JPH10123258A - Method for measuring magnitude of seismic motion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify and stabilize processing operation by performing SI value calculating operation repeatedly while shifting the range of a time series data by a second set time. SOLUTION: Calculation is started at an appropriate moment of time R irrespective of an earthquake generating moment of time S or a settling moment of time E. An SI value is calculated, at first, using a time series data in the range of time T from the moment of time R to a moment of time T, from a moment of time Δt to a moment of time T+Δt upon elapsing the time Δt after the moment of time R, and from a moment of time 2Δt to a moment of time T+2Δt upon elapsing another time Δt. Similarly, SI value is calculated every time when the time Δt elapses using a time series data in the range of time T starting from that moment of time. Since a similar processing can be continued from an appropriate moment of time, e.g. a moment of time for recording an acceleration data, irrespective of occurrence or ending of earthquake without requiring any switching of operation mode, the operation is not complicated and a stable operation can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic intensity measurement method used for a control seismometer or the like.

[0002]

2. Description of the Related Art In the event of an earthquake, there is a control seismometer as a device for controlling various systems according to the intensity of the earthquake to prevent the spread of damage and the occurrence of secondary disasters.
2. Description of the Related Art A control seismometer is used in various facilities such as transportation, city gas, electric power, and water supply by being incorporated in an automatic emergency stop device at the time of a large earthquake.

In such a control seismometer, a method of measuring the SI value as a measure of the intensity of earthquake motion has been proposed and implemented in order to perform control having a high correlation with the degree of damage to the structure. (For example, Japanese Patent Application Laid-Open No. 62-12884
JP, JP-A-62-12884, JP-A-62-12884
No. 12884, Japanese Patent Application Laid-Open No. Sho 62-12885, Japanese Patent Application Laid-Open No. Sho 62-12886, Japanese Patent Application Laid-Open No. 6-214040
See JP-A-8-36062 and JP-A-8-36062. )

In such a method, the SI value is obtained by inputting an acceleration waveform of a seismic motion measured by a seismometer into an arithmetic unit that satisfies the equation of motion of a one-degree-of-freedom vibration system to obtain a speed response, and obtaining a maximum value of the speed response. , Ie, the velocity response spectrum Sv, and is calculated by performing a predetermined calculation, and these are performed by real-time calculation.

A conventional real-time calculation method will be described with reference to FIG. In the figure, the upper part shows an example of time series data of the acceleration of the earthquake. In this method, a threshold value is set for the acceleration as a trigger for earthquake occurrence and a threshold value for a trigger for earthquake convergence. , The operation mode of the arithmetic processing device is switched to perform predetermined arithmetic processing. That is, when the acceleration measured by the seismometer exceeds the earthquake occurrence trigger, the arithmetic processing device is switched to the calculation mode to start the calculation, and when the earthquake convergence trigger is exceeded, the calculation ends, and the arithmetic processing device is set to the monitoring mode. Switch to.

The calculation in the calculation mode is performed as shown in the lower part of the figure. That is, after the acceleration exceeds the earthquake trigger and the arithmetic processing device enters the calculation mode, every time a certain time interval Δt (second) elapses, it goes back to the time immediately after the earthquake, that is, t = 0. The calculation is performed based on the acceleration data from the time point to the current time point. For example, at the time point t = Δt when Δt has elapsed from the time point t = 0 when the calculation is started, the calculation is performed based on the acceleration data from the time point t = 0 to the time point Δt,
Further, at time t = 2Δt after Δt has elapsed, calculation is performed based on acceleration data for a time 2Δt from time t = 0 to 2Δt. In this way, the calculation is performed every time a certain time interval Δt (second) elapses, and when the earthquake convergence trigger is exceeded, the SI value is calculated from the acceleration data of the time T from the time t = 0 to the time when the trigger is exceeded. I do.

[0007]

In the conventional real-time calculation method as described above, an earthquake trigger and an earthquake convergence trigger are set, and the operation of a different mode between the time of the earthquake and the normal time is performed by the arithmetic processing device. And the calculation is always retroactive to the beginning of the earthquake,
The arithmetic processing unit is performing a very complicated operation. Further, in order to calculate the SI value of one earthquake, it is necessary to store all the earthquake data from the occurrence to the end in a memory, so that a large amount of memory is required. Therefore, an object of the present invention is to solve such a problem.

[0008]

In order to solve the above-mentioned problems, according to the present invention, acceleration data continuously output from a seismograph is sequentially recorded, and a first set time in the recorded data is recorded. The SI value is calculated from the time series data of the range, and the SI value calculation operation is repeatedly performed by shifting the range of the time series data by the second set time every time the second set time elapses. A method for measuring the intensity of earthquake motion is proposed.

