Working face monitoring system and working face monitoring method

Abstract

To provide a working face monitoring system and a working face monitoring method for easily moving a vibration visualization radar.SOLUTION: A working face monitoring system for monitoring a working face in tunnel excavation construction comprises: one vibration visualization radar that transmits a monitoring wave to the working face and receives a reflected wave of the monitoring wave; and a detector that detects a change of the working face on the basis of a reception signal from the vibration visualization radar. The vibration visualization radar is fixed to a portion near the levee crown.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a face monitoring system and a face monitoring method. [Background technology]

[0002] The following Patent Document 1 discloses a tunnel face safety monitoring system and method (background technology). This background technology is composed of a vibration visualization radar that is mainly placed inside the tunnel to measure the displacement and vibration of the tunnel face, and a measurement control PC that is also placed inside the tunnel to process signals from the measurement data, calculate evaluation indexes for predicting face collapse, and create display images of the measurement results, etc., and by simultaneously measuring minute displacements of the tunnel face and changes in vibration characteristics in real time, it is possible to detect signs of loosening and collapse of the ground during tunnel face work in advance.

[0003] More specifically, in the background art, when measuring the displacement behavior of the tunnel face inside the tunnel, the vibration visualization radar is placed near the left and right side walls about 10 to 20 m away from the tunnel face, and the measurement control PC is placed about 10 m behind the vibration visualization radar. The excavation work at the tunnel face includes a process in which a construction machine such as a drill jumbo approaches the face and performs work such as drilling. In this case, the radio waves emitted from the vibration visualization radar may hit the construction machine, resulting in some areas where the reflected waves from the tunnel face are not observed. To avoid this, radio waves are emitted toward the tunnel face from both the left and right sides, not just one side of the tunnel side wall.

[0004] That is, in the background art, even if the radio waves emitted from one vibration visualization radar are blocked by a construction machine or the like and cannot reach the tunnel face in some areas, the radio waves emitted from the other vibration visualization radar can reach that area and the reflected waves can be observed. By arranging the vibration visualization radars in this way, the areas where the reflected waves from the tunnel face are not observed are minimized. In the background art, an installation frame is fixed to steel support constructed at a position a predetermined distance behind the tunnel face, and the vibration visualization radar is attached to this installation frame. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7157414 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above-mentioned background art has the following problems. That is, when the distance between the vibration visualization radar and the face exceeds the measurement range (about 10 to 20 m) as the face advances due to tunnel excavation, the vibration visualization radar needs to be moved to the face side. In that case, a series of tasks is required, such as removing the two vibration visualization radars from their installation stands, reattaching the installation stands to the forward support, and re-installing the vibration visualization radar on the moved installation stands, which requires time and effort.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a face monitoring system and a face monitoring method in which the vibration visualization radar can be easily moved. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the present invention adopts, as a first solution relating to a face monitoring system, a means in which a face monitoring system for monitoring a face during tunnel excavation work is provided with a vibration visualization radar that transmits monitoring waves to the face and receives reflected waves of the monitoring waves, and a detection device that detects changes in the face based on the received signal of the vibration visualization radar, and the vibration visualization radar is fixed to a location near the top of the tunnel.

[0009] In the present invention, as a second solution related to the face monitoring system, a solution is adopted in which, in the above-mentioned first solution, the vibration visualization radar is fixed to a steel support constructed in the tunnel via an angle iron.

[0010] The present invention employs, as a third solution related to a face monitoring system, a solution in which, in the above-mentioned first or second solution, the arrangement direction of the receiving antennas of the vibration visualization radar is vertical.

[0011] In the present invention, as a solution relating to a face monitoring method, a face monitoring system for monitoring a face during tunnel excavation work is adopted, which has a first step of transmitting monitoring waves from a vibration visualization radar to the face and receiving the reflected waves of the monitoring waves by the vibration visualization radar, and a second step of detecting changes in the face based on the received signal of the radar, and the vibration visualization radar is fixed to a location near the top of the tunnel. Effect of the Invention

[0012] According to the present invention, it is possible to provide a face monitoring system and a face monitoring method that allow the vibration visualization radar to be easily moved and protected. [Brief description of the drawings]

