JPH05822Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a debris flow detection device that detects debris flows occurring in mountainous areas, rivers, and mountains.

[Conventional technology]

Traditionally, in mountainous areas where volcanic ash has accumulated or where there are steep slopes, debris flows often occur along rivers during torrential rains or prolonged rain, often causing damage to nearby residents. . Debris flows like this are caused by landslides that occur near the top of a mountain, or a flow of sediment that gradually grows larger.If detected in the early stages of occurrence near the top of a mountain, it is possible to block access to bridges and roads that are damaged by the debris flow. For example,
Damage can be prevented.

For this reason, in the past, as shown in Figure 4, detection lines 2 were installed on the opposing side walls 1a and 1b of the weir 1 upstream of the bridge, which could be damaged by a debris flow, to detect the occurrence of a debris flow. When the wire 2 is cut, a detection device 3 detects this and issues a warning. The speed of debris flow is 8km/h~12
Km/H, and if detected at an appropriate location on the upstream side, damage can be prevented.

[Problem that the invention attempts to solve]

Damage can be prevented by blocking downstream traffic when a debris flow is detected.
Depending on the severity of the debris flow, it may not be necessary to block traffic. If the road where traffic is blocked is a community road, the impact of the blockage is significant, so it is desirable not to block traffic unless there is a problem, but conventional methods cannot make this determination.

[Means for solving problems]

In order to solve such problems, this idea is
It is equipped with a device that detects when the river bed has become shallower than a predetermined value, a device that detects the occurrence of a debris flow, and a warning circuit that generates a warning signal when a detection signal is generated from both devices. be.

[Effect]

A warning signal is sent out when there is a real need to block traffic.

[Embodiment] Fig. 1 is a block diagram showing an embodiment of this invention, where 4 is a light emitter that emits infrared light, and 5 is a light receiver that receives the infrared light generated from the light emitter 4. Sediment outflow end 1d of sediment outflow section 1c
The height h of the weir is 20 to 30 cm, and the distance d from the downstream wall 1e of the weir is 30 to 50 cm, as shown in Figure 2.
If the positions of the emitter 4 and the receiver 5 are set to be at a position of cm, the infrared rays will not be blocked by accumulated earth and sand, large stones, or people walking on the dam. Reference numeral 6 indicates an alarm circuit that generates a warning signal when no signal is obtained from the receiver 5 for a predetermined period of time, and when a debris flow occurs, these devices are installed at a point several hundred meters to 2 km upstream of the location where damage occurs. provided.

10 is a river that will be damaged if a debris flow occurs;
11 and 12 are ultrasonic transceivers and thermometers protruding from the river bank toward the river; 13;
1 is a river bed depth measuring device that calculates the river bed depth of the river 10 based on the signals obtained from the ultrasonic transceiver 11 and the thermometer 12; 14 is a warning depth setting circuit; and 15 is a river bed depth warning device. A determination circuit 16 sends out a riverbed warning signal when the depth becomes shallower than the depth set by the depth setting circuit 14, and a warning circuit 16 sends out a warning signal when both a warning signal indicating that a debris flow has occurred and a riverbed warning signal are generated. It is a circuit. Note that 7 is a connection line.

The operation of the device configured in this way is as follows. The light emitter 4 includes an oscillation circuit (not shown), an infrared light emitting diode, and a lens inside.
The pulse signal generated by the oscillation circuit is converted into an infrared pulse signal by the infrared light emitting diode,
The light is condensed by a lens into parallel light beams, which are projected toward the light receiver 5. The photoreceiver 5 receives this infrared pulse signal and converts it into an electric signal, and outputs a DC voltage while receiving the infrared pulse signal.
It is configured so that when it is cut off, it becomes 0V.

