TW201433809A - Earthquake prediction device - Google Patents

Abstract

Disclosed is an earthquake prediction device provided with a prediction value calculation unit that calculates, from a prediction formula, a prediction value (MMIvp) indicating the magnitude of expected ground motion according to a modified Mercalli intensity scale after sensors have begun detecting the ground motion of an earthquake, by using a maximum velocity value (Vumax), which is the maximum value among absolute values of a velocity component calculated by a vertical velocity calculation unit. The prediction formula is: MMIvp=[alpha]vlog10(Vumax)+[beta]v.

Description

Earthquake prediction device

The present invention relates to a seismic prediction apparatus that uses a modified Megali seismic intensity as a vibration index indicating the degree of earthquake shaking and predicts the degree of seismic shaking in the initial stage of vibration.

Nowadays, there is a device for instantaneously measuring the degree of earthquake shaking (Patent Document 1). This device detects the acceleration components of the three directions of vibration (upper and lower, east, west, north and south), calculates the acceleration by vector synthesis, and obtains the vibration index value indicating the degree of earthquake shaking based on the acceleration. Measure the degree of shaking of the earthquake.

There is also a device for predicting the degree of earthquake shaking at the initial stage of vibration (Patent Document 2). Among the acceleration components of the three directions of the above vibration, the acceleration component in the up and down direction has a larger property than the other acceleration components at an early stage.

Therefore, this device detects the acceleration component in the vertical direction of the vibration, and calculates an index value indicating the degree of earthquake shaking corresponding to the acceleration component, thereby predicting the degree of shaking of the earthquake.

Since the inventions described in the above Patent Documents 1 and 2 are all creations in Japan, the vibration index of either one is the intensity used by the Japan Meteorological Agency. But the vibration indicator is used internationally to revamp the intensity of the Megali earthquake (MMI: Modified Mercalli Intensity), the devices described in the above Patent Documents 1 and 2 cannot be directly used in countries other than Japan.

Therefore, when the devices described in the above Patent Documents 1 and 2 are used in Japan, it is necessary to consider the conversion of the vibration index from the intensity used by the Japan Meteorological Agency to the MMI, but because the MMI is a human body experience or an investigation of the disaster situation after the earthquake. The determined vibration index, so it is not used to mechanical measurement, can not be easily replaced.

On the other hand, there are several proposals for using MMI for mechanical measurement. For example, Wald et al. propose a method of estimating an MMI index based on vibration acceleration or speed (Non-Patent Document 1). In Japan, Mr. Nakamura also proposed a method of using MMI as a vibration indicator to measure the degree of earthquake shaking (Non-Patent Document 2).

Advanced technical literature:

Patent Document 1: Patent No. 4472769

Patent Document 2: JP-A-2009-68899

Non-Patent Document 1: "Relationships between Peak Ground Acceleration, Peak Ground Velocity, and Modified Mercalli Intensity in California" David J. Wald, Vincent Quitoriano, Thomas H. Heaton, and Hiroo Kanamori, Earthquake Spectra, Vol. 15, No. 3 , Aug. 1999

Non-Patent Document 2: "Discussion on Reasonable Vibration Index Values - Relationship Between Vibration Indexes with DI Values" Nakamura, 2003, Seismological Engineering Proceedings of Civil Engineering Society

However, each proposal uses MMI as a vibration indicator. But it did not predict the degree of shaking of the earthquake. For structures with relatively long natural periods such as soil structures or wooden buildings built by methods such as piles of soil, it is necessary to consider that the degree of disaster caused by earthquakes is highly correlated with the speed of vibration.

Therefore, even if an earthquake in which an early warning is required to be an alarm is generated, a railway or the like that uses a large amount of soil structures such as piles may wish to consider the vibration speed for prediction, but it is not known whether it can be realized in the prior art.

In view of this, in the earthquake prediction apparatus of the first invention of the present invention, the MMI is used as the vibration index, and the vibration speed is considered in the initial stage of the vibration, and the degree of the earthquake shaking is predicted early.

The earthquake prediction device according to the first aspect of the present invention includes vertical acceleration acquisition units (10, S10), vertical speed calculation units (12, S14), and predicted value calculation units (16, S14). The vertical acceleration acquiring unit (10, S10) sequentially acquires the vertical acceleration information indicating the acceleration component of the vertical direction of the vibration from the sensor when the sensor detecting the vibration of the earthquake starts detecting the vibration.

The vertical speed calculation unit (12, S14) sequentially calculates the velocity component of the vertical direction of the earthquake based on the vertical acceleration information acquired by the vertical acceleration acquisition unit. The predicted value calculation unit (16, S14) calculates the maximum absolute value of the absolute value of the velocity component sequentially calculated by the vertical velocity calculation unit as the maximum velocity value (Vumax), and calculates the modified wheat using the following prediction formula. The predicted value of the earthquake shaking degree (MMIvp) expressed by the indicator value of the Garry earthquake intensity.

