in a mountain tunnel can be realized. This eliminates the restrictions on the collection timing and measurement location of the measurement data, and enables the measurement data to be promptly fed back to the subsequent mountain tunnel construction.
Here, LPWA (Low Power Wide Area) is a wireless communication method (for example, a communication method using an ISM (Industrial Scientific and Medical Band) of the 920 MHz band) that enables wide area data communication and low power consumption. Conventionally, there is no measurement system or measurement method that applies LPWA to mountain tunnels. Therefore, when LPWA is applied to a mountain tunnel, it is not clear whether long-distance communication is possible. Therefore, the present inventors transmit measurement data from the measuring instrument to the communication device by LPWA wireless communication in the mountain tunnel. We are verifying whether it is possible and demonstrating its applicability.
In the present specification, "long-distance communication" means, for example, wireless communication of measurement data at a distance of 1 km or more.

In this embodiment, the measuring instrument is housed in the measuring hole extending from the pit wall of the mountain tunnel to the ground side. Here, when the thickness of the sprayed concrete is thick (for example, 20 cm or more), a measuring hole can be created inside the sprayed concrete. Further, when the thickness of the sprayed concrete is, for example, about 5 cm to 10 cm, a measuring hole that penetrates the sprayed concrete and extends to the ground on the back surface thereof can be created.
Measuring instruments include inclinometers (for example, biaxial inclinometers), displacement meters, rock bolt axial force meters (stress meters), sprayed concrete stress meters, and the like. For example, when the measuring instrument is an inclinometer, the measuring unit can obtain measurement data regarding the inclination angle in the excavation direction (axial direction) and the cross-sectional direction (cross-sectional direction) of the mountain tunnel. The obtained measurement data is wirelessly communicated to a communication device on the wellhead side at a distance of, for example, 1 km or more via a communication antenna connected to the LPWA wireless communication module under the control of a control unit included in the measuring device.
The communication device that receives the measurement data is, for example, a user terminal (smartphone, tablet, personal computer, etc.) provided by a server device or a person involved in construction (construction manager, person in charge of the main branch of a construction company, a contractor, etc.) via a network. Will be sent to. By applying LPWA wireless communication, the number of communication devices installed in the tunnel can be reduced as much as possible, and depending on the length of the mountain tunnel, for example, only one communication device can be used as a measuring device. It becomes possible to transmit the measured measurement data to a server device or the like via a network.

Further, another aspect of the ground measurement system according to the present invention is characterized in that the entire measuring instrument is housed in the measuring hole.

According to this aspect, the entire measuring instrument is housed in the measuring hole, in other words, a part of the measuring instrument does not protrude from the mine wall into the mine, so that the measuring instrument is scattered at the time of blasting in mountain tunnel construction. It is possible to prevent the measuring instrument from being damaged by possible rock masses. The measuring instrument is equipped with a measuring unit and a first communication unit, and the first communication unit is equipped with an LPWA wireless communication module and a communication antenna. Among these components, the communication antenna is arranged most inside the tunnel. However, since the communication antenna is completely housed in the measurement hole, damage to the communication antenna is particularly prevented. It should be noted that, for example, there may be a measure to protect the communication antenna by projecting the communication antenna from the pit wall to the inside of the pit and providing a protective piece or the like for protecting the communication antenna in the vicinity of the measurement hole, but the protective piece is the tip of the communication antenna. It is hard to say that this is a preferable measure because the transmission of measurement data from the communication antenna to the communication device may be hindered by protecting the above.
Here, when the measuring instrument is completely housed inside the measuring hole, it may be a problem whether the measurement data can be satisfactorily transmitted from the communication antenna to the communication device, but when the measuring instrument is completely housed in the measuring hole. It has been demonstrated by the present inventors that long-distance communication is possible even in the above.

Further, another aspect of the ground measurement system according to the present invention is characterized in that the communication device is one of the following types.
(1) A gateway capable of transmitting and receiving the measurement data,
(2) A gateway capable of receiving the measurement data, an underground LAN connected to the gateway, and a transmission access point connected to the underground LAN.
According to this aspect, by having any one of the two types of communication devices, it is possible to satisfactorily transmit the measurement data to the server device and the user terminal provided by the person involved in the construction via the network. ..

Further, one aspect of the ground management system according to the present invention is
With the above-mentioned ground measurement system
A server device connected to the communication device via a network,
It has a user terminal, which is connected to the server device via a network, and has.
The server device includes a second communication unit that receives the measurement data and a storage unit that stores the measurement data.
The user terminal includes at least a third communication unit that receives the measurement data from the server device, and at least a display unit that displays the measurement data.
At least one of the server device and the user terminal is further provided with a determination unit for determining the ground property and / or the ground evaluation according to the ground property based on the measurement data. And.

