JPS6014316B2 - Earthquake early detection warning system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an earthquake early detection and warning system that detects earthquakes as quickly as possible, estimates the damage area, and issues warnings only for earthquakes that are truly harmful. .

Trains traveling at high speed on railway tracks are in an extremely dangerous situation if they encounter a large earthquake while traveling.

For this reason, equipment for detecting earthquakes is installed along each railway line, and they constantly monitor the occurrence of earthquakes. Conventional earthquake detection and warning systems issue a warning that a dangerous rocky area has occurred when the amplitude value of an earthquake detected by a detection device exceeds a predetermined limit value (for example, horizontal ground motion 4 female). The plan was to temporarily stop the train by ordering the train to brake suddenly, and then, after confirming Ikefuji's safety, the train would resume running late. In railways such as the Japan National Railways Shinkansen, which conducts highly centralized train management, the amount of information exchanged between the train commander and the trains is enormous, so information is To prevent mistakes, orders for emergency train stops are implemented by stopping the pumps in the relevant section. Once flea digging is stopped in this substation facility, it is difficult to restart the operation for a short period of time due to the safety confirmation work required by regulations. Therefore, once a substation is ordered to stop supplying power after detecting pond motion that exceeds the limit level, it is likely that the earthquake will be confirmed to be safe within a relatively short period of time. Even so, it will take a considerable amount of time before Kiryu is restarted. Therefore, when setting this limit level, it is necessary to set it to a high value that is as high as possible to the extent that damage may occur, thereby minimizing interruptions in train transportation due to non-dangerous land misses. There is. However, in order to reliably guarantee the safety of train entrainment, it is necessary to allow for a certain degree of safety factor when setting the limit level. Therefore, in such an earthquake detection and warning system, it is inevitable to some extent that trains will be stopped even by an earthquake that is not dangerous. The present invention detects the occurrence of an earthquake as soon as possible, and when an earthquake is detected, calculates the epicenter element and estimates the magnitude based on the data obtained at that time, and uses the results. The number of damaged castles is estimated, and whether or not the railway line being laid is included in the damaged castle or not is determined to be a cause of harm, and if it is determined that there is a cause of harm, the railway in that section is immediately stopped. etc. to stop the train from traveling.

If it is not determined that the earthquake is causing damage based on the data at this point, new input data will be imported and the process described above will be continued until the earthquake is determined to be causing damage or the earthquake ends. Judgments as to whether or not there is any potential for causing damage are made repeatedly, and by detecting ground love early in the initial tremor stage and determining whether or not it is causing any damage at a relatively early stage after detection, there is sufficient free time. This provides an earthquake early detection and warning system that can issue a warning only when the detected earthquake is truly damaging, and for all earthquakes that are truly damaging. Therefore, when applied to the earthquake detection and warning system along railway lines as described above, the substation's quake will stop and the train will stop only if the detected earthquake is truly dangerous. The disturbance of the diamond can be minimized and stopped, making it extremely effective. A detailed explanation will be given below based on examples. FIG. 1 is a diagram showing the arrangement array of detection points in the present invention. In the figure, 1 is a railway track, 2 is a substation for shipping to track 1,
Reference numeral 3 indicates observation points arranged at intervals of approximately 100 objects along the railway line 1, and reference numerals 4 indicate detection points distributed at several locations in the vicinity of this observation point 3 at 3 to 5 points. Each substation 2 supplies electric power to the track 1 in its assigned section for transporting trains, and adjacent substations 2 are connected by remote control lines 5 to exchange information between each other. is being carried out. In addition, as shown in FIG. 2, each observation point 3 has an observation point device 30 connected to the nearest substation 2 by a communication line 6.
is installed, and information such as the above-mentioned Kiryu stop command is sent from the observation point device 30 to the corresponding substation 2 via this communication line 6 (and the remote control line 5 if necessary). A detection point device 40 is installed at each detection point 4, each of which is connected to the observation point device 30 via a transmission line 7, and sends ground data of the detection point to the observation point device 30. here,
In order to detect the occurrence of an earthquake more quickly, it is advantageous to install the sensor in an agricultural area, including the ocean floor, or in a location closer to the area, taking into consideration the propagation speed of seismic waves.