Further, according to the present invention, in the above configuration, S
It is proposed that the calculation of the I value be performed on the acceleration signals of the seismic motion components in a plurality of directions. The acceleration signals of the seismic motion components in the plurality of directions are obtained from seismometers installed corresponding to the respective directions, or the acceleration signals of at least two of the horizontal two components and the vertical components detected by the seismometers. Is obtained by vector synthesis.

According to the present invention described above, the arithmetic processing device comprises:
Regardless of the occurrence or termination of an earthquake, similar calculation processing can be continued from an appropriate point in time, such as the point in time when acceleration data is recorded, and there is no need to switch operation modes. Operation is obtained. Further, since the range of the time-series data used for calculating the SI value is the range of the second set time, it is possible to reduce the memory for storing the data at the time of the arithmetic processing and to reduce the calculation load.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view conceptually showing a real-time calculation method according to the present invention, and FIG. 2 is a system diagram conceptually showing an example of a configuration of a control seismometer to which the method of the present invention is applied. First, in FIG. 2, reference numeral 1 denotes a seismometer. The seismometer 1 has an acceleration detector 2a corresponding to a plurality of directions, for example, two horizontal directions orthogonal to each other, and three directions obtained by adding the vertical direction to the two horizontal directions. , 2b. These detectors 2a and 2b are installed so as to measure the accelerations of the north-south direction and the east-west direction components, for example, as in the conventional case. The accelerations detected by the acceleration detectors 2a and 2b are input to an arithmetic processing unit 3, where the accelerations are sequentially recorded by an appropriate recording unit, and are processed by a predetermined arithmetic processing described later. A value is calculated. Reference numeral 4 denotes a control unit. The control unit 4 controls various systems based on the SI value calculated by the arithmetic processing unit 3 and automatically operates when an earthquake that is likely to damage the structure occurs. Take safety measures such as shutting down.

Next, the real-time calculation method of the SI value in the arithmetic processing unit 3 as the arithmetic processing will be described with reference to FIG. In the figure, the upper part shows an example of time-series data of acceleration sequentially output from the acceleration detecting unit 2. Within the range of the time-series data, an earthquake occurs at a point S indicated by an arrow and converges at a point E. doing. As described above, in the conventional real-time calculation method, the calculation is started by determining the time point S by the earthquake occurrence trigger, and the calculation is completed by determining the time point E by the earthquake convergence trigger. However, in the real-time calculation method of the present invention, the calculation is continued regardless of these time points S and E. That is, in the present invention, the calculation described below is started from an appropriate time point R that is not related to these time points S and E, and this calculation is continued. The time point R may be a time point when the recording of the acceleration is started, or may be a suitable time point thereafter.

First, the calculation of the first SI value after the start of the calculation is as follows.
Time series data of acceleration from time R (t = 0) to time (t = T) after a lapse of T time, that is, time range of time T from time R (t = 0) to time (t = T) This is performed using sequence data. This time T corresponds to the above-described first set time. When performing such a calculation, the arithmetic processing device 3 stores the time-series data in the above range in the recorded acceleration data in the memory.

Next, when the set time Δt has elapsed from the time point R, the acceleration time series data from the time point (t = Δt) to the time point (t = T + Δt) after the elapse of T time, that is, the time point (t = Δt ) To time (t = T + Δt), the SI value is calculated using the time series data in the range of time T. This time Δt corresponds to the above-mentioned second set time.

Next, when the time Δt further elapses, the time T (t = 2Δt) elapses from the time (t = 2Δt).
The SI value is calculated using the time-series data of the acceleration up to (T + 2Δt), that is, the time-series data in the range of the time T from the time (t = 2Δt) to the time (t = T + 2Δt),
Thereafter, similarly, every time the time Δt elapses, the SI value is calculated using the time-series data in the range of the time T starting from that time.

In the above-described real-time calculation of the present invention, as described above, the arithmetic processing device continues the same arithmetic processing from an appropriate time, such as the time when acceleration data is recorded, regardless of the occurrence or termination of an earthquake. Since it is not necessary to switch the operation mode, the operation is not complicated, and a stable operation can be obtained. Further, since the range of the time-series data used for calculating the SI value is the range of the second set time, it is possible to reduce the memory for storing the data at the time of the arithmetic processing and to reduce the calculation load.