According to this aspect, by transmitting measurement data by long-distance wireless communication in a mountain tunnel and transmitting measurement data from a communication device to a server device via a network, user terminals provided by a plurality of construction personnel can be provided. Measurement data can be shared simultaneously and in real time.
In addition, at least one of the server device and the user terminal evaluates the ground according to the ground properties and / or the ground properties (degree of hardness of the ground, stability / instability of the ground) based on the measurement data. , Appropriateness of the support pattern, etc.), for example, the suitability of the support pattern of the initial plan according to the current ground properties, the degree of hardness of the ground, etc. Can be identified promptly. If the current ground properties are worse (for example, softer) than the ground properties at the initial planning stage, it will be possible to quickly review the support pattern, and construction will be highly resistant to sudden changes in the ground properties. Construction management that guarantees safety can be realized.
In the judgment unit, the quality levels of a plurality of grounds (for example, hard, semi-hard, semi-soft, soft, etc.) are set according to the degree of hardness of the ground, and the support pattern according to each quality level is set. The pass / fail level is determined from the measurement data, and the support pattern according to the pass / fail level is determined.
By displaying the judgment result in the judgment unit on the display unit of the user terminal, for example, a plurality of construction-related persons can check the quality of the ground and the suitability of the support pattern of the current plan in real time at any time, and the support pattern when changed. Etc. can be specified.
Here, regarding the fact that at least one of the server device and the user terminal has a determination unit, if the determination unit is built in the server device, it is received via the second communication unit and stored in the storage unit. Based on the measurement data, the ground properties and the like are determined by the determination unit provided in the server device. Then, the determination result by the determination unit is transmitted to the user terminal in addition to the measurement data via the second communication unit of the server device.
On the other hand, when the determination unit is built in the user terminal (for example, the determination application software is downloaded to the user terminal to form the determination unit), it is transmitted from the second communication unit of the server device and the third communication is performed. Based on the measurement data received through the unit, the determination unit of the user terminal determines the ground properties and the like.

Further, one aspect of the ground measurement method according to the present invention is
It is a ground measurement method that measures quantitative data showing the properties of the ground as the mountain tunnel is dug.
A measurement hole construction process that constructs a measurement hole extending from the pit wall of the mountain tunnel to the ground side,
The first communication unit includes a measurement unit and a first communication unit, and the first communication unit includes a wireless communication module for wirelessly transmitting measurement data measured by the measurement unit to a communication device, and a communication antenna. , The measuring instrument installation process, which installs the entire measuring instrument in the measuring hole,
The communication device installation process, in which the communication device is installed on the wellhead side of the measurement hole,
It is characterized by having a measurement transmission step of measuring the quantitative data in the measurement unit and transmitting the measured measurement data to the communication device by LPWA radio.

According to this aspect, by having a measurement transmission process of transmitting measurement data from a measuring instrument to a communication device by LPWA radio, long-distance wireless communication in a mountain tunnel can be realized, and the collection timing of the measurement data can be determined. The measurement location is not restricted, and the measurement data can be quickly fed back to the subsequent mountain tunnel construction.
Further, in the measuring instrument installation process, by installing the entire measuring instrument in the measuring hole, it is possible to prevent the measuring instrument from being damaged by the rock mass that may be scattered when the construction of the mountain tunnel is blasted.

Further, one aspect of the ground management method according to the present invention is
Following the measurement transmission step in the ground measurement method, the measurement data is transmitted from the communication device to the server device via the network, and at least the measurement data is transmitted from the server device to the user terminal at the user terminal. It is a ground management method that identifies the ground properties of the mountain tunnel and manages the construction by displaying at least the measurement data.
At least one of the server device and the user terminal is characterized by having a determination step of determining the ground property and / or the ground evaluation according to the ground property based on the measurement data.
According to this aspect, in at least one of the server device and the user terminal, the ground property and / or the ground evaluation according to the ground property based on the measurement data (degree of hardness of the ground, stability of the ground). By having a judgment process for determining (property / instability, suitability of support pattern, etc.), for example, multiple user terminals have the suitability of the support pattern of the initial plan according to the current ground properties and the degree of hardness of the ground. Etc. can be specified promptly. Therefore, if the current ground properties are worse than the ground properties at the initial planning stage, it is possible to promptly review the support pattern, and high construction safety is achieved even for sudden changes in the ground properties. It is possible to realize guaranteed construction management.

According to the ground measurement system, the ground measurement method, the ground management system, and the ground management method of the present invention, the collection timing and the measurement location of the measurement data are not restricted, and the measurement data can be transferred to the subsequent mountain tunnel. You can quickly give feedback to the construction.

It is an overall block diagram which shows an example of the ground measurement system which concerns on embodiment. It is a figure which shows an example of the functional structure of the measuring instrument which constitutes a ground measurement system. Both (a) and (b) are diagrams showing an example of the functional configuration of the communication device. It is an overall block diagram which shows an example of the ground management system which concerns on embodiment. It is a figure which shows an example of the hardware configuration of a computer. (A) is a diagram showing an example of the functional configuration of the server device constituting the ground management system, and (b) is a diagram showing an example of the functional configuration of the user terminal constituting the ground management system. It is a flowchart which shows an example of the ground measurement method and the ground management method which concerns on embodiment. It is a diagram explaining the outline of the experiment for verifying the relationship between the communication distance of LPWA communication and the received signal strength in the mountain tunnel, (a) is the diagram explaining the outline of the straight line part, and (b) is the figure explaining the outline of the straight line part. It is a figure explaining the outline of a section. It is a graph which shows the experimental result about the relationship between the communication distance of LPWA communication, and the received signal strength. It is a figure explaining the outline of the experiment for verifying the relationship between the insertion depth of the measuring instrument accommodated in the measuring hole, and the received signal strength. It is a graph which shows the experimental result about the relationship between the insertion depth of a measuring instrument in a measuring hole, and the received signal strength.

