JP3095629B2 - Landslide detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to detect landslides such as landslides such as collapses, cuts, and landslides on railway tracks and roads with a sensor cable, and to distinguish between rockfall, landslides, wind and snow, and artificial contact. The present invention relates to a landslide detection device capable of detecting a landslide.

[0002]

2. Description of the Related Art Conventionally, this type of landslide detection device includes:
The one shown in FIG. 10 is known (Japanese Patent Publication 3-9).
247) and the following configuration. An optical fiber pile 53 is driven at predetermined intervals into the ground 50 where a landslide is to be detected, and an operation box 55 is attached to the upper end of the optical fiber pile 53 projecting from the ground. Through the optical fiber 54. Further, the invar wire 52 is pulled out from the operation box 55 and connected to the invar wire pile 51 which is separately driven.

In the operation box 55, as shown in FIG. 10B, the upper roller 56 and the lower roller 57 are constantly urged in the direction of the arrow by a spring (not shown). The upper roller 56 and the lower roller 57 are prevented from rotating by engaging with the cam 58 of the upper roller 56. Alternatively, as shown in FIG. 10C, the stopper 62 of the invar wire 52 holds the weight 60 so as not to fall. When the ground 50 slides and the optical fiber pile 53 is flushed, the stopper 62 is disengaged from the cam 58, and the upper roller 56 and the lower roller 57 rotate in the direction of the arrow. Bending occurs. Alternatively, the stopper 62 comes off, the weight 60 falls, and the cutter 61 cuts the optical fiber 54.

In normal operation, the optical pulse signal input from one end of the optical fiber 54 gradually decreases due to the transmission loss of the optical fiber 54, and the intensity of the backscattered light also gradually decreases. If the optical fiber 54 is locally bent as shown in FIG. 10) or if the optical fiber 54 is cut as shown in FIG. 10C, the intensity of the backscattered light is sharply reduced, causing a step in the characteristic line. . The landslide occurrence location is detected from the landslide occurrence time and the round trip time to the step of the light pulse from this step.

[0005]

In the landslide detection method as described above, the inva wire pile 51 and the optical fiber pile 53 are used.
Into the ground, an operation box 55 is attached to the upper end of the optical fiber pile 53 projecting from the ground, and one optical fiber 54 penetrates between the operation boxes 55. The installation work is extremely troublesome, such as connecting the invar wire 52 to the pile 51 for the invar wire that has been separately driven and pulled out.

[0006] Since the upper ends of the invar wire stake 51 and the optical fiber stake 53 are exposed to the ground, the inva wire may be exposed to external pressures other than landslides, such as wind, rain, snow, fallen trees, falling rocks, and animals. There is a risk that the stopper 62 of the 52 will come off and operate, and whether the landslide is a rockfall, a landslide, and whether it is due to wind, rain, snow, fallen trees, animals, etc., due to human contact, etc. Could not determine.

[0007] Further, in the method in which the upper roller 56 and the lower roller 57 are driven by springs, since they have mechanical driving parts, they may not operate if left for a long period of time.
0 and the cutter 61, the optical fiber pile 53 is used.
If the optical fiber 54 is tilted sideways due to a landslide, the optical fiber 54 may not be cut. Further, since the invar wire 52 must be installed in addition to the optical fiber 54, the structure becomes complicated and the invar wire 52 is installed. There was a problem that landslides in places that were not detected could not be detected.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a device which can be easily attached to existing equipment, can more reliably detect a landslide, and can distinguish between rockfall, landslide, wind and snow, artificial contact and the like. Things.

[0009]

SUMMARY OF THE INVENTION The present invention provides a landslide hazard.
We set up protection net 13 in area and prevent landslide
In the above device, a cable is connected to the protection net 13.
A sensor is attached, and this cable sensor is
And the cable sensor insulates the core wire 1
Covered with the body 2 and wrapped around the ground wire 3
A coaxial cable whose outer periphery is coated with an outer coating 4
And the core wire generated by the vibration of the protection net 13
The capacitance change between 1 and insulator 3 is detected as a voltage change.
The arithmetic and control unit 21 outputs the
Landslide by comparing the output voltage of the cable sensor with the threshold
It is characterized by consisting of one that calculates whether it is a detection signal
Landslide detection device.

