JPH10300729A - Rock ground collapse prediction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption and the cost for power supply facilities and to detect the collapse of a rock ground for a long time automatically by constituting a power supply mechanism with a solar cell and a battery and allowing a detection communication device to communicate only for a required short time. SOLUTION: A plurality of acoustic emission(AE) sensors 3 are installed near a rock ground that can be judged to possibly result in a collapse while they are fixed to the rock ground, and a count mechanism 4 counts the detection signals of the AE sensor 3. A power supply mechanism for the AE sensors 3, the count mechanism 4, and a universal communication mechanism 5 such as a portable telephone and a PHS is constituted of a solar cell and a battery. Then, a central control computer 2 successively oscillates a polling signal for ordering that a count signal should be transmitted only for a short time that is required for transmitting a count signal to each of a plurality of detection communication equipment 1. In this manner, a communication operation time is short, so that the power consumption required for communication needs to be small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rock-fall predicting apparatus which uses acoustic emission to centrally monitor the state of a plurality of rocks at a remote place and predicts the danger of rock-fall in advance. .

[0002]

2. Description of the Related Art In order to prevent the occurrence of accidents, especially human accidents, caused by the collapse of rocks facing roads, buildings, etc., in general, patrols are regularly conducted at places considered to be dangerous, and visual inspections are conducted. Although rock failure is predicted according to empirical judgment, accurate judgment cannot be obtained because the judgment criteria are extremely unclear, and therefore, serious human accidents should be prevented. It is not possible at present.

As a countermeasure against the current dissatisfaction, attention has been paid to a technique for utilizing the acoustic emission phenomenon for prediction of rock collapse.

That is, the collapse of the rock mass is caused by the collapse at the crack portion inside the rock mass as a whole. Acoustic emission sound (hereinafter referred to as AE sound)
Is generated, the AE sound is detected by an acoustic emission sensor (hereinafter, referred to as an AE sensor),
Based on the detected AE sound, the degree of the possibility of rock collapse has been determined.

FIG. 5 shows an example of actual measurement results in which a load is gradually applied to a rock to cause a collapse artificially. The stress generated in the rock is plotted on the left vertical axis, and an AE sound is generated per unit time. The amount of displacement is shown on the right vertical axis, and the amount of temporal displacement generated in the rock is shown on the horizontal axis. The curve A showing the stress-displacement characteristic changes almost directly in proportion to the stress and the displacement. Is generated, and a curve B showing the AE sound generation amount-displacement characteristic indicates that the value increases substantially at an acceleration as the stress and the displacement increase.

As is apparent from FIG. 5, since the AE sound has a property of increasing as the degree of rock destruction progresses, the frequency and change of the number of occurrences of the AE sound cause
It is possible to determine the degree of danger of the occurrence of rock collapse, and it has been confirmed that the energy of AE sound (amplitude of AE waves) generated as the rock fracture progresses increases. Therefore, this property is also used to determine the degree of danger of rock collapse.

[0007] As a conventional technique for predicting rock collapse using the AE sensor, an AE equipped with an AE sensor has been proposed.
A technology comprising: a sound measuring instrument, an analyzing means for analyzing a destruction position from a measured AE sound, an analyzing means for analyzing a destruction state generated from the AE sound, and a judging means for judging a degree of danger of collapse. Is disclosed in Japanese Patent Application Laid-Open No. Hei 7-134060.

According to the above-mentioned prior art, the monitoring of the rock state by the AE sound detection and the judgment of the degree of danger of the rock collapse can always be performed in real time, thereby obtaining a high reliability of the rock collapse prediction. It is thought that it is possible.

[0009]

However, according to the above-mentioned prior art, since the rock mass which is determined to be in danger of collapse to be installed with the AE sensor is generally a remote and remote place, It is almost impossible to obtain commercial electric power, so that a large-scale power supply must be provided, which causes a problem that the equipment cost becomes enormous.

[0010] Even if a large-scale power supply equipment is provided, the transmission of the AE sound detection information to the part that analyzes and detects the detected AE sound is, as described above, the location where the AE sensor is installed is remote. Since the remote location must rely on wireless communication means, in addition to the power required for AE sound detection by the AE sensor, a large amount of power is required for wireless communication, maintaining continuous operation for a long period of time. There is a problem that it is impossible to do so.