Hereinafter, the easy-to-cut segment according to the embodiment will be described with reference to the attached drawings. In the present specification and the drawings, substantially the same components may be designated by the same reference numerals to omit duplicate explanations.

[Embodiment]
<Ground measurement system>
First, an example of the ground measurement system according to the embodiment will be described with reference to FIGS. 1 to 3. Here, FIG. 1 is an overall configuration diagram showing an example of a ground measurement system according to an embodiment, and FIG. 2 is a diagram showing an example of a functional configuration of a measuring instrument constituting the ground measurement system. Further, both FIGS. 3A and 3B are diagrams showing an example of the functional configuration of the communication device.

The tunnel to which the illustrated ground measurement system 50 is applied is a mountain tunnel in which the communication condition in the mine is generally poor. The mountain tunnel 10 is constructed by drilling a charging hole in the face 11 with an excavator such as a drill jumbo, charging with dynamite, and exploding. The mountain tunnel may be constructed by a tunnel boring machine (not shown).

After a predetermined extension is constructed by blasting or the like, steel arch support (support member 14) made of H-shaped steel or the like is installed at predetermined intervals in the excavation direction X to protect the tunnel wall. After that, the sprayed concrete 15 having a predetermined thickness (for example, about 5 cm to 25 cm) is constructed by spraying the concrete so as to involve the support member 14. The construction of the sprayed concrete 15 is carried out by bringing a concrete mixer truck into the mine and spraying the concrete with a spraying machine. After the concrete spraying is completed, lock bolts (not shown) are installed as needed. This lock bolt is made of a rod-shaped steel material having a length of, for example, about 3 m to 4 m, and causes the bolt to bear the tensile force caused by the deformation of the ground G toward the inside of the pit, thereby suppressing the deformation of the pit wall 13.

The ground measurement system 50 is a system that measures quantitative data showing the properties of the ground as the mountain tunnel 10 is dug. The ground measurement system 50 includes a measuring instrument 20 housed in a measuring hole 16 extending from the well wall 13 of the mountain tunnel 10 to the ground G side, and a communication device 30 arranged on the wellhead 12 side. Although one communication device 30 is shown in the vicinity of the wellhead 12 in FIG. 1, when the extension of the mountain tunnel 10 is extended over several km, for example, every 1 to 2 km from the face 11. A communication device 30 is installed, and for example, a plurality of measuring devices 20 and a plurality of communication devices 30 are used so that the measurement data measured by the measuring device 20 near the face can be transmitted to the communication device 30 near the wellhead. The measurement system 50 is configured. As will be described below, the communication device 30 on the wellhead side transmits the measurement data to the server device via the network, and the server device sends the measurement data and the measurement data to the user terminals provided by a plurality of construction personnel. Result data regarding the ground properties and the like determined based on the measurement data are transmitted and displayed on each user terminal.

In the illustrated example, the measuring hole 16A provided in the vicinity of the face at a distance t1 from the face 11 and the measuring hole 16B provided on the wellhead side of the measuring hole 16A are shown, and the measuring holes 16A and 16B are shown. Although the measuring instruments 20A and 20B are housed in the above, the measuring hole 16 is created at any time according to the excavation of the mountain tunnel 10, and the measuring instrument 20 is accommodated and installed, so that the excavation extension is long. As a result, the number of combinations of the measuring hole 16 and the measuring instrument 20 increases. Further, a plurality of measuring holes 16 are created in one cross section, and a measuring instrument 20 is often accommodated and installed in each measuring hole 16. For example, as described in Patent Document 1, the cross section is described. In the above, a plurality of measuring holes 16 are formed in a range of an angle of 55 degrees to 65 degrees from the spring line, and an inclinometer, which is a kind of measuring instrument 20, is housed and installed in each measuring hole 16.

As shown in FIG. 1, the measuring instrument 20 is installed in a state where the measuring instrument 20 is completely housed in the measuring hole 16, and the tip of the measuring instrument 20 on the pit wall side (for example, a communication antenna described below). The length t2 from to the pit wall 13 can be set to, for example, about several cm to 20 cm.

As shown in FIG. 2, the measuring instrument 20 has an outer tube 28 and a main tube 21 housed inside the outer tube 28. A pressing rod 29a projects from one end 28a of the outer tube 28, and a diameter-expanding fixed claw 29b that can be expanded or contracted is provided around the pressing rod 29a. The measuring instrument 20 is configured by inserting the main pipe 21 in the Y1 direction through the opening at the other end 28b of the outer pipe 28, and the outer pipe 28 is inserted into the measuring hole 16 with the enlarged diameter fixing claw 29b closed. By inserting and pressing the pressing rod 29a against the back wall of the measuring hole 16, the diameter-expanding fixing claw 29b is opened and the measuring instrument 20 is fixed inside the measuring hole 16. The measuring instrument 20 housed and installed inside the measuring hole 16 may be left as it is in the measuring hole 16, or in the measuring instrument 20 on the wellhead side where measurement is no longer necessary due to the excavation of the mountain tunnel 10, for example. The measuring instrument 20 may be removed from the measuring hole 16 by closing the enlarged diameter fixing claw 29b to release the fixed state, and the removed measuring instrument 20 may be diverted to another measuring hole 16 requiring measurement.