[0010]

[Function] With such a configuration, a landslide,
Or, the protective net 13 vibrates due to other external pressure.
Then, the core wire 1 and the insulator 3 constituting the sensor cable
Between several mV and several hundred mV.
Is detected as a voltage change. The arithmetic control unit 21
Threshold of the integrated value of the output voltage detected by the sensor cable.
Then, whether the signal is a landslide detection signal is calculated. Integral
Alarm, light, display when value is greater than threshold
The occurrence of landslide is notified by a notification device such as a device.

[0011] Further , the present invention provides a cable sensor comprising:
And the second sensor cable 16. The first sensor cable 15 has a core wire 1, an insulator 2, and a ground so that the sensitivity is high in all ranges from a weak impact to a strong impact vibration. The second sensor cable 16 comprises a coaxial cable in which the wire 3 and the outer coating 4 are coaxially arranged.
Is formed by covering the outer periphery of the coaxial cable with a rubber pipe 19 and a stainless steel pipe 20 so as to be less sensitive to the vibration of a weak shock and to be more sensitive to the vibration of a medium or more strong shock. Is a discriminating circuit 29 for discriminating the content of the landslide based on the combination of the presence or absence of the output of the first sensor cable 15 and the second sensor cable 16.
A landslide detection device characterized by comprising: With such a configuration, in the determination circuit 29, the first
Output of sensor cable 15 and second sensor cable 16
If both are landslide detection signals, it is determined that a rock has fallen
A signal is output. Only the output of the first sensor cable 15
When a signal is detected, a signal indicating that a landslide has occurred is output.
You. Only the output of the second sensor cable 16 is detected
And a signal determined to be due to artificial contact is output.
You. First sensor cable 15 and second sensor cable
If neither output of 16 was detected, it was determined that there was no vibration
A signal is output.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a case where a landslide on a cliff 14 or an embankment 12 of a railway line 10 is detected using the landslide detection device according to the present invention. Such as a cliff 14 near the railway track 10 or an embankment 12 on which the railway track 10 is laid.
At a place where a landslide is to be detected, a net fence 8 with a protective net 13 is provided to ground the landslide detection device of the present invention. Further, in order to prevent landslides and falling rocks, a net fence 8 on which a protective net 13 is provided is provided in advance, or a cliff 14 or an embankment 12 is provided.
The protection net 13 is directly stretched on the surface of. In the first embodiment of the present invention, a case will be described in which a sensor is attached to these new or existing protection nets 13 and the presence or absence of a landslide is detected from the vibration of these protection nets 13.

When the landslide, rock fall, etc., the protection net 13 vibrates due to impact or partial damage, etc., the first sensor cable is used to detect a landslide from this vibration and output a signal. 15 and / or a second sensor cable 16 is attached directly to the protective net 13. The attachment to the protective net 13 is fixed at intervals of several tens of centimeters by the attachment 17. The attachment position is preferably at a place other than the intersection of the wire mesh in order to prevent the damage of the tightening band. If it is a band, it may be an intersection.

The first and second sensor cables 15, 1
6, when vibration occurs in the protection net 13, the vibration is transmitted to the first and second sensor cables 15 and 16, and the first and second sensor cables 15, 1 due to the tribo effect.
6, an electric signal is generated, and this signal is sent to the arithmetic and control unit 21.