Accordingly, the present invention has been made to solve the above-mentioned problems in the prior art, and has as a technical object to reduce power consumption required for wireless transmission of detection information detected by an AE sensor. It is therefore an object of the present invention to make it possible to obtain power supply equipment on the AE sound detection side at low cost and to enable automatic detection of AE sound for a long period of time.

[0012]

Means for Solving the Problems Among the present invention for solving the above technical problems, the means according to the first aspect of the present invention is a method for fixing an AE sound generated on a rock and detecting and outputting the AE sound generated on the rock. The number of AE sensors and the detection signal from the AE sensor are input, and the number of times that the peak value of the detection signal exceeds a preset reference value is accumulated and stored, and stored by the output of the stored count signal. Clear
A counting mechanism for starting a new storage of the count signal;
It is composed of a general-purpose communication mechanism and a power supply mechanism composed of a combination of a solar cell and a battery, and is capable of communicating only for a short communication time required for transmission of a count signal at predetermined time intervals. Having a plurality of detection communication devices in a standby state, each of the plurality of detection communication devices sequentially transmits a polling signal for instructing transmission of a count signal within the communication time at a preset fixed time interval. Having a central management computer that determines the risk of rock collapse based on the received count signal,
It is in.

According to a second aspect of the present invention, in the first aspect of the present invention, the detection communication device includes a case where the cumulative number of AE sounds within a certain period exceeds a predetermined value, and a case where the AE sound peaks. When a value exceeds at least one of the abnormal values set in advance, a function of spontaneously transmitting a signal to that effect to the central management computer when the value becomes at least one is added.

[0014]

In each detection communication device installed in a remote place, the peak value of each signal wave of the AE sound detection signal from the AE sensor is compared with a preset reference value for each AE sensor fixed to the rock. Then, the signal wave having the peak value exceeding the reference value is sequentially accumulated and counted by the counting mechanism and stored as a count signal.

When a polling signal from the central management computer is received within the communication time of the detection communication device which becomes communicable at predetermined time intervals, the detection communication device transmits the count signal of each counting mechanism to the general communication. By the mechanism to send to the central computer in a preset order,
At the same time, each count mechanism is cleared by the output of the count signal, and the count mechanism is set to a standby state.

The central management computer, which receives the count signals in order from each of the detection communication devices, analyzes the received count signals from the plurality of AE sensors whose installation positions are known, and determines the degree of risk of rock collapse. Along with
Predict rock mass locations with high risk of collapse.

Each of the detection communication devices is in a standby state in which communication is possible only for a short communication time at predetermined fixed time intervals, and the actual communication operation time is shorter than the short communication time. Is even shorter,
Since the power consumption required for communication is extremely small, the power consumed by each detection communication device can be sufficiently covered by a power supply mechanism composed of a solar cell and a battery.

The battery constituting the power supply unit is
The detection communication device has a power capacity capable of supplying power required for all operations including communication of the detection communication device with a margin, and the solar cell at least consumes power consumed from the communication time to the next communication time. It has the power generation capacity to charge the battery.

As described above, since each detection communication device can be operated without supplying power from the outside, it is possible to combine a large number of detection communication devices with one central management computer. Extremely wide bedrock monitoring can be achieved with a central management computer.

According to the second aspect of the present invention, the case where the cumulative count number of the AE sound within a certain period exceeds a predetermined fixed value, or the case where the peak value of the AE sound exceeds a predetermined abnormal value. When an abnormal state such as a case, that is, a state in which the risk of rock collapse has clearly increased, the central management computer is notified as an emergency signal to that effect without waiting for the reception of the polling signal from the central management computer, and Have the management computer take immediate measures.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 3, the detection communication device 1 according to the present embodiment is provided with the AE sensor 3 fixed to the rock 7 near the rock 7 where it is determined that there is a risk of collapse facing the road 8 or the like. As shown in FIG. 2, a counting mechanism 4 which is a main part to which a desired number of AE sensors 3 are connected, a general-purpose communication mechanism 5 such as a mobile phone or a PHS,
Power supply mechanism 6 composed of battery 10 and solar cell 9
And a communication interface 11 for converting an output signal including a count signal of the counting mechanism 4 so that the general-purpose communication mechanism 5 can communicate.