The predicted expression MMIvp = αvlog ₁₀ (Vumax) + βv. However, αv and βv are for the complex earthquakes that occurred in the past. The maximum value of the absolute value of the velocity component in the upper and lower directions of the vibration of each local vibration is taken as the explanatory variable (X), and the seismic shaking degree of the McGary earthquake intensity scale will be revised. The regression coefficient calculated by regression analysis after the index value is taken as the dependent variable (Y).

For example, regression analysis (Fig. 2) is performed using a database K-NET recorded in the past earthquake, and the result is Y = 3.67 log ₁₀ X + 3.72, so αv of the above prediction formula is 3.67, and βv is 3.72.

According to the proposal of Non-Patent Document 1 of Wald et al., when the absolute maximum value of the absolute value of the velocity of the earthquake is Vmax, the following calculation formula can be used to obtain the revised McGary earthquake intensity table. The indicator value of the degree of earthquake shaking (MMIv).

Calculated formula MMIv=αlog ₁₀ (Vmax)+β

In this calculation, α is 3.47 and β is 2.35.

If the predicted value (MMIvp) and the calculated value (MMIv) derived from the prediction formula and the calculation formula are compared, as shown in Fig. 5B, the predicted value (MMIvp) rises earlier than the calculated value (MMIv) at the beginning of the earthquake.

Therefore, with the earthquake prediction apparatus of the present invention, the MMI can be used as a vibration index, and the degree of shaking of the earthquake can be predicted early in the early stage of the earthquake. The earthquake prediction apparatus of the present invention predicts the degree of earthquake shaking in consideration of the speed of the vibration.

Therefore, the earthquake prediction device of the present invention is most suitable as a prediction device for predicting earthquakes such as railways having a large number of soil structures such as piles. Therefore, according to the earthquake prediction apparatus of the present invention, the train can be stopped early by the automatic train stop device at the time of the earthquake, and the accident such as the train overturning can be suppressed by suppressing the collapse of the pile.

Since the earthquake prediction apparatus of the present invention uses the MMI as a vibration index, it can perform an internationally common earthquake prediction. Next, as the second of the present invention In the earthquake prediction device of the first aspect, the adjustment coefficient setting unit (22) for adjusting the adjustment coefficient (γv) can be added to the earthquake prediction device of the first aspect, and the following prediction formula for accelerating the adjustment coefficient (γv) can be used as the prediction expression.

The predicted expression is MMIvp = αvlog ₁₀ (Vumax) + βv + γv.

In the case where the earthquake prediction device of the present invention is used to predict earthquake occurrence and an alarm is issued, it is expected that the user may have the following two requirements, for example.

The first is that even if the prediction is not accurate, it is okay to predict the earthquake that needs to be guarded. Regardless of whether the earthquake that needs to be vigilant does occur, it will also be handled as an alarm, that is, to improve the success rate of the alarm.

The other is that it is okay to have an alarm when there is an earthquake that requires vigilance. I hope that there will be no alarm when there is no earthquake that needs to be vigilant, that is, to reduce the air-vibration alarm rate as the main consideration. Here, the air vibration alarm refers to an alarm that is excessively sensitive to small shaking.

Therefore, in the earthquake prediction apparatus of the present invention, γv is added to the prediction formula to adjust the magnitude of the calculated predicted value (MMIvp), and the above two requirements can be matched. For example, when the alarm reference value is set to 5.5 steps of MMI and γv is set to -1, as shown in Fig. 8, the air-vibration alarm rate is close to 0%, and conversely, when γv is set to 1, The alert success rate is close to 100%.

That is to say, when γv is set to 1, if an earthquake requiring an alert is predicted to occur, an alarm will be issued regardless of whether or not an earthquake requiring an alert actually occurs.

On the other hand, when γv is set to -1, there is a case where an alarm is not generated when an earthquake requiring an alarm occurs, but an alarm is not issued when an earthquake requiring an alarm does not occur.

Therefore, with the earthquake prediction device of the present invention, in addition to the effect of the earthquake prediction device of the first aspect of the present invention, it is possible to perform prediction in response to user requirements. Next, the earthquake prediction apparatus according to the third aspect of the present invention may include an alarm unit (18, S22 to S24), and compare the predicted value (MMIvp) calculated by the predicted value calculation unit with a preset alarm reference value, and the predicted value (MMIvp) • An alarm is issued when the alarm reference value is exceeded.

This earthquake prediction apparatus performs an alarm only when the predicted value (MMIvp) exceeds a predetermined alarm reference. Therefore, it is possible to suppress an alarm when an earthquake that does not require an alarm is generated.