Of these, the first sensor cable 15 is
As shown in FIG. 4A, the core wire 1 is covered with an insulator 2,
It consists of a coaxial cable in which an earth wire 3 is wound around the outer circumference and further coated with an outer coating 4 on the outer circumference. The sensitivity is set to be high in all ranges from a weak shock to a strong shock vibration. Further, as shown in FIG. 4B, the outer periphery of the first sensor cable 15 made of a coaxial cable was covered with a rubber pipe 19, and the outer periphery of the second sensor cable 16 was protected with a stainless steel tube 20. It is set so that sensitivity to vibration of a weak impact is low and sensitivity to vibration of a moderate or strong impact is high.

The first sensor cable 15 and the second
The sensor cables 16 may be used alone, but by combining two cables as a pair and performing processing on a circuit as described later, landslides and landslide Not only landslides, but also external pressures other than landslides, such as wind, rain, snow, fallen trees, falling rocks, and animals.

As shown in FIG. 5B, the first sensor cable 15 and / or the second sensor cable 16 are attached at predetermined intervals such as an upper stage, a middle stage, and a lower stage according to the size of the protection net 13. , Its length is from several tens of meters to several hundred
m. Also, the protective net 13 such as the embankment 12 other than the cliff 14 is similarly attached. Since the first sensor cable 15 and / or the second sensor cable 16 detects vibration of the attached cable, vibration is generated by a landslide such as a protective fence or a concrete spraying place in addition to the protective net 13. You may make it attach directly to a place. The first attached to the protection net 13
The sensor cable 15 and / or the second sensor cable 16, as shown in FIG. 5 (a), between the terminator 7 consisting of resistor <br/> antibody in their tip, the wire 1 and the ground line 3 Connected to. The base end of the first sensor cable 15 and / or the second sensor cable 16 is connected to the arithmetic and control unit 21. As shown in FIG. DC power supply 5 and voltmeter 6 are connected. In addition to the DC power supply 5, an arithmetic control unit 21, an output unit 22
The solar cell 9 can be used as a power source for the entire device or a part of the device, and the power may be supplied from a substation by a power cable. With such a configuration, the first sensor cable 15 and / or the second sensor cable 16 may generate
A capacitance change between the core wire 1 and the insulator 3 occurs, which is detected by the voltmeter 6 as a voltage change from several mV to several hundred mV , and output.
You.

The details of the arithmetic control unit 21 will be described with reference to FIGS. The arithmetic control unit 21 is connected to an absolute value circuit 24, an amplification circuit 25, and an integration circuit 26 connected to an input terminal 23 for the first sensor cable 15, and to an input terminal 30 for the second sensor cable 16. It comprises an absolute value circuit 31, an amplification circuit 32, an integration circuit 33, a first comparison circuit 27, a discrimination circuit 29, and a second comparison circuit 34. A first threshold input terminal 28 is connected to the first comparison circuit 27, and a second threshold input terminal 35 is connected to the second comparison circuit 34.

An output section 22 is connected to the output side of the arithmetic control section 21. The determination circuit 29 includes AND gates 36, 37, 38 and 39, as shown in FIG. Reference numerals 40, 41, 42 and 43 are output terminals.

The operation of the above configuration will be described.
When the protection net 13 vibrates due to a landslide such as a landslide or a falling rock, or other external pressure such as a wind, rain, snow, fallen tree, falling rock, or animal, the first sensor cable 15 and the second sensor cable 16 are vibrated. The voltmeter 6 detects a signal corresponding to the vibration as a voltage change of several mV to several hundred mV due to a change in capacitance between the core wire 1 and the insulator 3 due to the vibration, shock, or the like. And input to the input terminals 23 and 30, and are converted into absolute values by absolute value circuits 24 and 31. Amplifying circuits 25 and 32 amplify and integrate the signals in integrating circuits 26 and 33, respectively.

In the first comparison circuit 27, when the integration value of the integration circuit 26 is larger than the threshold value from the first threshold value input terminal 28, the signal is output to the output section 22 and a landslide is generated by the communication device. Notify the alarm. Similarly, in the second comparison circuit 34, when the integration value of the integration circuit 33 is larger than the threshold value from the second threshold value input terminal 35, the output unit 2
2 to notify a landslide occurrence alarm by a reporting device. Specifically, the alarm device includes an alarm device, a light emitting device, a display device, etc., which issues an alarm by the alarm device, signals the surrounding area with light by the light emitting device, and displays the signal on the display device of the train or the management room. .