The counting mechanism 4 is connected to each of the connected AEs.
It comprises a part corresponding to the server 3 and a control part for mainly controlling the operation of the general-purpose communication mechanism 5.

The parts corresponding to the individual AE sensors 3 are as follows:
The peak value of each waveform of the input AE sound signal is compared with a preset reference value, and the peak value of the waveform exceeds the reference value. When the first comparator and the output from the first comparator that are output at the same time are cumulatively counted and cleared by the output of the count signal, and when the count number within a certain period exceeds a predetermined value set in advance, It is composed of a counting section for performing an emergency output, and a second comparator for outputting when the peak value of the waveform of the AE sound signal exceeds a preset abnormal value.

The control unit sets the general-purpose communication mechanism 5 to a standby state in which communication is possible for a predetermined communication time at a predetermined time interval, and upon receiving a polling signal from the central management computer 2, counts each of the counting units. , And the general-purpose communication mechanism 5 is operated by an emergency output from the counting unit or an output from the second comparator.

The power supply mechanism 6 is composed of a combination of a battery 10 and a solar cell 9.
Has the ability to generate electric power corresponding to all of the power consumption of the counting mechanism 4 and the general-purpose communication mechanism 5 having
The surplus generated power of the solar cell 9 is equal to the battery 10
Is charged.

By attaching the A / D converter to the power supply mechanism 6, the voltage of the battery 10, that is, the voltage of the power supply mechanism 6 can be grasped, and therefore, the voltage signal of the A / D converter is received simultaneously with the communication of the count signal. By doing so, the state of the power supply unit 6 of each detection communication device 1 can be known on the central management computer 2 side, thereby making maintenance of the power supply unit 6 easy.

As shown in FIG. 1, the central management computer 2 receives signals from the plurality of detection communication devices 1 via the connected general-purpose communication mechanism, and performs each detection communication in a preset order and time interval. A polling signal is transmitted to the device 1.

The central management computer 2 analyzes the count signal from each of the detection communication devices 1 to judge the degree of occurrence of the collapse of the rock 7, and when the risk of collapse is high, the corresponding detection communication device 1 Along with issuing a warning signal, the related departments were notified to that effect, and the rock mass 7 where the risk of collapse increased was increased.
When the emergency communication of the counting unit or the output of the second comparator is transmitted from the detection communication device 1, an alarm signal is issued in the same manner as described above. I do.

FIG. 4 is a flowchart showing an operation example of the detection communication device 1. In step 1, the operation of the counting mechanism 4 is started or continued, and subsequently, in step 2, cumulative counting is performed, that is, the count number is stored. In the determination step of step 3, it is determined whether or not an alarm is being issued.
In the case of NO, it is determined whether or not the counted number stored in the next determination step 4 is within a predetermined value, and in the case of YES, the polling time from the central management computer 2 is close in the determination step 5. It is determined whether or not.

If the judgment in the judgment step 5 is YES, the general-purpose communication mechanism 5 is set in a standby state in a step 6, and it is judged in a judgment step 7 whether or not there is a polling signal.
In the case of ES, the count signal stored in step 8 is transmitted to the central management computer 2.

If the count signal has been transmitted, it is determined in a decision step 9 whether or not an alarm command has been received from the central management computer 2 within a predetermined period of time. If NO, the count signal is counted in a decision step 10 It is determined whether the number exceeds a preset fixed value or exceeds a preset abnormal value. If NO, the general-purpose communication mechanism 5 is turned off in step 11 and then the count mechanism 4 The stored count signal is cleared, the process returns to step 1, and the operation is repeated.

If it is determined in the determination step 5 that the polling time is near or not, it is determined that the polling time is close.
Then, the counting operation of the counting mechanism 4 is continued.

If it is determined in the decision step 7 that the polling signal is present or not, the decision step 13
Then, it is determined whether or not the communication time for putting the general-purpose communication mechanism 5 in the standby state has elapsed. If the determination is NO, the process returns to step 1 to continue the counting operation. After turning off the communication mechanism 5, the process returns to step 1.

If it is determined in step 4 that the stored count value is not within the predetermined value, the determination in step 1 is NO.
In step 5, the count signal is sent to the central management computer 2 voluntarily to make a determination step 9. In the determination step 9, it is determined whether or not an alarm command is received from the central management computer 2 within a predetermined time set in advance. If so, it is determined in step 16 whether or not an alarm is required. If NO, the process proceeds to step 12 to clear the stored count signal. If YES, road signal signage, siren, An alarm device such as a circuit breaker is actuated. If it is determined in step 10 that the count number of the count signal exceeds a predetermined constant value or exceeds a predetermined abnormal value, the process also proceeds to step 17. move on.