This earthquake-prone area has been clarified to some extent by the results of research on seismic activity to date. In other words, if we take the Tohoku region as an example, many of the earthquakes have their epicenters on the ocean floor, such as off the coast of Tokachi, off the coast of Sanriku, off the coast of Miyagi Prefecture, off the coast of Fukushima Prefecture, and in the Kashima-nada Sea, and are concentrated on the Pacific Ocean side. Extremely rare. Therefore, earthquake countermeasures for railways in this region include, for example, Hachinohe, Miyako, Ofunato, Mt. Kinka, Soma, Iwaki, Choshi, Miura Peninsula, etc.
It will be effective to place observation points 3 at appropriate intervals along the Pacific coast. Approximately five detection points 4 are installed around the observation point 3 selected in this manner. When calculating the seismic source element based on observation data, the unknowns are the coordinates of the epicenter x and Y, the depth of the epicenter Z, the propagation velocity of the Ikejo wave v,
This is because there are five equations by Toki Hatto et al., and in order to obtain them, it is necessary to create simultaneous equations with five elements using data from five locations. In this layout example, taking into consideration the possibility of missing sides, five detection points 4 are set, and the observation data from six locations, including those from observation point 3, are occluded to determine the epicenter element. is being calculated. Therefore, if you want to reduce the number of detection points 4 for economic reasons etc., by assuming the value of one or both of the propagation velocity v and the depth of the epicenter Z in advance, it is possible to reduce the number of detection points 4 from 4 or 3 points. If there is observation data, it is possible to calculate the seismic focal elements, and by setting up at least two detection points 4, the objective can be achieved. Each detection point 4 is set at three to five places around the observation point 3. The propagation speed of incoming seismic waves, especially longitudinal waves (hereinafter referred to as P waves), is usually around 8 objects/sec near the ground surface, and the initial part of the seismic waves travels from observation point 3 and all detection points 4 connected to it to 1. Since it passes within ~2 seconds, false detections due to malfunctions, noise, etc. can be reduced if the initial motion is detected at multiple locations. Here, the transmission line 7 connecting each detection point device 40 and the observation point device 30 or the communication line 6 connecting the observation point device 30 and the substation 2 includes an optical fiber or the like. When used, it is extremely effective as a noise countermeasure because it is not affected by induced noise such as lightning. Furthermore, it is also effective to use radio as the transmission line 7 and the communication line 6. That is, if it is wireless, the transmission line or communication line itself will not be cut off due to damage caused by an earthquake, and communication will not be completely cut off unless there is damage to the transmitting and receiving equipment. Figure 2 shows the observation point equipment 30 and the detection point device 4 that are reinstalled at the observation point 3 and detection point 4 arranged and set in this way.
FIG. 2 is a block diagram showing an example of 0.

In the figure, numeral 31 is a sensor for detecting ground motion, and is of a type that detects, for example, three components of ground motion in the vertical direction, east-west direction, and north-south direction. Further, 32 is an amplifier that amplifies the detection signal from this sensor 31, 33 is a buffer amplifier, and 34 is a receiving device that receives signals sent from each detection point diamond layer 40 via the transmission line 7. , 35 analyzes the observation data of the ground sent from each detection point device 40, etc. from time to time, identifies the occurrence of ground love, and determines its culpability, and if it is determined that there is culpability. 36 is a control processing device that generates an alarm signal, 36 is a transmitter for sending this alarm signal to the substation station 2 in the middle of the day, and 37 is a clock device that generates accurate time information. It is. Observation point Hishitaka 30 is composed of these various devices. Further, in the figure, 41 is a sensor for detecting ground motion, for example, a type that detects only one vertical component of ground motion, and 42 is a sensor for sending the detection output signal to the transmission line 7. It is a transmitting device. The detection point device 40' is mainly composed of these two devices. In this embodiment, the observation point device 30 is the sensor 3
1, but it is not necessarily necessary to include the sensor 31. By increasing the number of detection points by one and installing a sensor equivalent to the sensor 31 of the forehead zero point device 30 here, the above-mentioned It is possible to build a system with exactly the same functionality as .