Further, the earthquake prediction apparatus according to the fourth aspect of the present invention may include a earthquake occurrence determination unit (20) that determines the occurrence of an earthquake by the presence or absence of the vibration, and the alarm unit performs an alarm when the earthquake occurrence determination unit determines that the earthquake has occurred.

In addition, the symbols in the parentheses of the above-mentioned respective parts and the like indicate an example of the correspondence relationship with the functional squares and the like which are described in the embodiments below, and the present invention is not limited to the functional squares indicated by the symbols in the parentheses of the respective parts and the like.

1‧‧‧ Earthquake prediction device

1a‧‧‧ROM

3‧‧‧Acceleration sensor device

5‧‧‧External alarm device

10‧‧‧Acceleration Acquisition Department

12‧‧‧Upper and lower speed calculation unit

14‧‧‧Speed Recording Department

16‧‧‧predicted value calculation unit

18‧‧‧1st Alarm Department

20‧‧‧ Earthquake Judgment Department

20a‧‧‧mark memory area

22‧‧‧Full coefficient setting department

24‧‧‧General Earthquake Judgment Department

26‧‧‧2nd Alarm Department

30‧‧‧Up and down acceleration sensor

32‧‧‧ East-West Acceleration Sensor

34‧‧‧North-South acceleration sensor

A‧‧‧ Earthquake alarm processing

Fig. 1 is a block diagram showing the respective functions of the earthquake prediction device of the first embodiment.

The second graph is an exponential function graph in which the horizontal axis is the velocity (unit kine) and the heald axis is the MMI index value. It is the largest among the absolute values of the velocity components in the vertical direction of the vibration of each earthquake. The horizontal axis coordinates are used, and the degree of shaking of each earthquake is represented by the MMI index value as a vertical axis coordinate.

Figure 3 shows the earthquakes that occurred in the past to show the degree of shaking of each earthquake. A table in which the calculated value (MMIv) and the predicted value (MMIvp) are classified based on the order of 5.5 or more, respectively, and the classified data is displayed.

Fig. 4 shows the time difference between the predicted value (MMIvp) reaching 5.5 order and the calculated value (MMIv) reaching 5.5 order, which shows the calculated values (MMIv) and predicted values (MMIvp) in the past. , a table showing the classified data.

Figure 5A is a graph of the time-dependent changes in predicted values (MMIvp) and calculated values (MMIv) for the 2011 Pacific Northwest Pacific Earthquake and shows the change from the start to the end of the earthquake detection.

Figure 5B is a graph showing the time-dependent change of the predicted value (MMIvp) and the calculated value (MMIv) in the Northeast Pacific Ocean during the 2011 earthquake. In order to easily change the read value, the interval of 10 to 40 seconds in Figure 5A is enlarged. display.

Fig. 6 is a flowchart showing the earthquake alarm processing performed by the earthquake prediction device of the first embodiment.

Fig. 7 is a block diagram showing, in a block, the respective functions of the earthquake prediction device of the second embodiment.

Fig. 8 is a graph showing changes in the alarm success rate and the air vibration alarm rate in the case where the adjustment coefficient (γv) is adjusted.

Fig. 9 is a block diagram showing, in block, the respective functions of the earthquake prediction device of another embodiment.

Fig. 10 is a flow chart showing the earthquake alarm processing performed by the earthquake prediction device of another embodiment.

The embodiments of the present invention will be described below in conjunction with the drawings.

(first embodiment) 1. Earthquake prediction device 1

The earthquake prediction device of the first embodiment will be described using FIG. The following paragraphs describing the first embodiment will be referred to as the present embodiment.

The earthquake prediction device 1 of the present embodiment is a computer device including a CPU, a ROM 1a, a RAM, and the like. The CPU and RAM are not shown in Figure 1. The earthquake prediction device 1 is connected to the acceleration sensor device 3 and the external alarm device 5.

The acceleration sensor device 3 includes three acceleration sensors (up and down acceleration sensors 30 and east-west acceleration sensors 32) for detecting acceleration components in three orthogonal directions (upper, lower, east, and north). , north-south acceleration sensor 34).

In the present embodiment, the observation points are dispersedly set in the region of the warning earthquake, and each of the observation points is provided with the earthquake prediction device 1 and the acceleration sensor device 3. When the seismic wave reaches the observation point, each of the sensors 30 to 34 of the acceleration sensor device 3 starts detecting the vibration acceleration component of each observation point, and starts outputting an analog signal representing each acceleration component.

The external alarm device 5 is installed at a place away from each observation point, and is communicably connected to the plurality of earthquake prediction devices 1 provided at the respective observation points via a public line. When the external alarm device 5 receives the alarm signal of any of the earthquake prediction devices 1, it outputs an alarm sound and performs an alarm operation for notifying the alarm information and the like.

On the other hand, when the external alarm device 5 is interlocked with the train control device, for example, the alarm operation can be performed as soon as the alarm signal is received, and an instruction to stop the train can be output to the train control device.