Since the entire measuring instrument 20 is housed in the measuring hole 16, in other words, a part of the communication antenna or the like of the measuring instrument 20 does not protrude into the mine from the mine wall 13, blasting or the like in the construction of the mountain tunnel 10 or the like. It is possible to prevent the measuring instrument 20 (for example, a communication antenna, etc.) from being damaged by the rock mass that can be scattered at the time.

The main 21 constituting the measuring instrument 20 includes a control unit 22, a storage unit 23, a measuring unit 24, and a first communication unit 25. The control unit 22 is mainly composed of a CPU (Central Processing Unit) (not shown), reads a predetermined program from a ROM (Read Only Memory) or the like constituting the storage unit 23, and similarly constitutes the storage unit 23. Various functions are realized by processing the program loaded in the RAM using (Random Access Memory) as the work area.

The measuring instrument 20 includes an inclinometer (for example, a biaxial inclinometer), a displacement meter, a rock bolt axial force meter, a sprayed concrete stress meter, and the like, but when the measuring instrument 20 is an inclinometer, measurement is performed. The unit 24 obtains measurement data (quantitative data) regarding the inclination angles of the mountain tunnel in the excavation direction (axial direction) and the cross-sectional direction (cross-sectional direction), and is stored in the storage unit 23. The format for storing (storing) the measurement data in the storage unit 23 is not particularly limited, and may be stored as log data or the like together with, for example, the measured time or the like.

The first communication unit 25 includes an LPWA wireless communication module 26 and a communication antenna 27. The LPWA wireless communication module 26 is a device that realizes LPWA wireless communication (wireless transmission), and is, for example, an electronic component in which a wireless chip and peripheral circuits are mounted on a small board.

The main communication methods (communication protocols) of LPWA include Sigfox, LoRaWAN (Long Range Wide Area Network), NB-IoT, etc., but for example, even in mountainous areas where the waves of mobile phone communication are difficult to reach without the need for a license. It is preferable to apply LoRaWAN, which can install a self-employed base station in the mine and can construct a low-cost communication system. LoRaWAN is a communication method that uses the ISM band of the 920 MHz band and employs LoRa modulation that enables long-distance communication even with a low output of 13 dBm or less.

The control unit 22 controls the communication device 30 so as not to repeatedly transmit the same measurement data. For example, the control unit 22 receives the receipt completion report data from the communication device 30 after executing the control to transmit the measurement data to the communication device 30, and does not retransmit the measurement data corresponding to the received receipt completion report data. In addition, processing such as setting a flag in the measurement data is executed.

The communication device 30 includes two forms shown in FIGS. 3 (a) and 3 (b). The communication device 30 of the form shown in FIG. 3A has a gateway 31 capable of receiving measurement data, an underground LAN (Local Area Network) 35 connected to the gateway 31, and a transmission connected to the underground LAN 35. It has a credit access point 36.

The gateway 31 has a control unit 32 and an LPWA wireless communication module 33, and has a communication antenna 34 that receives measurement data transmitted by LPWA radio from the measuring instrument 20 and the measurement data to a server device via a network. It further has a communication antenna 37 for transmission.

The underground LAN 35 includes a wired LAN control unit (not shown), and communication control by LAN is executed. Further, the transmission access point 36 is a device that realizes communication by various networks, and executes wireless communication using a wireless band of, for example, 2.4 GHz via a communication antenna 37.

On the other hand, the communication device 30A of the form shown in FIG. 3B is a communication device having only a gateway 31 capable of transmitting and receiving measurement data, and transmits measurement data to a server device and a communication antenna 34 for receiving measurement data. The communication antenna 37 and the communication antenna 37 are attached to the gateway 31. Since only the gateway 31 processes all transmission / reception of measurement data, the device configuration of the measuring instrument can be simplified as much as possible.

Returning to FIG. 1, according to the ground measurement system 50, the measurement data (quantitative data) is the LPWA wireless system from the measuring instrument 20 housed in the measuring hole 16 to the communication device 30 arranged on the wellhead 12 side. It is possible to realize long-distance wireless communication of 1 km or more in the mine of the mountain tunnel 10 by transmitting the data. This eliminates the restrictions on the collection timing and measurement location of the measurement data, and enables the measurement data to be promptly fed back to the subsequent mountain tunnel construction.

According to the verification experiment described below, it is specified that long-distance communication of about 1 km to 2 km is possible for transmission / reception of measurement data by the LPWA wireless method in the mine of the mountain tunnel 10. From the results of this verification experiment, in the ground measurement system 50, for example, a communication device 30 is installed every 1 km to 2 km from the measuring device 20 in the vicinity of the face, and the communication on the most well side connected to the external network is provided. It is desirable to be constructed as a system for transmitting measurement data to the device 30.

<Mountain management system>
Next, an example of the ground management system according to the embodiment will be described with reference to FIGS. 4 to 6. Here, FIG. 4 is an overall configuration diagram showing an example of the ground management system according to the embodiment. Further, FIG. 5 is a diagram showing an example of a computer hardware configuration, and FIGS. 6 (a) and 6 (b) are examples of functional configurations of a server device and a user terminal constituting a ground management system, respectively. It is a figure which shows.

The ground management system 100 is formed by connecting a communication device 30 on the wellhead side in a mountain tunnel 10 and a user terminal 80 provided by a plurality of construction personnel via a network 60. Examples of the user terminal 80 include a personal computer (PC), a tablet, and the like.