In this case, the position of the observation point 3 can be determined without considering whether or not it is suitable for detecting the ground data, so the arrangement of the observation point device 30, the dispatch of observers, etc. can be prioritized. Taking this into consideration, it becomes possible to select a location with convenient transportation. Further, FIG. 3 is a block diagram showing an example of a communication control section in the substation 2. As shown in FIG. In the figure, 21 is a remote control receiving device for receiving signals sent from the adjacent substation 2 via the remote control line 5, and 22 is a remote control receiving device for transmitting or transferring signals to the adjacent substation 2. This is a remote control transmitter for sending signals to the thin control line 5. Further, 23 is a receiving device that receives a feeding stop command, etc. sent from the observation point device 30 via the communication line 6, and 24 controls the operation of the substation equipment in response to the feeding stop command, etc. A control device 25 is a relay that responds to this control signal. Further, 26 is a transmission/reception control device which controls transmission and reception in these various devices, 27 is a storage device, and 28 is a signal bus interconnecting all these devices. The communication control section shown in FIG. 3 is for a substation that is directly connected to the observation point device 30 by the communication line 6, and the communication control section in the substation that is not directly connected is the receiving device 23. Not equipped with In this case, the turtle stop command and the like from the observation point device 30 are sent from the adjacent substation via the control line 5 in the same way as normal interruption information. The operation of the embodiment shown in the block diagrams of FIGS. 1 to 3 will be described below.

Each sensor 31 and 41 belonging to the observation point device 30 or the detection device 40 constantly detects ground motion at the point where each sensor is installed, converts this into an electrical signal, and sends it to the control processing device 35. The control processing device 35 controls each detection point 4
The information from the sensor 41 is transmitted to the transmitter 42 and the transmission line 7.
, received via the receiving device 34 and sent to the sensor 3 at the observation point 3.
1 through an amplifier 32 and a buffer amplifier 33. The control processing device 35 monitors the ground motion information that is continuously sent, and considers that a ground blind has occurred when the observed value exceeds a predetermined reference value. Observations for detecting the occurrence of this ground complex include various values such as the energy output of seismic waves, the root mean square value of the amplitude of seismic waves, and the cross-correlation of seismic waves from the sensor 31 at observation point 3 and the sensor 41 at each detection point 4. I can think of things. As mentioned before, in this example, we assume a detection and warning system that sends out a warning only when a truly destructive earthquake is detected, so the judgment is based on the three types of observed values mentioned above. The occurrence of an earthquake is detected by combining the results. First, we will discuss detection based on the energy output of seismic waves. The control processing device 35 takes in information on each component of the ground motion detected by the sensor 31 and constantly sent at predetermined time intervals (for example, at a sampling rate of 100 to 300 Hz), and calculates the average of the past sampling information. First, the drift level is calculated based on the value.

This drift level is constantly updated based on sampling information obtained from time to time. Next, the sensor 31
is detected and sent from time to time. vertical direction,
Values x, , x2 obtained by removing the drift level from the sampling values of the three components of the east-west direction and north-south direction.
, x3, the energy output y, is calculated. This calculation is based on the corrected sampling value x of each component mentioned above,
It is found in the form of the sum of the squares of , average, and . Control processing device 3
5 compares the calculation result of this energy output with a predetermined reference value each time, and calculates the energy output y,
The arrival of seismic waves is detected by monitoring whether or not it exceeds the standard value Y. Next, the detection of the arrival of seismic waves using the root mean square value of the Ikebuki amplitude will be described.

First, the control processing device 35 samples one of the ground shift signals detected by the sensor 31 or 41 and constantly sent, for example, vertical movement information of the sensor 31, in the same manner as described above, and sequentially transfers it to the memory. This memory has n storage areas and stores n sampling values in the past.
Each time new information is input, the oldest information overflows and disappears, and the sampled values are stored after removing, for example, the drift level. Next, each time the control processing device 35 writes a new sampling value to the memory, the control processing device 35 writes information xt, .
xt2, . The calculation result y2 of the root mean square value is compared with a predetermined reference value Y2 each time, and it is monitored whether the root mean square value 2 exceeds the reference value Y2 or not, and the arrival of seismic waves is detected. To save calculation time and storage area, the average can also be calculated by exponential averaging. Furthermore, the detection of the arrival of ground waves using the cross-correlation of seismic waves from the sensor 31 at the observation point 3 and the sensor 41 at each detection point 4 will be described.