As shown in FIG. 1, the earthquake prediction device 1 includes an acceleration acquisition unit 10, a vertical speed calculation unit 12, a speed recording unit 14, a predicted value calculation unit 16, a first alarm unit 18, and a earthquake occurrence determination unit 20. The functions of the respective units 10 to 20 are realized by the earthquake prediction device 1 executing the earthquake alarm processing A described later stored in the ROM 1a.

The acceleration acquiring unit 10 sequentially inputs the analog signals indicating the acceleration components of the three directions (east, north, south, and up and down) outputted by the respective sensors 30 to 34 of the acceleration sensor device 3 for each predetermined The sampling period samples these analog signals.

Then, the acceleration acquisition unit 10 outputs a digital signal obtained by sampling the analog signal indicating the acceleration component in the vertical direction of the earthquake to the vertical velocity calculation unit 12 and the earthquake occurrence determination unit 20.

The acceleration acquisition unit 10 sequentially outputs a digital signal obtained by sampling an analog signal indicating an acceleration component in the east-west direction of the earthquake and an acceleration component in the north and south to the earthquake occurrence determination unit 20. In the present embodiment, the sampling period is set to 100 Hz, but the present invention is not limited thereto (the acceleration acquiring unit 10 may be disposed in the acceleration sensor device 3, and the digital signal may be transmitted from the acceleration sensor device 3 to the earthquake prediction. Device). When the digital signal indicating the acceleration component in the vertical direction of the earthquake from the acceleration acquiring unit 10 is input for each sampling period, the vertical component speed calculating unit 12 integrates the acceleration component with the sampling time (1/100 second), and sequentially calculates the earthquake up and down. The processing of the velocity component of the direction (in kine).

The speed recording unit 14 stores information on the speed component (hereinafter referred to as "up and down speed information") when the vertical velocity calculation unit 12 calculates the velocity component in the vertical direction of the earthquake.

When the vertical speed calculation unit 12 calculates the velocity component in the vertical direction of the earthquake, the predicted value calculation unit 16 uses the maximum value of the absolute value of the velocity component in the vertical direction extracted from the vertical velocity information stored in the velocity recording unit 14 . It is the maximum speed (Vumax), and the predicted value (MMIvp) indicating the degree of earthquake shaking in MMI is calculated in order based on the prediction formula described later.

When the earthquake occurrence determination unit 20 determines that the predicted value (MMIvp) calculated by the predicted value calculation unit 16 is greater than a predetermined alarm reference value (5.5 steps in the MMI), the first alarm unit 18 outputs the earthquake value determination unit 20. The alarm signal is sent to the external alarm device 5.

The earthquake occurrence determination unit 20 includes a flag memory area 20a. The flag memory field 20a is used to store flag information, and the flag information is used in the earthquake alarm processing A (refer to FIG. 6) described later, and is used to display whether the observation point detects an earthquake, that is, whether an earthquake has occurred now.

When the seismic generation determining unit 20 receives the digital signal indicating the acceleration component in the orthogonal three directions of the earthquake from the acceleration acquiring unit 10 for each sampling period, the seismic generating unit 20 combines the vectors of the acceleration components in the three directions and obtains the absolute value of the vector. value.

Then, in order to determine whether or not the earthquake has occurred, when the absolute value of the acceleration exceeds the predetermined earthquake occurrence reference value, the earthquake occurrence determining unit 20 sets the flag information stored in the flag memory area 20a to "1".

On the other hand, when the absolute value of the acceleration is equal to or less than the predetermined earthquake occurrence reference value, the earthquake occurrence determining unit 20 sets the flag information stored in the flag memory area 20a to "0". Then, the earthquake occurrence determining unit 20 outputs the flag information stored in the flag memory area 20a to the first alarm unit 18.

2. About the calculation method of MMIvp

Next, the following prediction formula used in the present embodiment will be described.

Predictive formula MMIvp=αvlog ₁₀ (Vumax)+βv

This predictive formula is used to find the predicted value (MMIvp) that is used to revise the magnitude of the earthquake to correct the magnitude of the Megali earthquake.

Vumax is the absolute maximum value among the absolute values among the velocity components stored in the vertical direction of the vibration of the speed recording unit 14. As described above, when the vertical acceleration sensor 30 starts detecting the vibration, the acceleration acquisition unit 10 sequentially inputs an analog signal indicating the acceleration component of the vibration vertical direction output from the vertical acceleration sensor 30.

Then, the vertical speed calculating unit 12 sequentially calculates the velocity components in the vertical direction of the vibration, and stores the calculated results in the speed recording unit 14 in order. Therefore, when the predicted value calculation unit 16 calculates the predicted value (MMIvp) using the above-described prediction formula, the maximum speed value (Vumax) is obtained from the speed recording unit 14.