The user terminals 80 provided by a plurality of construction personnel are, for example, the user terminals 80A provided by the construction manager who constructs the mountain tunnel 10, and the user terminals provided at the construction work place (construction management building) at the construction site of the mountain tunnel 10. There are 80B, user terminal 80C provided by the person in charge of the main branch of the construction company, and other user terminals provided by various contractors and owners related to construction.

The network 60 includes a public network such as the Internet, a wireless network such as a mobile phone network, a dedicated network such as a VPN (Virtual Private Network), a LAN (Local Area Network), and the like. Here, the ground management system 100 has a form having a closed network in which information is shared only by one construction company, and a form having an open network in which information can be shared with various contractors and owners. Is.

Access to the server device 70 requires access authority, and only the user terminal to which the access authority is granted can access the server device 70 and share various data stored in the server device 70. Here, the server device 70 may be a cloud server in which various application software (applications) can be shared by a plurality of users in addition to data storage. For example, a determination application for determining a mountain property or the like based on the measurement data described below is stored in the server device 70, and a user terminal 80 having access authority accesses the server device 70 and stores it in the server device 70. By activating the judgment application based on the measured measurement data, it is possible to judge the ground properties and the like.

As shown in FIG. 5, the server device 70 includes an information processing device such as a personal computer or a workstation (WS: Work Station), and the user terminal 80 is also an information processing device, both of which are configured by the computer shown in FIG. Will be done.

A computer such as a server device 70 includes a CPU 71, a main storage device 72, an auxiliary storage device 73, a communication IF (interface) 74, and an input / output IF 75, which are connected to each other by a connection bus 76. The main storage device 72 and the auxiliary storage device 73 are computer-readable recording media. The above components may be provided individually, or some components may not be provided.

The CPU 71 is also called an MPU (Microprocessor) or a processor, and the CPU 71 may be a single processor or a multiprocessor. The CPU 71 is a central processing unit that controls the entire server device 70 and the like including a computer. The CPU 71, for example, expands the program stored in the auxiliary storage device 73 executably in the work area of the main storage device 72, and controls peripheral devices through the execution of the program, thereby performing a function that meets a predetermined purpose. I will provide a.

The main storage device 72 stores a computer program executed by the CPU 71, data processed by the CPU 71, and the like. The main storage device 72 includes, for example, a flash memory, RAM or ROM. The auxiliary storage device 73 stores various programs and various data in a readable / writable recording medium, and is also called an external storage device. The auxiliary storage device 73 stores, for example, an OS (Operating System), various programs, various tables, and the like. The OS includes, for example, a communication interface program that exchanges data with an external device or the like connected via the communication IF 74. The external device and the like include, for example, a personal computer (PC) connected to a network, a workstation (WS), a communication device 30 in a mountain tunnel 10, and the like.

The auxiliary storage device 73 is used, for example, as a storage area for assisting the main storage device 72, and stores a computer program executed by the CPU 71, data processed by the CPU 71, and the like. The auxiliary storage device 73 is a silicon disk including a non-volatile semiconductor memory (flash memory, EPROM (Erasable Programmable ROM)), a hard disk drive (HDD) device, a solid state drive device, or the like. Further, as the auxiliary storage device 73, a drive device for a detachable recording medium such as a CD drive device, a DVD drive device, and a BD drive device is exemplified, and as the detachable recording medium, a CD, a DVD, a BD, and a USB (Universal Serial Bus) are exemplified. ) Memory, SD (Secure Digital) memory card and the like are exemplified.

The communication IF 74 is an interface with the network 60 to which the server device 70 and the like are connected. The communication IF 74 receives measurement data from the communication device 30 in the mountain tunnel 10 via the network 60, and determines the measurement data and the ground properties determined based on the measurement data for each user terminal 80. Send the result data.

The input / output IF75 is an interface for inputting / outputting data to / from a device connected to the server device 70 or the like. For example, a keyboard, a pointing device such as a touch panel or a mouse, an input device such as a microphone, or the like is connected to the input / output IF75. The server device 70 or the like receives an operation instruction or the like from an operator who operates the input device via the input / output IF75.

Further, for example, a display device such as a liquid crystal panel (LCD: Liquid Crystal Display) or an organic EL panel (EL: Electroluminescence), and an output device such as a printer or a speaker are connected to the input / output IF75. For example, in the user terminal 80, the measurement data processed by the CPU 71 of the server device 70 and the determination result data related to the ground properties and the like are received via the communication IF 74 and displayed on the display device constituting the input / output IF 75. As a result, a plurality of construction personnel can visually check the measurement data and the like simultaneously and in real time.

As shown in FIG. 6A, the server device 70 provides at least various functions of the second communication unit 702, the determination unit 704, and the storage unit 706 by executing the program by the CPU 71. At least a part of the processing function may be provided by a DSP (Digital Signal Processor), a GPU (Graphics Processing Unit), or the like, and similarly, at least a part of the processing function is an FPGA (Field-Programmable Gate). It may be a dedicated LSI (large scale integration) such as an Array), a numerical arithmetic processor, an image processing processor, or other digital circuits.

The second communication unit 702 receives the measurement data transmitted from the communication device 30 installed in the mountain tunnel 10 via the network 60 and stores it in the storage unit 706.

The determination unit 704 is set with a plurality of ground quality levels (for example, hard, semi-hard, semi-soft, soft, etc.) according to the degree of hardness of the ground, and further corresponds to each quality level. A support pattern is set.