First, the control processing device 35 samples the vertical motion component of the ground motion information from the sensor 31 and the ground motion information from each sensor 41 in the same manner as described above, and sequentially stores the memorandum in the overflow format as described above. go. This sampled value is stored after removing the drift level, for example. The cross-correlation is between sensor 31 at observation point 3 and detection point 4.
The information of the sensor 41 can be obtained in the form of the sum of products of each piece of stored information in the stored memory. Therefore, there are five cross-correlations ap, , ap between observation point 3 and each detection point 4.
2,...ap5 is obtained. The control processing device 35 constantly compares each cross-correlation api obtained in this way with a predetermined reference value Ap, and when a plurality of cross-correlations ap exceeds the reference value Ap, seismic waves are detected. Detects that it has passed. The control processing device 35 determines the arrival of seismic waves based on a combination of the determination results based on the energy output, root mean square value, cross-correlation, etc. described above.

Therefore, the arrival of seismic waves will not be accidentally detected due to the introduction of large noise or malfunction of instruments.

Furthermore, the observed values used to determine the arrival of seismic waves need not be limited to these three types, and other observed values such as the amplitude value of seismic waves may be used.

The control processing device 35 that detected the arrival of seismic waves in this way
samples the geophysical information from each sensor 31 and 41 in the same manner as described above, constantly updates each maximum value in memory based on this, and starts calculating the seismic source element using this value. . That is, the measurement values of each sensor 31 and 41 are processed to remove the influence of drift, and based on this, the time of the earthquake is calculated, and the coordinates X, Y of the epicenter, the depth Z of the epicenter, the shadow distance △, Calculate the seismic source elements such as the Mino direction and the velocity vp of the earthen wave. Then, it is determined whether the seismic wave being observed is a longitudinal wave (concentration wave, hereinafter referred to as P wave) or a transverse wave (torsion wave, hereinafter referred to as S wave). The propagation speed of P waves is much faster than that of S waves.
It becomes possible to distinguish between waves and S waves. Magnitude estimation calculations are performed based on the calculation results of the source elements and the maximum amplitude value from the time the earthquake is detected until a predetermined time. P
Various methods have been proposed for estimating the magnitude due to waves, but all of them are calculated from the foundation center distance Δ and the amplitude value of the ground motion at the observation point 3 or the detection point 4. Furthermore, when it is determined that it is an S wave in the determination of whether it is a P wave or an S wave, the distance between the blinds is calculated, and the magnitude Ms is estimated.

Various methods have been proposed for estimating the magnitude of S-waves using the center distance Δ and the maximum amplitude value, as in the case of P-waves. In this case, recalculating only the ant source element center distance △ is because the line center distance △ is a value that is directly related to the estimation of magnitude Ms, and also has higher accuracy compared to that obtained by P waves. This is because it can be found by When the estimated magnitudes Mp and Ms are calculated in this way, the control processing device 35 estimates the area where serious damage is expected to occur, and determines the degree of damage it will cause to the railway track 1. do.

In general, the spread and magnitude of the area affected by an earthquake are
The relationship with de is quite complicated. In other words, it is highly unlikely that the disaster-affected areas are distributed in the same D-circle shape with Joo as the center, and the shape is usually extremely complex. However, there is a strong correlation between the area where damage occurs and the magnitude, and the distance from Minato to the farthest point #3 where damage spread or the radius R of the disaster area is calculated by taking the logarithm of the radius R. .

gR=A・M−B However, M: Magnitude, A, B
;The relationship can be approximated by a simple linear expression such as a constant.

Next, it is determined whether the railway line 1 passes through an area where serious damage is expected to occur as estimated in this way. If the railway line 1 passes through the estimated area, there is a possibility of damage caused by the rock, so it is determined that the rock is causing damage, and a process is performed to send a rock stop command. Also,
Even if it is determined that there is no harm caused, the maximum amplitude value LM of the seismic wave up to that point will be a predetermined constant value LC (
For example, if the value is larger than 40 baits 1), a dragon stop command is sent out in consideration of the possibility of damage. If it is determined that there is no harm caused by the above determination, it is determined at that point whether the earthquake has ended or not.

When the end of the earthquake is detected in the end determination process, the process returns to the earthquake monitoring process using energy output, root mean square value, cross correlation, and the like. If the earthquake has not yet ended at the time of the determination process, the process returns to the process of determining whether it is a P wave or an S wave and the above-described process is repeated again. If it is determined that there is a harmful effect, or if the maximum amplitude exceeds a predetermined value, the control processing device 35 sends a command to stop the rope to the corresponding substation 2 as described above.