On the other hand, αv and βv are coefficient values calculated in advance using waveform data recorded by the seismic observation network K-NET of the Institute of Disaster Prevention Science and Technology. If the absolute value (kine) and MMI index value of the velocity components in the vertical direction of each recording waveform are obtained from the 2323 recording waveform data recorded by K-NET in the past 13 earthquakes, they are respectively plotted as the horizontal axis. And the vertical axis is drawn on a semi-logarithmic curve, and the relationship as shown in Fig. 2 is displayed.

Αv and βv are regression variables calculated by using the maximum value of the absolute value of the velocity component in the vertical direction of Fig. 2 as the explanatory variable (X) and the index value of the MMI as the dependent variable (Y). coefficient.

When the regression analysis was performed using the vibration data of the earthquake recorded in this K-NET, the result was Y = 3.67 log ₁₀ X + 3.72, so αv of the above prediction formula was 3.67, and βv was 3.72.

In order to express the degree of sway of each earthquake by the index value of the MMI, the index value (hereinafter referred to as "calculated value (MMIv)") is calculated using the calculation formula proposed by Non-Patent Document 1 of Wald et al.

Calculated formula MMIv=αlog ₁₀ (Vmax)+β

Here, Vmax is the absolute value of the maximum speed of the vibration. And α is 3.47 and β is 2.35.

Next, the seismic waveform data recorded in K-NET and the above prediction formula and calculation formula are used to simulate the change of the predicted value (MMIvp) and the calculated value (MMIv) with respect to time, and the results of the simulation are compared. The comparison result will be described below.

As shown in Fig. 3, in the seismic waveform data of 2323 cases to be discussed, the predicted value (MMIvp) and the calculated value (MMIv) are both MMI index values M indicating 5.5 or more. example.

In the above simulation, there are 173 cases in which the predicted value (MMIvp) reaches the 5.5th order of the MMI value value before the calculated value (MMIv). On the contrary, there are 126 cases in which the calculated value (MMIv) arrives first.

Then, further review the seismic waveform data of the above 299 cases. As shown in Fig. 4, the predicted value (MMIvp) is 5.5 steps higher than the calculated value (MMIv) in the range of 0 seconds or more to less than 2 seconds. There are 92 cases of seismic waveform data.

On average, the predicted value (MMIvp) reaches the 5.5th order of the revised McGary earthquake intensity about 4 seconds earlier than the calculated value (MMIv). Here, the predicted value (MMIvp) and the calculated value (MMIv) are the 5.5th order of the MMI value. Seismic waveform. If we observe the 9.5-order seismic waveform with the maximum intensity of the MMI value in the Northeast Pacific Pacific Earthquake in 2011, as shown in Figure 5B, the predicted value (MMIvp) is 8 times earlier than the calculated value (MMIv) in the early stage of the earthquake. The second reaches the 5.5th order of the MMI value.

On the other hand, in such an earthquake, if the earthquake occurs for more than 100 seconds, as shown in Fig. 5A, the predicted value (MMIvp) and the calculated value (MMIv) will display substantially the same value. That is to say, the earthquake prediction apparatus 1 of the present embodiment can use the MMI as a vibration index, and predict whether or not the degree of shaking of the alarm is required early in the early stage of the earthquake.

3. Earthquake alarm processing

Next, the earthquake warning processing A performed by the earthquake prediction device 1 of the present embodiment will be described using FIG.

The earthquake alarm processing A of the present embodiment starts after the power switch of the earthquake prediction device 1 is turned on, and thereafter, the processing is repeated every sampling period until the power switch is turned off.

In this earthquake alarm processing A, the acceleration acquisition processing of S10 is first executed. In the processing performed by the acceleration acquiring unit 10 of S10, an analog signal indicating the acceleration component of the vibration 3 direction (east, north, south, and up) detected by the acceleration sensor device 3 is sequentially input from the acceleration sensor device 3, and Sampling is performed.

Then, in S10, the digital signal indicating the acceleration component of the sample in the vertical direction of the vibration is output to the vertical velocity calculation unit 12 and the earthquake occurrence determination unit 20, and the digital signal indicating the acceleration component in the east-west direction and the acceleration component in the north-south direction is output. The earthquake occurrence determining unit 20 is used.

Next, the calculation of the speed of S12 and the calculation of MMIvp is performed. In the process performed by the vertical velocity calculation unit 12 of S12, the velocity component in the vertical direction of the vibration is calculated based on the acceleration component in the vertical direction of the vibration indicated by the digital signal from the acceleration acquisition unit 10.

Further, in the process performed by the predicted value calculation unit 16 in S12, the maximum speed value (Vumax) of the maximum value of the absolute value of the velocity component in the vertical direction is extracted from the vertical velocity information recorded in the speed recording unit 14, and the predicted value is calculated. (MMIvp).