[0013] [Figure 1] 1A is a schematic diagram showing the overall configuration of a face monitoring system according to one embodiment of the present invention, and FIG. 1B is a schematic diagram showing the installation state of a vibration visualization radar. [Diagram 2] FIG. 2 is an enlarged view showing a detailed installation state of the vibration visualization radar in one embodiment of the present invention. [Diagram 3] 1A is a schematic diagram showing the arrangement of receiving antennas in one embodiment of the present invention, and FIG. 1B is a schematic diagram showing a radar coordinate system. [Figure 4] 1A is a schematic diagram showing a face coordinate system in one embodiment of the present invention, and FIG. 1B is a schematic diagram showing pixels on the face. [Diagram 5] FIG. 2A is a schematic diagram showing a case where a vibration visualization radar in one embodiment of the present invention is installed on the left wall side of a tunnel, and FIG. 2B is a schematic diagram showing pixel division on the face of a tunnel. [Figure 6]In one embodiment of the present invention, (a) is a schematic diagram showing a vibration visualization radar using a horizontally arranged receiving antenna installed near the roof of a tunnel, and (b) is a schematic diagram showing pixel division on the face of a tunnel. [Figure 7] In one embodiment of the present invention, (a) is a schematic diagram showing a vibration visualization radar using a receiving antenna rotated by 90 degrees installed near the roof of a tunnel, and (b) is a schematic diagram showing pixel division on the face of a tunnel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a case will be described in which tunnel excavation work is carried out using the New Austrian Tunneling Method (NATM), which is well known as a standard excavation method for mountain tunnels.

[0015] In NATM, after blasting and machinery are used to excavate a tunnel, steel supports (e.g. H-beams) are constructed in a rib-like shape on the excavated surface. In NATM, concrete is sprayed onto the excavated surface to bury the steel supports, and then rock bolts are driven into the ground from inside the tunnel. Furthermore, in NATM, waterproof sheets are installed inside the tunnel, and forms are constructed to cover the tunnel with concrete.

[0016] First, the overall configuration of a tunnel face monitoring system A according to this embodiment will be described with reference to Fig. 1. As shown in Fig. 1(a), the tunnel face monitoring system A comprises a vibration visualization radar 1 and a computer 2 installed in a tunnel T being excavated. This tunnel face monitoring system A is a monitoring device that monitors a tunnel face W, which is the tip of the tunnel T being excavated, and is a small, lightweight box-shaped device with dimensions of, for example, about 30 cm wide x 20 cm high x 25 cm deep.

[0017] The vibration visualization radar 1 is a single radar fixed to a steel support S, as shown in Fig. 1(b). This vibration visualization radar 1 transmits (irradiates) radio waves of a predetermined frequency in a two-dimensional scanning manner as monitoring waves to substantially the entire area of ​​the face W across a two-dimensional range, and receives reflected waves of the monitoring waves at the face W. The monitoring waves in this embodiment are, for example, millimeter waves.

[0018] That is, this vibration visualization radar 1 irradiates a beam-shaped surveillance wave with sharp directionality to the face W. Moreover, this vibration visualization radar 1 two-dimensionally scans the irradiation position of the surveillance wave (beam wave) at the face W, thereby irradiating the surveillance wave (beam wave) to substantially the entire area of ​​the face W and receiving the reflected wave at the irradiation position of the surveillance wave (beam wave).

[0019] Such a vibration visualization radar 1 is equipped with multiple receiving antennas 1a (see FIG. 3) arranged one-dimensionally, and simultaneously receives reflected waves (scattered waves) generated by the reflection of the monitoring waves at the tunnel face W with the multiple receiving antennas 1a. The vibration visualization radar 1 outputs the received signals of each receiving antenna 1a to the computer 2. These received signals are signals that indicate the amount of displacement at the irradiation position of the monitoring waves at the tunnel face W, i.e., the reflection position of the reflected waves.

[0020] The steel supports S are steel structures constructed in a rib-like shape on the excavation face H of the tunnel T, i.e., on the side of the tunnel T, and are constructed at predetermined intervals from the entrance of the tunnel T to the face W. In other words, the steel supports S are provided at predetermined intervals in the excavation direction of the tunnel T and have sufficient mechanical strength.

[0021] The computer 2 is, for example, a personal computer (PC), and is electrically connected to the vibration visualization radar 1. This computer 2 performs synthesis processing in real time on a plurality of received signals in the vibration visualization radar 1 based on a face monitoring program (application program) pre-installed therein, thereby detecting changes (amount of displacement) in the monitored object two-dimensionally and at high speed. The computer 2 corresponds to the detection device in the present invention.

[0022] When this computer 2 detects a significant change in the tunnel face W, it transmits a warning signal to a warning notification device separately installed in the tunnel T or to a mobile device such as a smartphone carried by a worker. The warning notification device, for example, in the case of a warning light, notifies the worker to move away from the tunnel face W by flashing a red light along with a sound indicating evacuation. The mobile device also notifies the worker to move away from the tunnel face W by sounding a sound or alarm indicating evacuation using an installed warning application.

[0023] Furthermore, computer 2 transmits warning signals via a wireless router to terminals such as personal computers and warning notification devices such as warning lights installed in the management center of the site office or field station. Transmission and reception between computer 2 and the warning notification devices, and between the terminals and warning notification devices, may be wireless or wired. Also, danger signals and images showing the state of the face in the face coordinate system may be transmitted via an internet line or the like to terminals in departments related to excavation work other than the work site where tunnel T is excavated.