The determination circuit 29 makes the following determination based on the presence or absence of signals from the first comparison circuit 27 and the second comparison circuit 34. (1) The fact that there are outputs from both the first comparison circuit 27 and the second comparison circuit 34 means that the first sensor cable 1
5 means that there is both a signal in the entire range from the weak shock to the strong shock vibration detected by 5 and the signal for the moderate to strong shock vibration detected by the second sensor cable 16. In this case, a signal indicating that a rock has been dropped is output from the AND gate 36 to the output terminal 40.

FIG. 6 shows a detection waveform when a large stone of about 10 kg or more rolls or collides with the protection net 13, where (a1) is an original waveform of the first sensor cable 15 and (a2). Is the original waveform of the second sensor cable 16,
Similarly, (b1) and (b2) are the respective absolute value waveforms, and (c)
1) (c2) is each integrated waveform. In FIG. 6, a signal corresponding to a moderate or strong impact vibration from the second sensor cable 16 appears for a long time (several seconds or longer). While the signal due to the large shock appears, the signal in the entire range from the weak shock to the vibration of the strong shock continuously appears from the first sensor cable 15. In the case of such a characteristic, a signal determined as a rock fall is output from the AND gate 36 to the output terminal 40.

FIG. 7 shows a number k which is slightly smaller than that of FIG.
With a similar detection waveform when the g stone rolls or collides with the protection net 13, a signal corresponding to a moderate or strong shock vibration appears from the second sensor cable 16 for a predetermined time or more, First sensor cable 1
From 5 onwards, the entire range of signals from weak shocks to strong shock vibrations appears continuously. Also in the case of such a characteristic, a signal determined as a rock fall is output to the output terminal 40.

(2) The fact that there is an output only in the first comparison circuit 27 means that there is a signal in the whole range from the weak shock detected by the first sensor cable 15 to the strong shock vibration, but it is medium or higher. Means that there is no signal for strong shock vibration. In the case of such characteristics, since the signal from the AND gate 37 to the output terminal 41 does not include a signal due to a large stone, a signal determined to be a landslide is output.

FIG. 8 shows waveforms detected by the first sensor cable 15 and the second sensor cable 16 when the protection net 13 has a landslide, and FIG.
(A2) is the original waveform of the second sensor cable 16, similarly (b1) and (b2) are the respective absolute value waveforms, and (c1) and (c2) are the respective integral waveforms. . A signal in the entire range from a weak shock to a strong shock vibration continuously appears from the first sensor cable 15, while a signal corresponding to a moderate to strong shock vibration from the second sensor cable 16 appears. Therefore, the output from the AND gate 37 to the output terminal 41 is a signal determined to be a landslide.

(3) The fact that there is an output only in the second comparison circuit 34 means that only a signal corresponding to vibration of moderate to strong impact detected by the second sensor cable 16 is present, Means that there is no signal in the entire range up to the vibration of this. This is due to artificial contact and is not considered to be due to landslide, so the output from the AND gate 38 to the output terminal 42 is artificial. A signal that is determined to be due to a temporary contact is output.

FIG. 9 shows waveforms detected by the first sensor cable 15 and the second sensor cable 16 when an instantaneous impact is applied to the protection net 13. FIG. (A2) is the original waveform of the second sensor cable 16, similarly (b1) and (b2)
Is an absolute value waveform, and (c1) and (c2) are integrated waveforms. Since almost no continuous signal from the first sensor cable 15 appears and only a signal from the second sensor cable 16 for moderate to strong shock vibration appears instantaneously, The output from the gate 38 to the output terminal 42 outputs a signal determined to be due to artificial contact.