That is, this fin stop command is sent to the communication line 6 by the transmitting device 36 with information specifying the relevant substation added. At the substation where the receiving device 23 receives this information, the reception control device 26 determines whether the information is addressed to the substation itself or another substation, and if the information is addressed to the Ike substation, the reception control device 26 determines whether the information is addressed to the substation itself or another substation. It is transferred to the destination substation via the restricted transmission device 22 and the unrestricted line 5. At the crab station that receives the dew stop command, the control device 24 controls the relay 25 to stop the operation of the feeding equipment. As a result, the train in the corresponding line section is stopped and the train is stopped. After that, the maintenance personnel will confirm the actual damage.
Recovery processes such as repairing the damaged parts will be carried out. The flowchart in FIG. 4 diagrammatically organizes this series of processing procedures. Although the embodiments applied to earthquake detection along railway lines have been described above, the present invention should not be limited only to this, and can be applied to nuclear plants, chemical plants, etc.
Although it takes a lot of time and economic burden to resume operation once the operation has been stopped, it goes without saying that it is extremely effective as a disaster prevention measure.

In this way, the present invention detects earthquakes at an earlier stage and issues a warning only when the earthquake is truly harmful, so there is no need to stop operations of trains, plants, etc. When applied to earthquake warning systems for Shinkansen trains, unnecessary disruptions to timetables can be prevented, and when applied to earthquake warning systems for nuclear or chemical plants, the economic effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the equipment arrangement of an earthquake detection and warning system according to the present invention, FIG. 2 is a block diagram showing an embodiment of the present invention, FIG. 3 is a block diagram showing an example of a substation, and FIG.
The figure is a flowchart for explaining the operation. 1... Railway track, 2... Substation, 3... Observation point, 4
...Detection point, 5... Remote control line, 6...
...Communication line, 7...Transmission line, 21...
...Remote control receiving device, 22...Remote control transmitting device, 23.
... Receiving device, 24 ... Control device pupil, 25
... Relay, 26 ... Transmission and reception control device, 30 ... Observation point device, 31 ... Sensor,
32...amplifier, 33...batshua amplifier, 34...
- Receiving device, 35... Control processing device, 36...
... Transmitting device, 37... Clock device, 40...
...Detection point device, 41...Sensor, 42...
...Transmission device. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A system for detecting the occurrence of an earthquake, determining its causing damage, and issuing a warning only for earthquakes that are considered to be truly damaging, and for all earthquakes that are truly thought to be causing damage. In an earthquake early detection warning system, multiple detection points are selected and a detection point device equipped with a sensor and a transmitter is placed at each of them, and each detection point device is connected to a receiver, a control processing device, and a clock device. Connect to the observation point equipment equipped with a transmission line,
The ground motion information detected by each sensor is concentrated in the observation point device, and the control processing device uses the observed values of the maximum amplitude value, energy output, root mean square value, and cross-correlation of the seismic wave obtained from that information to detect the seismic wave. We constantly monitor the arrival of seismic waves, and if we detect the arrival of seismic waves based on multiple of these observed values, we determine that seismic waves have arrived, and first calculate the estimated epicenter and magnitude, and then determine the damage area based on this. Estimate
Earthquake early detection is characterized by issuing a warning to the relevant area for dangerous ones, and for other earthquakes, estimating the epicenter, magnitude, and damage area is repeated until the earthquake ends, and issuing a warning as necessary. alarm system. 2. The earthquake early detection and warning system according to claim 1, wherein the observation point device has a sensor. 3. Claim No. 3, characterized in that the process of sending out the alarm is carried out by harmonizing the determination of the degree of harm based on the estimation of the damage area and the observation of the maximum amplitude value larger than a predetermined reference value. Earthquake early detection warning system as described in Section 2. 4 Using the energy output, root mean square value, and cross-correlation of seismic waves as observed values for detecting the arrival of seismic waves, these three
4. The earthquake early detection and warning system according to claim 3, wherein the earthquake early detection and warning system determines that an earthquake wave has arrived when a detection result based on a combination of observed values indicates the arrival of an earthquake wave. 5. The earthquake early detection and warning system according to claim 4, wherein each sensor is arranged in an earthquake-prone area or a region closer to the area within a range of 3 to 5 km.