At decision step 3, it is determined whether or not an alarm is being issued.
If it is determined to be ES, it is determined in step 18 whether or not there is an alarm release command. If YES, the alarm device is stopped in step 19 and then the general-purpose communication mechanism 5 is turned off in step 11. Then, the process proceeds to step 12, where the memory of the counting mechanism 4 is cleared.

If it is determined in the determination step 18 that the alarm release command is not present (NO), a count signal is sent to the central management computer 2 in a step 20, and
In step 2, the memory of the counting mechanism 4 is cleared. In this case, since the alarm is being performed, the general-purpose communication mechanism 5 of the detection communication device 1 is maintained in the standby state.

[0037]

Since the present invention has the above-described structure, the following effects can be obtained. Since each detection communication device only needs to be in a standby state in which communication can be performed only for a short communication time at regular time intervals, it is possible to achieve a significant reduction in communication power that accounts for most of the power consumption of the detection communication device. This allows the operating power of the sensing communication device to be sufficiently provided by a power supply mechanism using a combination of a battery and a solar cell, thereby enabling the sensing communication device to be easily installed even in a remote remote place. The installation does not require a large expense.

Since communication between each detection communication device and the central management computer is achieved by using general-purpose communication equipment, it is possible to obtain a stable communication state without requiring much expense for the communication equipment.

According to the second aspect of the present invention, the increase in the risk of rock collapse is notified to the central management computer in real time, so that it is possible to quickly respond to the risk of rock collapse.

[Brief description of the drawings]

FIG. 1 is an embodiment diagram showing the entire configuration of the apparatus of the present invention.

FIG. 2 shows an embodiment of the detection communication device of the device of the present invention.
FIG.

FIG. 3 is a state diagram showing an example of an installation state of a detection communication device of the device of the present invention.

FIG. 4 is a flowchart showing an example of the operation of the detection communication device of the device of the present invention.

FIG. 5 is a characteristic diagram showing a characteristic of a relationship between an internally generated stress and a displacement amount and a characteristic of a relationship between an AE sound generation amount and a displacement amount when a rock mass is collapsed.

[Explanation of symbols]

 Reference Signs List 1; detection communication device 2; central management computer 3; AE sensor 4; counting mechanism 5; general-purpose communication mechanism 6; Characteristic curve a; point

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Muneaki Hatanaka 1-5-1, Otsuka, Inzai City, Chiba Prefecture Inside the Technical Research Center, Takenaka Corporation (72) Inventor Takao Ueda 8-21-1, Ginza, Chuo-ku, Tokyo No. Takenaka Corporation Tokyo head office (72) Inventor Masaaki Endo 1-490 Taiseicho, Omiya-shi, Saitama

Claims (2)

[Claims] A desired number of acoustic emission sensors (3) fixed to a bedrock (7) and detecting and outputting acoustic emission sound generated in the bedrock (7).
And a detection signal from the acoustic emission sensor (3), and counts and stores the number of times that the peak value of the detection signal exceeds a preset reference value.
A counting mechanism for clearing the storage by outputting the stored count signal and starting new storage of the count signal
(4), a general-purpose communication mechanism (5), and a power supply mechanism (6) composed of a combination of a solar cell and a battery, and necessary for transmitting the count signal at predetermined time intervals. For a short communication time only, the plurality of detection communication devices (1) which are in a standby state in which communication is possible, and the plurality of detection communication devices (1) are connected to the communication at every predetermined time interval. A central control computer (2) for sequentially transmitting polling signals for instructing the transmission of the count signal within a time period, and determining a risk of collapse of the rock (7) based on the received count signal. Collapse prediction device. 2. A method according to claim 1, wherein the detecting communication device (1) includes a case where the cumulative count number of the acoustic emission sound within a certain period exceeds a predetermined value, and a case where the peak value of the acoustic emission sound becomes a predetermined abnormal value. 2. The device according to claim 1, further comprising a function of spontaneously transmitting a signal to that effect to the central management computer (2) when at least one of the conditions is exceeded.