(4) The fact that there is no output from both the first comparison circuit 27 and the second comparison circuit 34 means that signals in the entire range from weak shocks to strong shock vibrations are also moderately strong shocks. This means that there is no signal for vibration, which corresponds to the case without vibration, and the output from the AND gate 39 to the output terminal 43 is a signal determined to be without vibration.

These output signals from the discrimination circuit 29 are transmitted by an appropriate method such as wired or wireless, and are notified to train crews or other managers by train radio, local radio, signal lights, or the like. In particular, when a signal that has been determined as a falling rock or a signal that has been determined to be a landslide is output from the determination circuit 29, a light emitting device among the notification devices signals the surrounding area with light.

In the above embodiment, the first sensor cable 1
Although the case of the combination of the fifth sensor cable 16 and the second sensor cable 16 has been described, the first sensor cable 15 or the second sensor cable 16 may be installed alone.

[0032]

According to the present invention, a cable sensor that outputs vibrations as an electric signal is attached to a protective net 13, a protective fence, a concrete spraying point, or the like, which is installed in a landslide hazard area. Since it is connected to the arithmetic and control unit 21 for calculating whether or not the signal is a landslide detection signal, there is no mechanically movable part, so that it can operate reliably even if it is installed for a long time. Also, cable center
The core wire 1 is covered with an insulator 2 and a ground wire is
3 and the outer periphery thereof was covered with an outer coating 4.
A coaxial cable, which is
The resulting capacitance change between the core wire 1 and the insulator 3 is referred to as a voltage change.
The calculation control unit 21
By setting the threshold at
The types of landslides, such as
In addition to rocks, landslides, natural snow and snow, artificial vibrations, etc.
Can be different. In addition, some of the cable sensors
Buried in the sensor and vibration cannot be detected,
As long as vibration is applied to other parts
It works. Furthermore, it detects changes in vibration over time.
Landslides are temporary or continuous as they can
It can be observed whether it is changing on the way. Since the existing equipment such as the protection net 13, the protection fence, and the concrete spraying point can be used, the equipment can be provided at a low cost.

In the apparatus according to the present invention, the cable sensor comprises:
And the second sensor cable 16. The first sensor cable 15 has a core wire 1, an insulator 2, and a ground wire so that the sensitivity is high in all ranges from a weak impact to a strong impact vibration. 3, a second sensor cable 16 composed of a coaxial cable in which the outer coating 4 is coaxially arranged.
Is formed by covering the outer periphery of the coaxial cable with a rubber pipe 19 and a stainless steel pipe 20 so as to be less sensitive to the vibration of a weak shock and to be more sensitive to the vibration of a moderate to strong shock. The landslide is determined by the combination of the presence / absence of the outputs of the first sensor cable 15 and the second sensor cable 16 so that whether the landslide is rockfall, landslide, wind, More accurate whether it is due to rain, snow, fallen trees, animals, etc. or due to human contact
Can be determined .

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of installation of a landslide detection device according to the present invention.

FIG. 2 is a specific block diagram of a calculation control unit 21 of FIG.

FIG. 3 is a specific circuit diagram of a determination circuit 29 of FIG.

FIG. 4A is a sectional view of a first sensor cable 15,
(B) is a sectional view of the second sensor cable 16.

FIG. 5A is an electric circuit diagram when the first sensor cable 15 is attached, and FIG. 5B is a front view showing a state where the first sensor cable 15 and the second sensor cable 16 are attached to the protection net 13. FIG.

FIG. 6 is a characteristic diagram of the first sensor cable 15 and the second sensor cable 16 when a rock falls.

FIG. 7 shows a first example of a first sensor cable 15 when a rock falls.
FIG. 6 is a characteristic diagram of the second sensor cable 16.

FIG. 8 illustrates a first sensor cable 15 and a second sensor cable 15 when a landslide occurs.
6 is a characteristic diagram of the sensor cable 16 of FIG.

FIG. 9 is a characteristic diagram of the first sensor cable 15 and the second sensor cable 16 during artificial vibration.