Then, in the process performed by the earthquake occurrence determination unit 20 of S14, the acceleration acquisition unit 10 converts the acceleration component of the three-direction vibration of the digital signal to calculate the acceleration of the vibration of the observation point.

Next, the process of S16 is performed. A process of determining whether or not an earthquake has occurred is performed in S16. Specifically, in the processing performed by the first alarm unit 18 of S16, it is determined whether the flag stored in the flag memory area 20a is "0" indicating that the earthquake occurred or the normal state in which the earthquake did not occur. 1".

If it is determined in S16 that the flag is "0", that is, the "normal state" (S16: YES), the processing of S18 is performed. If it is determined in S16 that the flag is "1", that is, "earthquake is occurring" (S16: NO), the processing of S22 is performed.

At S18, for the acceleration of the vibration of the observation point, a process of determining whether or not the absolute value of the acceleration is larger than the aforementioned earthquake occurrence reference value is performed. The step of S18 is performed by the earthquake occurrence determining unit 20.

In S18, when the absolute value of the acceleration of the earthquake is larger than the earthquake occurrence reference value, that is, in the case where the earthquake occurs (S18: YES), The process of changing the flag stored in the flag memory area 20a from "0" to "1" is performed (S20). Thereafter, the earthquake alarm processing A ends, and the processing of S10 or lower is performed again.

On the other hand, when the absolute value of the acceleration of the earthquake is smaller than the earthquake occurrence reference value, that is, when the earthquake does not occur (S18: NO), the earthquake alarm processing A is immediately completed, and the processing of S10 or lower is performed again.

Next, the processing of S22 performed when the flag is determined to be "1" in S16, that is, when "the earthquake is occurring" (S16: NO) is described. S22 is a process performed by the first alarm unit 18. This process determines whether or not the predicted value (MMIvp) calculated in S12 is equal to or greater than the alarm reference value, that is, whether it is 5.5 or more of the MMI.

In S22, if it is determined that the predicted value (MMIvp) is larger than the alarm reference value, as described above, on average, four seconds before the shaking of 5.5 or more of the MMI is actually generated at the observation point provided by the earthquake prediction device 1.

Therefore, when it is determined that the predicted value (MMIvp) MMI is 5.5 or more (S22: YES), the process of S24 is performed, and the first alarm unit 18 transmits an alarm signal to the external alarm device 5. Then, after S24, the processing of S27 is performed.

On the other hand, if it is determined in S22 that the predicted value (MMIvp) is less than 5.5 steps of the MMI (S22: YES), the processing of S27 is performed next. In S27, in contrast to S18, a process of determining whether or not the magnitude of the acceleration of the vibration of the observation point is smaller than a predetermined earthquake occurrence reference value is performed.

This S27 is performed by the earthquake occurrence determining unit 20. In this S27, as in S18, the absolute acceleration of the acceleration is determined for the acceleration of the earthquake at the observation point. Whether the value is below the aforementioned earthquake occurrence reference value.

When the absolute value of the acceleration of the vibration is equal to or less than the reference value (S27: YES), the process of changing the flag stored in the flag memory area 20a from "1" to "0" is performed (S28). ). Thereafter, the earthquake alarm processing A ends, and the processing of S10 or lower is performed again.

On the other hand, when the magnitude of the acceleration of the earthquake is larger than the earthquake occurrence reference value (S27: NO), the earthquake alarm processing A is immediately completed, and the processing of S10 or lower is performed again.

4. The characteristic effect of the earthquake prediction device of this embodiment

As described above, if the vibration prediction value (MMIvp) and the calculated value (MMIv) of the earthquake occurring in the past are compared, as shown in FIG. 5B, the predicted value (MMIvp) is earlier than the calculated value (MMIv) in the early stage of the earthquake. The alarm reference value is reached.

Therefore, by using the earthquake prediction apparatus 1 of the present embodiment, it is possible to predict the occurrence of an earthquake requiring an alarm early in the early stage of the earthquake using the MMI as a vibration index. Further, the earthquake prediction apparatus 1 of the present embodiment considers the speed of the vibration to predict the degree of shaking of the earthquake.

Therefore, the earthquake prediction device 1 of the present embodiment is most suitable as a prediction device for predicting earthquakes such as railways having a large number of soil structures such as piles. In other words, when the earthquake prediction device 1 of the present embodiment predicts an earthquake-producing device such as a railway having a large number of soil structures such as piles, the train can be stopped early by using the automatic train stop device during the earthquake occurrence. The collapse of the pile of soil caused accidents such as train overturning.

In addition, it is also possible to stop the elevator or inform people of the occurrence of an earthquake through a television or the like. Moreover, the earthquake prediction apparatus 1 of this embodiment is used because of MMI early predicts the occurrence of earthquakes that require an alarm, so it can be used for internationally common earthquake prediction.