Next, an example of a specific processing flow for each elapse of the second set time Δt in the above-described real-time calculation of the SI value will be described with reference to the flowchart of FIG. First, in step S1, parameters, that is, the first set time T and the second set time Δt are set. As will be described later, this setting can be appropriately performed in consideration of the SI value calculation error and the resource amount of the arithmetic processing unit. Next, in step S2, the original acceleration time is initialized, that is, the time R
Initialize to (t = 0) and start processing. Next, in step S3, the acceleration at the time when the time t has elapsed from the time R is input to a predetermined memory. Next, step S4
Then, the acceleration α _t input in step S3 is subjected to an operation that satisfies the equation of motion of a one-degree-of-freedom vibration system having a natural period ω, and a time response at time t and a natural period ω is calculated Sv _t ω. Next, in step S5, the velocity response spectrum is calculated. In step S6, if the current response is larger than the velocity response calculated in the processing loop up to that and stored as the maximum value, , Is stored as the maximum value in step S6. That is, the maximum value is updated, and if the previous value is larger, the process proceeds to the next step S7 without updating the maximum value. In step S7, the time is advanced by a predetermined time interval Δt ′, and the process proceeds to step S8 as time t = t + Δt ′. Note that Δt ′ is different from Δt of the second set time and corresponds to a sampling period of time-series data of acceleration. In step S8, it is determined whether or not the above process is completed in one cycle, that is, whether the process for the first set time T is completed. If it is determined that the process is not completed, the process returns to step S3, and The processing of steps S3 to S7 is repeatedly performed on the acceleration data at time t (= t + Δt), and the maximum value of the speed response spectrum is stored. If it is determined in step S8 that the processing for the first set time T has been completed, the process proceeds to the next step S9, where the SI value is calculated. After performing the calculation, after the second set time Δt has elapsed, the process proceeds to step S2, and the processes from steps S2 to S9 are repeatedly performed.

As described above, the first set time T and the second set time Δt are appropriately set in consideration of the SI value calculation error and the resource amount of the arithmetic processing unit. When the set time T of 1, ie, the calculation time is lengthened, the required memory and the amount of calculation increase, but the accuracy of the SI value improves. Conversely, when the length is shortened, the accuracy of the SI value decreases. , The required memory and the amount of calculation can be reduced. This is shown in FIG. 4 showing an example of a 95% confidence interval for the SI value obtained as defined when the first set time T is changed.

When the second set time Δt, ie, the calculation interval, is shortened, the amount of calculation increases but the accuracy of the SI value improves. Conversely, when the calculation interval is increased, the accuracy of the SI value decreases. However, the amount of calculation can be reduced. This is shown in FIG. 5 which shows an example of a 95% confidence interval for the SI value obtained as defined when the second set time Δt is changed.

If the above-described operation of calculating the SI value is performed on acceleration signals of seismic motion components in a plurality of directions, the maximum SI value can be reliably obtained by comparing these SI values. Can easily and reliably obtain the maximum value of the directional SI value, and can prevent underestimation of the damage caused by the earthquake depending on the installation direction of the seismometer.

In this case, the acceleration signals of the seismic motion components in a plurality of directions can be obtained from the seismometers installed corresponding to the respective directions. Two horizontal components detected by the meter,
The acceleration signal of at least two of the vertical components can also be obtained by vector synthesis, and the latter has an advantage that the required number of installed seismometers can be minimized as compared with the former.

FIG. 6 shows, as an example of the latter, a configuration in which acceleration signals in respective directions of seismometers arranged so as to detect two orthogonal horizontal components are vector-combined to calculate acceleration signals of eight horizontal components. This is a conceptual illustration of an example. Of course, the number of directions of the components to be calculated and the number of directions of the acceleration detected by the seismometer are also appropriate. In FIG. 6, reference numeral 13 denotes arithmetic processing means. The arithmetic processing means 13 synthesizes the acceleration signals of the north-south and east-west vibrations output from the detection units 12a and 12b into a vector as described later, and This is a configuration for calculating an acceleration component.
Then, the acceleration component in the desired direction obtained by the vector synthesis by the arithmetic processing means 13 is stored in the storage means 14 and used for subsequent arithmetic processing and the like. As described above, in the illustrated example, the direction in which the acceleration component is calculated by vector synthesis is a direction obtained by dividing all directions into eight, that is, θ = 0 °, 22.5 °, 45 °, 67. 5 ゜, 90
{11, 112.5, 135, 157.5}, and reference numerals 15a to 15h indicate respective storage units. Note that the directions of θ = 0 ° and 90 ° are detected by the detection units 12a and 12a, respectively.
Since the detection direction is based on 12b, vector synthesis is unnecessary.

FIG. 7 illustrates the principle of vector synthesis according to the present invention in the directions of θ (= 22.5 °) and θ ′ (= 135 °). The x-axis is east-west, and the y-axis is north-south. It corresponds to the direction. In the figure, X and Y indicate the accelerations detected by the detectors 12b and 12a at a certain point in time, respectively, and these acceleration vectors are projected and added in the θ direction to calculate the acceleration of the component in the θ direction. be able to. That is, assuming that the acceleration of the component in the θ direction is αθ, this αθ is calculated by an arithmetic expression of αθ = Xcosθ + Ysinθ. Similarly, the acceleration αθ of the component in the θ ′ direction is αα
θ ′ = Xcos θ ′ + Ysin θ ′. Thus, at a certain point in time, the detection units 12b and 12
By performing the above calculation for each of the directions set in advance with respect to the acceleration detected in a, the acceleration of the component in each direction can be calculated, and by continuously performing this at appropriate time intervals, And acceleration waveforms in desired directions, in this example, eight horizontal directions (including two directions requiring no calculation) can be continuously measured.