FIG. 10 is an explanatory diagram of a conventional landslide detection device.

[Explanation of symbols]

1 core wire, 2 insulator, 3 ground wire, 4 outer coating,
5: DC power supply, 6: Voltmeter, 7: Terminator, 8: Net fence, 9: Solar cell, 10: Railroad track, 11 ...
Crushed stone, 12 ... embankment, 13 ... protective net, 14 ... cliff, 1
5: first sensor cable, 16: second sensor cable, 17: mounting fixture, 18: bare wire, 19: rubber pipe,
Reference Signs List 20 stainless steel tube 21 arithmetic control unit 22 output unit 23 input terminal 24 absolute value circuit 25 amplifier circuit 26 integration circuit 27 first comparison circuit 28 first Threshold input terminal, 29: discriminating circuit, 30: input terminal, 31: absolute value circuit, 32: amplifying circuit, 33: integrating circuit, 34: second comparing circuit, 35: second threshold input terminal , 36, 37, 38, 39 ... AND gate, 40,
41, 42, 43: output terminal, 50: ground, 51: invar wire pile, 52: invar wire, 53: optical fiber pile, 5
4: optical fiber, 55: operation box, 56: upper roller, 57
... Lower roller, 58, 59 cam, 60 weight, 61 cutter, 62 stopper.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Kobayashi 2-4-2-4 Shibata, Kita-ku, Osaka-shi, Osaka Inside West Japan Railway Company (72) Inventor Takanori Nakaoka 2-4-2 Shibata, Kita-ku, Osaka, Osaka No. 24 Inside West Japan Railway Company (72) Inventor Shinji Numao 2304 Takasaki, Kusazaki-cho, Inashiki-gun, Ibaraki Japan Inside the Koei Central Research Institute (72) Inventor Chisho Suwa 2304 Takasaki, Kusazaki-cho, Inashiki-gun, Ibaraki Japan Inside the Central Research Institute, Koei Co., Ltd. (72) Inventor Zhang Jihang, 2304 Takasaki, Kusazaki-cho, Inashiki-gun, Ibaraki Japan Japan Inside the Central Research Laboratory, Koei Co., Ltd. (56) References JP-A-62-225620 (JP, A) JP-A-48-55506 (JP, A) Jpn. (P, U) JP 58-51206 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01D 21/00 G01H 11/06

Claims (8)