[0024] Next, the detailed installation state of the vibration visualization radar 1 will be described with reference to Fig. 2. The vibration visualization radar 1 is fixed to the steel support S as shown in Fig. 1(b), but the fixing position in the circumferential direction of the tunnel T is a part near the top end of the tunnel T as shown in Fig. 2(a). In other words, the fixing position of the vibration visualization radar 1 is set within a range of 1 to 2 m (meters) from the top end of the tunnel T, for example.

[0025] As shown in Fig. 2(a) and Fig. 2(b), the vibration visualization radar 1 is fixed to a steel support S via an installation base 3 and a camera platform 4. The installation base 3 is formed in a U-shape and includes a plurality of frame members, namely, two vertical frames 3a and 3b and one lower frame 3c (horizontal frame).

[0026] Of the two vertical frames 3a, 3b, one vertical frame 3a is a rod-shaped angle material in a vertical position, with its upper end connected to the lower end of the steel support S and its lower end connected to one end of the lower frame 3c. The other vertical frame 3b is a rod-shaped angle material in a vertical position facing the one vertical frame 3a in parallel with a specified distance. The other vertical frame 3b has its upper end connected to the lower end of the steel support S and its lower end connected to the other end of the lower frame 3c.

[0027] The lower frame 3c is a rod-shaped angle member in a horizontal position, with one end connected to the lower end of one vertical frame 3a and the other end connected to the lower end of the other vertical frame 3ba. A camera platform 4 is installed in approximately the center of the lower frame 3c in the longitudinal direction (horizontal direction).

[0028] As shown in the figure, the pan head 4 is provided between the lower frame 3c and the lower part of the vibration visualization radar 1. This pan head 4 is a relay member for mounting the vibration visualization radar 1 on the installation frame 3, and sets the direction of the vibration visualization radar 1, that is, the irradiation direction of the surveillance wave at the face W.

[0029] Next, the arrangement of the multiple receiving antennas 1a in the vibration visualization radar 1 will be described with reference to Fig. 3. In the vibration visualization radar 1, the arrangement direction of the multiple receiving antennas 1a is vertical. That is, the receiving antennas 1a are positioned perpendicular to the transmitting antennas 1b as shown in Fig. 3(a).

[0030] Fig. 3(b) shows a monitoring coordinate system (radar coordinate system) of the vibration visualization radar 1 in this embodiment. This radar coordinate system is a polar coordinate system consisting of a cross-range direction (vertical direction) corresponding to the arrangement direction of the receiving antennas 1a and a range direction (horizontal direction) corresponding to the direction perpendicular to the arrangement direction of the receiving antennas 1a. Note that Fig. 3(c) shows the arrangement of receiving antennas in a general radar. In a general radar, the receiving antenna is arranged to the side of the transmitting antenna, that is, next to the transmitting antenna in the horizontal direction, as shown in this figure.

[0031] Next, the operation of the face monitoring system A according to this embodiment, that is, a face monitoring method using the face monitoring system A, will be described in detail with reference to Figs.

[0032] In this face monitoring system A, a monitoring wave is transmitted from the vibration visualization radar 1 to the face W, and the reflected wave of the monitoring wave at the face W is received by the vibration visualization radar 1 (first step). In the face monitoring method according to this embodiment, a received signal is acquired by this first step. This received signal is a signal that indicates the amount of displacement at each coordinate of the surface (face surface) of the face W in the radar coordinate system (polarized coordinate system) shown in Fig. 3(b).

[0033] The computer 2 converts the displacement amount of each coordinate in the radar coordinate system into the displacement amount of each coordinate in the face coordinate system (XYZ Cartesian coordinate system) shown in Fig. 4. Then, the computer 2 acquires the displacement amount of each pixel divided into a grid pattern in the face coordinate system, i.e., the face, as shown in Fig. 4(b). That is, the computer 2 detects the change in the face W, i.e., the displacement amount of the face, based on the received signals sequentially input from the vibration visualization radar 1 (second step).

[0034] The pixel division of the face in this second process is set according to the spatial resolution of the vibration visualization radar 1. The shape of the grid division can be any shape depending on the positional relationship between the installation position of the vibration visualization radar 1 and the face. The installation position of the vibration visualization radar 1 is the origin O in the face coordinate system (XYZ Cartesian coordinate system) as shown in Fig. 4(b).

[0035] Here, Fig. 5(a) shows the above-mentioned general radar installed at the bottom of the left wall side of tunnel T. In this case, the observation arrangement is from the lower left looking up to the upper right, so the pixel division at the face is coarse in the lower left part and becomes finer toward the upper right, as shown in Fig. 5(b).