In the earthquake prediction device 1 of the present embodiment, the alarm is performed only when the predicted value (MMIvp) exceeds the predetermined earthquake occurrence reference value (S22→S24). Therefore, it is possible to suppress the occurrence of an alarm when an earthquake that does not require an alarm occurs. .

(Second embodiment)

Next, a second embodiment of the present invention will be described.

In the present embodiment, only points different from the first embodiment will be described. In the following paragraphs describing the second embodiment, the second embodiment will be described as the present embodiment.

1. Earthquake prediction device 1

The earthquake prediction device 1 of the present embodiment is different from the earthquake prediction device 1 of the first embodiment in that the adjustment coefficient setting unit 22 is provided as shown in FIG.

In the present embodiment, the adjustment value γv is added to the prediction expression of the predicted value (MMIvp) used by the predicted value calculation unit 16 , which is different from the first embodiment.

Predictive formula MMIvp=αvlog ₁₀ (Vumax)+βv+γv

In the present embodiment, γv can be adjusted between -1 and 1, and the adjustment coefficient setting unit 22 can adjust the γv value by artificially changing the amount of rotation by using, for example, a rotary adjustment knob.

The predicted value calculation unit 16 adds the γv to the predicted value (MMIvp) in the prediction expression using the adjustment value set by the adjustment coefficient setting unit 22. In S22 of the earthquake alarm processing A performed by the earthquake prediction device 1 of the present embodiment, The calculation of the measured value (MMIvp) is also carried out using the prediction formula added to the above γv.

2. About the adjustment value γv

Next, the alarm success rate and the air vibration alarm rate will be described using FIG. This alarm success rate and air vibration alarm rate are calculated using the vibration data of the earthquake recorded in K-NET.

The alarm success rate is a ratio in which the calculated value (MMIv) is 5.5 or more, and the predicted value (MMIvp) is 5.5 or more. The air-vibration alarm rate is the ratio of the earthquake whose calculated value (MMIv) is less than 5.5 among the total number of predicted values (MMIvp) of 5.5 or more.

As shown in Fig. 8, the alarm success rate is higher as γv is closer to 1, and when γv is 1, there is almost 100% alarm success rate. Conversely, the alarm success rate will be lower as γv is closer to -1, and the alarm success rate is about 40% when γv is -1.

On the other hand, the air-vibration alarm rate is lower as γv is closer to -1, and the vacancy alarm rate is almost 0% when γv is -1. On the contrary, the air vibration alarm rate will be higher as γv is closer to 1, and the alarm success rate is about 40% when γv is 1.

3. The characteristic effect of the earthquake prediction device of this embodiment

The earthquake prediction device 1 of the present embodiment has an effect of achieving the earthquake prediction device 1 of the first embodiment, and the following effects can be achieved.

When the earthquake prediction apparatus 1 of the present embodiment is used to predict earthquake occurrence early and an alarm is issued, it is expected that the user may have the following two requirements, for example. The first is that even if the prediction is not accurate, it is okay to predict the earthquake that needs to be guarded. Regardless of whether the earthquake that needs to be vigilant does occur, it will also be handled as an alarm, that is, to improve the success rate of the alarm.

The other is that there is no warning even if an earthquake that requires vigilance occurs. It doesn't matter if you report the situation. I hope that there will be no alarm when there is no earthquake that needs to be guarded. That is to say, the main reason is to reduce the air-vibration alarm rate.

Therefore, in the earthquake prediction device 1 of the present embodiment, γv is added to the prediction formula to adjust the magnitude of the calculated predicted value (MMIvp), and the above two requirements can be matched. For example, when the alarm reference value is set to 5.5 steps of MMI and γv is set to -1, as shown in Fig. 8, the air-vibration alarm rate is close to 0%, and conversely, when γv is set to 1, The alert success rate is close to 100%.

That is to say, when γv is set to 1, if an earthquake requiring an alert is predicted to occur, an alarm will be issued regardless of whether or not an earthquake requiring an alert actually occurs. On the other hand, when γv is set to -1, there is a case where an alarm is not generated when an earthquake requiring an alarm occurs, but an alarm is not issued when an earthquake requiring an alarm does not occur.

Therefore, by using the earthquake prediction device 1 of the present embodiment, it is possible to perform prediction in response to the request of the user.

(correspondence relationship)

The information on the acceleration component in the vertical direction of the vibration indicated by the analog signal output from the vertical acceleration sensor 30 of the above-described embodiment corresponds to an example of the vertical acceleration information of the present invention.

The processing performed by the acceleration acquiring unit 10 in the processing of S10 of the above-described embodiment corresponds to an example of the vertical acceleration acquiring unit described in the patent application. The process performed by the vertical acceleration calculation unit 12 in the process of the above-described embodiment S14 corresponds to an example of the vertical acceleration calculation unit described in the patent application.