For example, by activating the determination unit 704, the determination unit 704 reads out the measurement data received by the second communication unit 702 and stored in the storage unit 706, and the plurality of measurement data (tilt angle data) read out. , Displacement data, etc.), a displacement mode in the cross section of the pit wall 13, a displacement mode in the vertical section, and the like are created, and the ground properties that bring about this displacement mode are evaluated. The quality level of the ground is judged based on the displacement mode and the maximum displacement amount.

The determination unit 704 specifies a support pattern set according to the pass / fail level for the ground for which the pass / fail level has been determined. For example, when it is determined that the ground is hard, a support pattern such as constructing an arch support made of H-shaped steel of specification △ at a pitch of ○ m is specified, and it is determined that the ground is soft. At that time, a support pattern is specified, such as installing lock bolts and installing arch support made of H-shaped steel of specification □ at ▽ m pitch.

The storage unit 706 stores the ground properties and support patterns in each construction section, which are set based on the geological survey and the like. The determination unit 704 determines, for example, the current ground properties (good or bad of the ground) based on the measurement data, and in addition to specifying the support pattern corresponding to the judgment result, the support pattern set at the planning stage. Is read from the storage unit 706, and it is also determined whether or not the planned support pattern is a support pattern suitable for the current ground conditions. In addition, the determination unit 704 further evaluates the ground properties in front of the face (the properties of the ground to be excavated in the future) based on the measurement data, and also provides a review of the support pattern at the planning stage as necessary. Will be done.

On the other hand, as shown in FIG. 6B, the user terminal 80 provides at least various functions of the third communication unit 802 and the display unit 804 by executing the program by the CPU 71. In the illustrated example, the server device 70 includes the determination unit 704, but the determination unit may be provided by downloading the determination application to each user terminal 80. Further, the user terminal 80 may also have a unique storage unit.

The third communication unit 802 receives the measurement data and the determination result data transmitted from the server device 70 via the network 60.

The display unit 804 displays the measurement data and the determination result data received by the third communication unit 802. The display contents on the display unit 804 include the measurement data of each measuring instrument 20, the ground properties and the displacement mode of the pit wall in the current construction section, the suitability of the support pattern in the current construction section, and the like.

By sharing the above-mentioned various information simultaneously and in real time on the unique user terminal 80, the construction personnel are safe in the support pattern at the planning stage for the current ground properties determined based on the measurement data. If there is concern about the nature, it will be possible to promptly review the support pattern with higher support strength. In addition, if the ground condition is better than in the planning stage, review the support pattern with lower support strength as necessary (for example, reduce the size of the support member by eliminating the need for rock bolt construction). By lengthening the placement pitch, etc.), it will lead to a reduction in construction costs.

<Ground measurement method and ground management method>
Next, an example of the ground measurement method and the ground management method according to the embodiment will be described with reference to FIG. 7. Here, FIG. 7 is a flowchart showing an example of the ground measurement method and the ground management method according to the embodiment.

The ground measurement method according to the embodiment includes each step from the measurement hole construction step (step S102) to the measurement transmission step (step S108) in the flowchart shown in FIG. Further, the ground management method according to the embodiment includes each step from the measurement hole construction step (step S102) to the support pattern evaluation step (step S114) in the flowchart shown in FIG. That is, the ground management method includes a ground measurement method.

In the ground measurement method, first, a measurement hole 16 is constructed in the mountain tunnel 10. The measuring holes 16 are constructed at any time according to the excavation of the tunnel, and a single or a plurality of measuring holes 16 are constructed in a cross section at a position separated from the face 11 by a predetermined distance (above, the measuring hole construction step (step S102)).

Next, the entire measuring instrument 20 (see FIG. 2) is installed in the measuring hole 16. By accommodating the entire measuring instrument 20 in the measuring hole 16, it is possible to prevent the measuring instrument 20 from being damaged by a rock mass that may be scattered during blasting or the like in the construction of the mountain tunnel 10. The measuring instrument 20 installed in the measuring hole 16 may be diverted to the measuring hole 16 separately constructed according to the excavation of the tunnel (the above is the measuring instrument installation step (step S104)).

At the same timing as the measuring instrument installation process, or at the timing before and after the measuring instrument, the communication device 30 is installed on the wellhead 12 side of the measuring hole 16 (for example, the measuring hole 16 near the face 11) where the measuring instrument 20 is installed. Install (communication device installation step (step S106)).

In the communication device installation process, one communication device 30 is installed near the wellhead 12 at the initial stage of tunnel construction (the stage of excavation length of about 1 km to 2 km where measurement data can be transmitted and received by LPWA radio). The ground measurement system 50 is constructed by the one communication device 30 and, for example, a plurality of measuring devices 20.

On the other hand, when the tunnel excavation length becomes a length that cannot be transmitted or received by LPWA radio, a communication device 30 is added at any time, and a ground measurement system 50 is constructed by a plurality of communication devices 30 and a plurality of measuring instruments 20. do. For example, in a long mountain tunnel 10, a measuring instrument 20 installed in the vicinity of the face 11 is provided, and a communication device 30 is installed in the mine at an interval of, for example, about 1.5 km from the measuring instrument 20. By going, it becomes possible to transmit the measurement data by the measuring instrument 20 in the vicinity of the face 11 to the communication device 30 installed closest to the wellhead 12, and the communication device 30 can send the server via the network 60. It becomes possible to transmit the measurement data to the device 70.