As described above, the acceleration components in the eight directions continuously measured as described above are processed through the respective storage units 15a to 15h of the storage means 14 for the subsequent processing for calculating the SI value. As described above, instead of calculating the SI value after calculating the acceleration components in all the desired directions, every time the acceleration component in each direction is calculated,
It is also possible to configure so that the SI value is calculated by the arithmetic processing described above.

As described above, the direction of the seismic motion component which is calculated and continuously measured by the vector synthesis is not limited to the above-described eight horizontal directions, and the number can be appropriately increased or decreased. Although resources and time required for processing are large, in this case, the maximum value of the calculated SI value has an advantage that an error from the SI value obtained as defined decreases, and conversely, the maximum value of the calculated SI value decreases. Then, there is an advantage that the resource and time required for calculating the SI value can be reduced while allowing an error of the SI value to some extent. still,
FIG. 4 shows a 95% confidence interval for the SI value obtained as defined when the number of directions to be measured is changed.

The above-described arithmetic processing can be performed by a single arithmetic processing means or by performing a plurality of arithmetic processing means in parallel.

[0027]

As described above, the present invention has the following effects. a. When an earthquake occurs, unlike the conventional method of calculating the SI value by returning to the time when the trigger is exceeded, the same calculation is always repeated to calculate the SI value without distinguishing between the time of the earthquake and the normal time. Can be simplified, and extremely stable operation can be guaranteed. b. Since the amount of data stored in each operation process is small, the calculation load can be reduced and the required memory amount can be reduced. c. By setting a plurality of directions for obtaining the SI value by the above operation, the maximum value of the SI value having direction dependency can be reliably obtained, and the evaluation accuracy of the influence of the building due to the earthquake can be improved. d. Item c. As a method of calculating acceleration components in a plurality of directions for obtaining SI values in a plurality of directions, a method of vector synthesis of acceleration signals of at least two components of a horizontal component and a vertical component is necessary. With a minimum seismometer, item c. The effect of can be achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram conceptually showing a real-time calculation method according to the present invention.

FIG. 2 is a system diagram conceptually showing an example of a configuration of a control seismometer to which the method of the present invention is applied.

FIG. 3 is a flowchart showing an example of a specific processing flow relating to the present invention.

FIG. 4 is an explanatory diagram showing an example of a 95% confidence interval with respect to an SI value obtained as defined when a first set time T is changed.

FIG. 5 is an explanatory diagram showing an example of a 95% confidence interval for an SI value obtained as defined when the second set time Δt is changed.

FIG. 6 is a system diagram illustrating an example of a method for measuring a seismic motion by vector synthesis.

FIG. 7 shows the principle of vector composition as θ (= 22.5 °).
FIG. 9 is a vector diagram illustrating directions of θ and θ ′ (= 135 °).

FIG. 8 is an explanatory diagram showing a 95% confidence interval for the SI value obtained as defined when the number of directions of acceleration of the seismic motion for calculating the SI value is changed.

FIG. 9 is an explanatory diagram of a conventional real-time calculation method for obtaining an SI value.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seismometer 2a, 2b Acceleration detection part 3 Arithmetic processing unit 4 Control part 11 Seismometer 12a, 12b Acceleration detection part 13 Arithmetic processing means 14 Storage means 15a-15h Storage part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Yanada 2-12-19 Shibuya, Shibuya-ku, Tokyo Yamatake Ha Newel Co., Ltd. (72) Inventor Hiroyuki Furukawa 2-12-19 Shibuya, Shibuya-ku, Tokyo Yamatake Honeywell Co., Ltd.

Claims (4)

[Claims] 1. An apparatus for sequentially recording acceleration data continuously output from a seismometer and calculating an SI value from time-series data in a first set time range in the recorded data. 2. A method for measuring an intensity of seismic motion, wherein an SI value calculation operation is repeatedly performed by shifting a range of time-series data by a second set time every time the set time elapses. 2. The method according to claim 1, wherein the calculation of the SI value is performed on acceleration signals of the seismic motion components in a plurality of directions. 3. An acceleration signal of a seismic motion component in a plurality of directions,
3. The method of measuring seismic intensity according to claim 2, wherein the method is obtained from seismometers installed corresponding to the respective directions. 4. An acceleration signal of a seismic motion component in a plurality of directions,
3. The method according to claim 2, wherein the acceleration signal of at least two of the two horizontal components and the vertical component detected by the seismograph is obtained by vector synthesis.