In the processing of S14 of the above-described embodiment, the predicted value calculation unit 16 The processing of the line corresponds to an example of the predicted value calculation unit described in the patent application. In the processing of S22 to S24 of the above-described embodiment, the first alarm unit 18 sends an alarm signal to the external alarm device 5, which corresponds to an example of the alarm processing performed by the alarm unit described in the patent application.

(other implementation types)

In the above-described embodiment, the acceleration sensor device 3 and the earthquake prediction device 1 are described as individual devices, but the acceleration sensor device 3 may be incorporated into the earthquake prediction device 1.

In the above-described embodiment, the external alarm device 5 is a device that communicates with the earthquake prediction device 1 through a public line. However, the external alarm device 5 may be an alarm device that can provide an alarm sound. As shown in FIG. 9, the earthquake prediction device 1 may include a general earthquake determination unit 24 and a second alarm unit 26 that determine the earthquake and alert by a known determination method.

In this case, the second alarm unit 26 performs a process of sending an alarm to the external alarm device 5 after the general earthquake determination unit 24 determines that the earthquake has occurred. Therefore, in the earthquake prediction device 1 of the present embodiment, when either of the first alarm unit 18 or the second alarm unit 26 determines that an earthquake has occurred, the external alarm device 5 issues an alarm.

Further, in this case, the adjustment coefficient setting unit 22 may be provided, or the adjustment coefficient setting unit 22 may not be provided. When the general earthquake determination unit 24 and the second alarm unit 26 are provided, as shown in FIG. 10, the processes of S25 and S26 can be performed between S24 and S27.

In this case, in S25, it is determined by a known method whether or not an earthquake has occurred. If it is determined that an earthquake has occurred (S25: YES), a process of issuing a second alarm different from the early warning of the above-described embodiment is performed in S26.

Further, the functions 10 to 26 of the respective units constituting the earthquake prediction device 1 of the present embodiment can be realized by a computer stored in the ROM 1a on a computer that connects the acceleration sensor device 1 and the external alarm device 5. This program can be executed by loading the ROM1a or the spare RAM into the computer, or by loading the computer through the network.

This program can be stored in all types of recording media that can be read by the computer. The recording medium includes a portable semiconductor memory such as a USB flash drive, a memory card (registered trademark), and the like.

The present invention can be created in accordance with the same technical idea as the invention described in the patent application, and is not limited to the above-described embodiment.

1‧‧‧ Earthquake prediction device

1a‧‧‧ROM

3‧‧‧Acceleration sensor device

5‧‧‧External alarm device

10‧‧‧Acceleration Acquisition Department

12‧‧‧Upper and lower speed calculation unit

14‧‧‧Speed Recording Department

16‧‧‧predicted value calculation unit

18‧‧‧1st Alarm Department

20‧‧‧ Earthquake Judgment Department

20a‧‧‧mark memory area

30‧‧‧Up and down acceleration sensor

32‧‧‧ East-West Acceleration Sensor

34‧‧‧North-South acceleration sensor

Claims (4)

An earthquake prediction apparatus includes: an up-and-down acceleration acquisition unit (10, S10), and when a sensor that detects a vibration of an earthquake starts detecting a vibration, sequentially obtaining an acceleration component indicating an up-and-down direction of the vibration from the sensor Acceleration information; the vertical speed calculation unit (12, S12) sequentially calculates the velocity component of the vertical direction of the vibration based on the vertical acceleration information acquired by the vertical acceleration acquisition unit; and the predicted value calculation unit (16, S12) The maximum absolute value of the absolute values of the velocity components sequentially calculated by the vertical speed calculating unit is used as the maximum speed value (Vumax), and the earthquake expressed by the index value of the revised Megali seismic intensity is calculated using the following prediction formula. The predicted value of the degree of shaking (MMIvp), the predicted expression MMIvp = αvlog ₁₀ (Vumax) + βv, where αv and βv are regression coefficients previously calculated by regression analysis. The earthquake prediction apparatus according to claim 1, further comprising: an adjustment coefficient setting unit (22) for adjusting an adjustment coefficient (γv), wherein the prediction value calculation unit adds the adjustment coefficient (γv) The predicted value (MMIvp) is calculated by the following prediction formula, and the prediction formula MMIvp = αvlog ₁₀ (Vumax) + βv + γv. The earthquake prediction device according to claim 1 or 2, further comprising: an alarm unit (18, S22 to S24) that compares the predicted value (MMIvp) calculated by the predicted value calculation unit with a preset alarm The reference value is an alarm when the predicted value (MMIvp) exceeds the alarm reference value. The earthquake prediction device according to claim 3, further comprising: an earthquake occurrence determination unit (20) that determines the occurrence of the earthquake by the presence or absence of a vibration, wherein the alarm portion determines that the earthquake occurs when the earthquake occurrence determination unit determines Alert.