After constructing the ground measurement system 50 that can transmit the measurement data by LPWA radio to the communication device 30 installed on the most side of the wellhead 12 at each stage according to the excavation of the tunnel (after the communication device installation process). Quantitative data (measurement data) measured by the measurement unit 24 is transmitted to the communication device 30 by LPWA radio (measurement transmission step (step S108)).

As described above, according to the ground measurement method having each step from the measurement hole construction step (step S102) to the measurement transmission step (step S108), the LPWA radio is used even in the construction of a mountain tunnel where the communication condition in the mine is generally poor. The long-distance wireless communication by the above enables transmission and reception of measurement data with as few communication devices 30 as possible. Therefore, for example, it becomes possible to install a measuring instrument 20 in the vicinity of the face 11 to acquire measurement data, and it is possible to evaluate the ground properties with high accuracy, and both the time zone for data collection and the measurement location are restricted. Measurement data can be acquired at any time without having to.

Next, the measurement data is transmitted from the communication device 30 installed in the mine of the mountain tunnel 10 to the server device 70 via the network 60. The server device 70 makes evaluation judgments of various grounds such as the current ground properties and the degree of hardness of the grounds based on the measurement data. For example, the support pattern corresponding to the judgment result is specified and at the planning stage. Judgment is made as to whether or not the set support pattern is a support pattern suitable for the current ground conditions. It should be noted that this determination may be performed by the determination unit of each user terminal 80 based on the measurement data transmitted from the server device 70 (the above is the determination step (step S110)).

For example, the determination result data determined by the server device 70 is transmitted to each user terminal 80 together with the measurement data, and the received determination result data and the like are displayed on the display unit 804 of each user terminal 80. This display content includes the measurement data of each measuring instrument 20, the ground condition and the displacement mode of the pit wall in the current construction section, the measured maximum displacement amount and the allowable displacement amount, the suitability of the support pattern in the current construction section, etc. (The above is the display step (step S112)).

Construction personnel share the above-mentioned various information simultaneously and in real time on their own user terminal 80, and evaluate the suitability of the support pattern at the planning stage for the current ground properties determined based on the measurement data. , The support pattern is reviewed as necessary (support pattern evaluation step (step S114)).

As described above, according to the ground management method having each step from the measurement hole construction step (step S102) to the support pattern evaluation step (step S114), the planning stage for the current ground properties determined based on the measurement data. It is possible to promptly evaluate the suitability of the support pattern in the above, and to guarantee high construction safety by reviewing the support pattern with high support strength as necessary. In addition, by reviewing the support pattern with lower support strength as necessary, it will lead to reduction of construction cost.

[Verification experiment on the relationship between the communication distance of LPWA communication and the received signal strength]
The present inventors conducted a verification experiment on the relationship between the communication distance of LPWA communication in a mountain tunnel and the received signal strength, and specified the communicable distance in the mountain tunnel.

LoRAWAN in LPWA communication is known to be able to communicate at a distance of several kilometers to several tens of kilometers outdoors with good visibility, but the communication characteristics inside a mountain tunnel, which is a linear structure, are known. do not have. Therefore, in the construction of two mountain tunnels (here, the actual tunnel names are hidden, and the tentative names are A tunnel and B tunnel), underground communication using LoRaWAN standard communication equipment (LoRa wireless communication unit manufactured by PLNetworks). An experiment was conducted.

RSSI (Received Signal Strength Indication) was used to evaluate the communication status. RSSI is an index showing the strength of a received signal in wireless communication (unit: dBm), and its value decreases as the communication distance increases, and if it falls below a certain value, radio waves cannot be received. The minimum communicable RSSI of the communication device used in this experiment was about -134 dBm.

In this experiment, as shown in FIG. 8 (a), in addition to specifying the transmission / reception distance in the straight part of the mountain tunnel, as shown in FIG. 8 (b), the experiment was also performed on a junction with no line of sight. ..

The outline of each tunnel will be described. The tunnel A has a cross-sectional area of about 50 m ² and has an almost straight line with good visibility. On the other hand, the B tunnel has a small cross section (about 35 m ² ) and has a part with a large curvature, which is disadvantageous as a communication environment as compared with the A tunnel.

Regarding the pit wall inside the mine, most of the pit walls in the experimental section were covered with lining concrete in the A tunnel, but in the B tunnel, the sprayed concrete and steel support were exposed on the entire line. there were. In addition, belt conveyors for sliding out were installed in both tunnels.

The experimental results are shown in FIG. In FIG. 9, the estimation formula of the propagation loss of the following equation (1) derived from the Fris transfer formula is shown by a dotted line, a one-dot chain line, and a two-dot chain line.

From FIG. 9, it was found that RSSI decreases as the communication distance increases in both tunnels. Specifically, it was confirmed that in the A tunnel, communication was possible up to a distance of 1.7 km between the transmitter and receiver, but since the face was reached, verification at a distance longer than that was not possible.

On the other hand, it was confirmed that the B tunnel with poor visibility can communicate up to 1.4 km. In the B tunnel, we tried to communicate at another 1.6km point, but could not receive the radio waves.

As shown in FIG. 9, when the graph based on the propagation loss estimation formula derived from the Fris transmission formula is superimposed on the experimental results of both tunnels, the inside of the mountain tunnel is approximately n = 2.5 to 3. It can be seen that the conditions between 0 are met.