(57) [Claims] 1. A device which is adapted to stretched the guard net 13 in landslide danger zone to prevent landslides, attach the Ke Burusensa the guard net 13, and connect the cable sensor arithmetic control unit 21 Do Ri, said cable
The bull sensor covers a core wire 1 with an insulator 2 and
A ground wire 3 is wound, and an outer coating 4 is further applied to the outer periphery thereof.
A coated coaxial cable, wherein the protective net 13
Capacitance between the core wire 1 and the insulator 3 caused by vibration
It detects the change as a voltage change and outputs it.
The arithmetic control unit 21 calculates the output voltage of the cable sensor.
Calculates whether the signal is a landslide detection signal by comparing with a threshold
Landslide detection device characterized by comprising the shall. 2. An apparatus for preventing a landslide by providing a protection fence in a landslide-hazardous area, wherein the protection fence is provided on the protection fence .
Install the Ke Burusensa, Ri Na connect this cable sensor arithmetic control unit 21, the cable sensor, core wire
1 is covered with an insulator 2 and a ground wire 3 is wound around its outer periphery.
Coaxial cable whose outer periphery is further coated with an outer coating 4
Caused by the vibration of the protective net 13
The capacitance change between the core wire 1 and the insulator 3 is defined as a voltage change.
The arithmetic control unit 21
Compares the output voltage of the cable sensor with a threshold value.
A landslide detection device for calculating whether the signal is a landslide detection signal . In apparatus that 3. A spraying concrete landslide danger zone to prevent landslides, attach the Ke Burusensa the concrete, Ri Na connect this cable sensor arithmetic control unit 21, the cable
The sensor has a core wire 1 covered with an insulator 2 and an outer periphery
The outer wire 4 is wound around the
A shielded coaxial cable,
The capacitance change between the core wire 1 and the insulator 3 caused by movement
And outputs it as a voltage change.
The arithmetic control unit 21 determines the output voltage of the cable sensor.
Calculate whether it is a landslide detection signal by comparing with the threshold
Landslide detection device characterized by comprising the stuff. 4. A cable sensor, the sensitive first sensor cable 15 in the entire range up to the vibration of the strong impact from weak impact, it covers the outer periphery of the coaxial cable, the sensitivity dull vibration weak shock, The arithmetic and control unit 21 includes a second sensor cable 16 that is highly sensitive to moderate or strong impact vibration. The arithmetic and control unit 21 determines whether a landslide occurs based on a combination of the presence or absence of the output of the first sensor cable 15 and the second sensor cable 16. 4. The landslide detection device according to claim 1, further comprising a determination circuit for determining the content of the landslide. 5. An apparatus in which a protection net 13 is stretched in a landslide-hazardous area to prevent a landslide, wherein a cable sensor for outputting vibration of the protection net 13 as an electric signal is attached to the protection net 13. This cable sensor is connected to an arithmetic control unit 21 for calculating whether or not the output is a landslide detection signal. The cable sensor includes a first sensor cable 15 and a second sensor cable 16, The sensor cable 15 of
The core wire 1, the insulator 2, the ground wire 3, and the outer coating 4 so that the sensitivity is high in all ranges from a weak shock to a strong shock vibration.
Are coaxially arranged, and the second sensor cable 16 has an outer periphery of the coaxial cable so that the sensitivity of the second sensor cable 16 is low for vibration of a weak shock and high for vibration of a moderate or strong strong shock. Rubber pipe 19 and stainless steel pipe 2
The arithmetic control unit 21 is provided with a discriminating circuit 29 for discriminating the content of the landslide based on a combination of the presence or absence of the output of the first sensor cable 15 and the output of the second sensor cable 16. A landslide detection device characterized by the following. 6. An apparatus in which a protection net 13 is stretched in a landslide-hazardous area to prevent a landslide, wherein a cable sensor for outputting vibration of the protection net 13 as an electric signal is attached to the protection net 13. This cable sensor is connected to an arithmetic control unit 21 for calculating whether or not the output is a landslide detection signal. The cable sensor includes a first sensor cable 15 and a second sensor cable 16, The sensor cable 15 of
The core wire 1, the insulator 2, the ground wire 3, and the outer coating 4 so that the sensitivity is high in all ranges from a weak shock to a strong shock vibration.
Are coaxially arranged, and the second sensor cable 16 has an outer periphery of the coaxial cable so that the sensitivity of the second sensor cable 16 is low for vibration of a weak shock and high for vibration of a moderate or strong strong shock. Rubber pipe 19 and stainless steel pipe 2
The arithmetic control unit 21 includes a discriminating circuit 29 for discriminating the content of the landslide based on a combination of the presence or absence of the output of the first sensor cable 15 and the output of the second sensor cable 16. The circuit 29 outputs a signal indicating that a rock has been dropped when there is an output from both the first comparison circuit 27 and the second comparison circuit 34, and a landslide occurs when only the first comparison circuit 27 has an output. Is output, and when only the second comparison circuit 34 has an output, a signal indicating that the signal is due to an artificial contact is output,
A landslide detection device which outputs a signal indicating that there is no vibration when there is no output from both the comparison circuit 27 and the second comparison circuit 34. 7. When a signal indicating a falling rock or a signal indicating a landslide is output from the discriminating circuit 29, an alarm, a light emitting device, a display device or the like is used to notify the user of the output. The landslide detection device according to claim 4, 5 or 6, wherein 8. The landslide detection device according to claim 1, wherein part or all of the device is operated by a power supply using a solar cell.