Now, when a debris flow occurs at time t1, the infrared pulse signal is blocked by the debris flow, and the output signal of the receiver 5 changes from the "1" level to the "0" level, and this change is transmitted to the alarm circuit 6. Reportedly.
The alarm circuit 6 has a timer and a flip-flop (not shown) inside it, and when the input signal reaches the "0" level, the timer starts operating.
If the input signal remains at the "0" level for longer than the time set by the timer, the flip-flop operates and generates an alarm signal. For this reason,
When the input signal reaches the "0" level at time t1 as shown in FIG. 3a, the timer starts operating as shown in FIG. 3b. If the input signal continues at the "0" level until time t2 when the timer's operating time has elapsed, the flip-flop operates and an alarm signal is sent out, as shown in FIG. 3c.
If a person confirms the condition of the debris flow and manually resets it after determining that the level of danger is low, the reset signal shown in Figure 3d will be generated and the alarm will be reset by the reset signal. It is becoming more and more common.

Next, if the input signal shown in a is intermittent within the timer setting time T, as after time t5 in Figure 3, the timer will be reset in synchronization with the intermittent input signal, as shown in b. Therefore, no alarm signal is generated. In other words, if the received pulse signal returns to normal, there is no need to issue an alarm because the amount of debris flow is small and it is safe. Since the input signal is intermittent even when there is a problem, the system is designed not to generate an alarm in such cases.

If a debris flow is detected using this method, if the river bed has just been constructed, the river bed is low, so a large amount of debris flow will either bury the river bed, or it will not reach the bridge area and will only bury the river. It may end with . In such a case, the road surface is not affected, and if this road is a community road, blocking the road because a warning has been issued would have a huge impact on residents. For this reason,
It is better to measure the depth of the riverbed and only when the depth becomes shallower than a predetermined value will it be considered a real danger and send out a warning signal.

For this purpose, the ultrasonic transmitter/receiver 11 is directed toward the river 10 and ultrasonic waves are transmitted therefrom, and the river bed depth measuring device 13 measures the depth of the river bed based on the signal reflected from the river bed. At this time, since the speed of sound changes due to changes in atmospheric temperature, the riverbed depth measuring device 13 is connected to the thermometer 12 to prevent measurement errors due to temperature.
The measured value measured by the ultrasonic wave is corrected and output using the temperature data obtained by the . The warning depth setting circuit 14 sets the riverbed depth at which a warning should be issued, and the determination circuit 15 determines whether the value output from the riverbed depth measuring device 13 exceeds the value set by the warning depth setting circuit 14. It is designed to send output as follows. Further, the warning circuit 16 is
When both the output signal from the judgment circuit 15 and the output signal from the judgment circuit 15 are supplied, a warning signal is sent out.

With this configuration, if a debris flow occurs at the weir 1 and this is detected, the alarm circuit 6 will be activated.
An alarm signal is sent to the warning circuit 16, but at this stage the warning circuit does not yet send out a warning signal. Since the river bed depth measuring device 13 measures the river bed depth every moment, when the debris flow that occurred earlier reaches the river depth measurement point, it is detected that the river bed depth has become shallower. If the depth of the river bed at this time becomes shallower than the depth set by the warning depth setting circuit 14, the determination circuit 15 generates an output signal.
Warning circuit 16 sends out a warning signal indicating that a truly dangerous condition has occurred.

Note that if a few centimeters of error in measuring river bed depth is not a problem, the thermometer can be omitted.

[Effect of idea]

As explained above, this device generates a warning signal when the depth of the river bed becomes shallower than a predetermined value after detecting a debris flow, which has the effect of accurately determining a truly dangerous situation. have

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of this invention, FIG. 2 is a side view of the weir, FIG. 3 is a waveform diagram of various parts, and FIG. 4 is a diagram showing an example of the conventional system. 1... Weir, 4... Emitter, 5... Light receiver, 6
...Alarm circuit, 7...Connection line, 10...River, 1
1... Ultrasonic transceiver, 12... Thermometer, 13...
...River bed depth setting device, 14...Warning depth setting circuit,
15... Judgment circuit, 16... Warning circuit.

Claims (1)

[Scope of utility model registration request] A debris flow detector that sends out a warning signal when a debris flow occurs at a sabo weir, a river bed depth measuring device that measures the river bed depth, and a river bed depth measuring device that measures the river bed depth when a warning signal is generated and the river bed becomes shallower than a predetermined value. A debris flow detection device equipped with a warning circuit that sends out a warning signal.