On the other hand, as a result of communication on the junction shown in FIG. 8 (b), RSSI was −120 dBm. This is an RSSI corresponding to a communication distance of 1.5 km in the straight line portion, and it was found that the radio wave is greatly attenuated when the line of sight is not clear. However, it has been demonstrated that communication is possible even under completely unclear conditions.

From this experiment, it has been demonstrated that when LPWA wireless communication is applied in a mountain tunnel, long-distance wireless communication of about 1.5 km is possible.

[Verification experiment on the relationship between the insertion depth of the measuring instrument in the measuring hole and the received signal strength]
The present inventors further conducted a verification experiment on the relationship between the insertion depth of the measuring instrument in the measuring hole and the received signal strength, and verified the possibility of transmitting and receiving the measured data when the measuring instrument was completely housed in the measuring hole.

In this experiment, as shown in FIG. 10, the measuring instrument is inserted into the measuring hole of φ50 mm provided at the top end, and the receiver for receiving the measurement data is installed in the mine about 10 m away from the measuring hole, and the insertion depth is set. Investigated the effect of

The experimental results are shown in FIG. From FIG. 11, it was found that RSSI decreased in proportion to the insertion depth of the measuring instrument. When incorporating the LoRa communication module (LPWA communication module) and the communication antenna into the measuring instrument, the insertion depth is assumed to be 10 cm or less. From this and the results of this experiment, it can be seen that the effect of the surrounding sprayed concrete on communication is limited to a reduction of RSSI of about a dozen dBm.

From this experiment, it has been demonstrated that LPWA wireless communication can be applied in a mountain tunnel, and measurement data can be wirelessly communicated over a long distance even when the entire measuring instrument is completely housed in the measuring hole.

It should be noted that the configuration or the like described in the above embodiment may be another embodiment in which other components are combined, and the present invention is not limited to the configuration shown here. This point can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form thereof.

10: Mountain tunnel 11: Face 12: Wellhead 13: Well wall 14: Support member 15: Sprayed concrete 16, 16A, 16B: Measuring hole 20, 20A, 20B: Measuring instrument 21: Main 22: Control unit 23: Storage Unit 24: Measurement unit 25: First communication unit 26: LPWA wireless communication module 27: Communication antenna 28: Outer tube 30, 30A: Communication device 31: Gateway 32: Control unit 33: LPWA wireless communication module 34, 37, 38: Communication antenna 35: LAN cable 36: Access point for transmission 50: Ground measurement system 60: Network 70: Server device 80, 80A, 80B, 80C: User terminal 100: Ground management system 702: Second communication unit 704: Judgment Part 706: Storage part 802: Third communication part 804: Display part G: Ground

Claims (6)

It is a ground measurement system that measures quantitative data showing the properties of the ground as the mountain tunnel is dug.
The measuring instrument and the measuring instrument housed in the measuring hole extending from the pit wall of the mountain tunnel to the ground side.
It has a communication device, which is arranged on the wellhead side of the measuring hole.
The measuring instrument includes a measuring unit and a first communication unit.
The first communication unit is characterized by including an LPWA wireless communication module and a communication antenna that wirelessly transmits measurement data measured by the measurement unit to the communication device. .. The ground measurement system according to claim 1, wherein the entire measuring instrument is housed in the measuring hole. The ground measurement system according to claim 1 or 2, wherein the communication device is any one of the following.
(1) A gateway capable of transmitting and receiving the measurement data,
(2) A gateway capable of receiving the measurement data, an underground LAN connected to the gateway, and a transmission access point connected to the underground LAN. The ground measurement system according to any one of claims 1 to 3 and the ground measurement system.
A server device connected to the communication device via a network,
It has a user terminal, which is connected to the server device via a network, and has.
The server device includes a second communication unit that receives the measurement data and a storage unit that stores the measurement data.
The user terminal includes at least a third communication unit that receives the measurement data from the server device, and at least a display unit that displays the measurement data.
At least one of the server device and the user terminal is further provided with a determination unit for determining the ground property and / or the ground evaluation according to the ground property based on the measurement data. The ground management system. It is a ground measurement method that measures quantitative data showing the properties of the ground as the mountain tunnel is dug.
A measurement hole construction process that constructs a measurement hole extending from the pit wall of the mountain tunnel to the ground side,
The first communication unit includes a measurement unit and a first communication unit, and the first communication unit includes a wireless communication module for wirelessly transmitting measurement data measured by the measurement unit to a communication device, and a communication antenna. , The measuring instrument installation process, which installs the entire measuring instrument in the measuring hole,
The communication device installation process, in which the communication device is installed on the wellhead side of the measurement hole,
A ground measurement method comprising: a measurement transmission step of measuring the quantitative data by the measurement unit and transmitting the measured measurement data to the communication device by LPWA radio. Following the measurement transmission step in the ground measurement method according to claim 5, the measurement data is transmitted from the communication device to the server device via a network, and at least the measurement data is transmitted from the server device to the user terminal. It is a ground management method that identifies the ground properties of the mountain tunnel and manages the construction by displaying at least the measurement data on the user terminal.
At least one of the server device and the user terminal is characterized by having a determination step of determining the ground property and / or the ground evaluation according to the ground property based on the measurement data. Ground management method.

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