[0036] Next, Fig. 6(a) shows the above-mentioned general radar installed near the top of tunnel T. In this case, the pixel division at the face is an observation arrangement looking down from the upper left to the lower right, so the pixel division is coarse in the upper left part and becomes finer toward the bottom, as shown in Fig. 6(b).

[0037] 7(a) shows a case where the vibration visualization radar 1 according to this embodiment is used, that is, a state where the vibration visualization radar 1 with receiving antennas aligned vertically is installed near the top of a tunnel T. In this case, the observation arrangement looks down from the upper left to the lower right, but since the receiving antennas 1a are aligned vertically, the pixel widths in the vertical direction are uniform and the pixel widths become smaller toward the right. As a result, the vertical width of the upper pixels is smaller than when the above-mentioned general radar is used, and the decrease in spatial resolution near the top is suppressed.

[0038] According to this embodiment, the face monitoring system A, which monitors the face W during tunnel excavation work, is equipped with a vibration visualization radar 1 that transmits monitoring waves to the face W and receives reflected waves of the monitoring waves, and a computer 2 (detection device) that detects changes in the face W based on the received signal of the vibration visualization radar 1, and since the vibration visualization radar 1 is fixed to a location near the top of the tunnel T, the effort and time required to move the vibration visualization radar 1 can be reduced.

[0039] That is, while in the background art it is necessary to move two vibration visualization radars, in the tunnel face monitoring system A according to this embodiment, the vibration visualization radar 1 is fixed to a location near the top of the tunnel T, so it is possible to detect changes in the tunnel face W by using a single vibration visualization radar 1. Therefore, according to this embodiment, it is possible to provide a tunnel face monitoring system A and a tunnel face monitoring method in which the vibration visualization radar 1 can be easily moved.

[0040] Furthermore, according to this embodiment, since the vibration visualization radar 1 is installed near the top end, it is possible to keep it away from the working range of construction machinery, transport machinery, etc. used in tunnel excavation work, and it is possible to prevent damage to the vibration visualization radar 1 due to contact with the construction machinery, transport machinery, etc.

[0041] Furthermore, according to this embodiment, since only one vibration visualization radar 1 is used, it is possible to reduce the means for protecting the vibration visualization radar 1 to one unit in order to avoid direct hits from rock fragments scattered by blasting or crushed stone rebounded by spraying.

[0042] Furthermore, according to this embodiment, the complicated processing required to operate two vibration visualization radars simultaneously as in the background art is not required, so it is possible to reduce the effort required to create the measurement system and the costs required to use the vibration visualization radar 1.

[0043] Furthermore, according to this embodiment, since the vibration visualization radar 1 is installed near the top end, it becomes possible to emit radio waves from above the construction machine. Therefore, according to this embodiment, it is possible to minimize the areas where reflected waves are not observed, without having to install vibration visualization radars on both the left and right sides as in the background art.

[0044] Furthermore, according to this embodiment, since the receiving antennas 1a of the vibration visualization radar 1 are arranged in the vertical direction, it is possible to improve the degradation of spatial resolution near the top end.

[0045] Furthermore, according to this embodiment, the vibration visualization radar 1 is installed at a position approximately 1 to 2 m to the left or right of the center of the top end, so it is possible to effectively avoid the occurrence of pixels that become indistinguishable due to the distance between the vibration visualization radar 1 and the pixels on the face being equidistant. [Explanation of symbols]

[0046] A. Face monitoring system H Excavation surface S steel shoring T-Tunnel W Face 1. Vibration Visualization Radar 2 Computer (detection device) 3 Installation stand 3a, 3b vertical frame 3c Lower frame 4 Pan head

Claims

1. In a face monitoring system for monitoring the face during tunnel excavation work, A vibration visualization radar that transmits a monitoring wave to the face and receives a reflected wave of the monitoring wave; a detection device for detecting a change in the face based on a received signal from the vibration visualization radar, A face monitoring system characterized in that the vibration visualization radar is fixed to a location near the top of the tunnel.

2. The face monitoring system according to claim 1, characterized in that the vibration visualization radar is fixed to a steel support constructed in the tunnel via an angle iron.

3. 3. The face monitoring system according to claim 1 or 2, characterized in that the vibration visualization radar has receiving antennas arranged in a vertical direction.

4. In a face monitoring system for monitoring the face during tunnel excavation work, A first step of transmitting a monitoring wave from one vibration visualization radar to the face and receiving a reflected wave of the monitoring wave by the vibration visualization radar; and a second step of detecting a change in the face based on a signal received by the vibration visualization radar, A method for monitoring a tunnel face, characterized in that the vibration visualization radar is fixed to a location near the top of the tunnel.

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