JP2015230206A - State monitoring system, information processing unit, state monitoring method, program, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a state monitoring system and the like capable of highly accurately performing a temporal soundness evaluation of a bridge pier.SOLUTION: A state monitoring system 1 for monitoring a state of a bridge pier 3 of a river bridge includes an acceleration sensor 11, a timer 13, and an information processing unit 15. The acceleration sensor 11 measures an acceleration of microtremor of the bridge pier 3. The information processing unit 15 calculates a power spectrum of the microtremor from the measurement result, where the information processing unit calculates, as an index value of the soundness, a ratio of a power spectrum area within a range from a vibration frequency fto a vibration frequency fto a power spectrum area within a range from a vibration frequency fto a vibration frequency fthat is larger than the vibration frequency fas a spectrum score.

Description

  The present invention relates to a pier state monitoring system, an information processing apparatus, a state monitoring method, a program, and a recording medium.

  There are many piers in the existing railway civil structures. Many of these have deteriorated due to aging, and high accuracy of maintenance and improvement of efficiency are required.

  As a conventional maintenance management technique, an impact vibration test is often employed in which vibration is applied to a structure and soundness is judged from the obtained data. For example, the surface of the structure is hit with a weight, vibration generated by the hit is detected by a sensor or the like, and the soundness of the structure is evaluated by a change in the natural frequency of the vibration (Patent Document 1). As a result, it is possible to discover deterioration due to defects that are difficult to detect visually.

JP 2007-51873 A

  In recent years, a technique based on state monitoring has been attracting attention in order to improve the accuracy and efficiency of maintenance management. This will monitor the measurement items that affect the soundness of civil engineering structures over the long term, detect abnormalities before the structure reaches the limit state, and take appropriate measures to extend the life of the structure. Is.

  As an example, in river bridges, the stability of piers is reduced by the action of scouring in addition to the action during an earthquake. In many cases, the scouring range gradually expands due to long-term external force, and a state monitoring method capable of accurately evaluating the soundness over time is desired.

  In this regard, the conventional evaluation method based on the impact vibration test requires time for measurement and requires a large apparatus, and thus is not suitable for state monitoring in which measurement is repeated over a long period of time and soundness is evaluated over time.

  An object of the present invention is to provide a state monitoring system and the like that can accurately evaluate the soundness of a pier over time.

  1st invention for solving the subject mentioned above is a state monitoring system of a pier, has a sensor and an information processor, the sensor measures vibration information of the pier, and the information processor From the waveform indicating the magnitude of vibration for each frequency obtained from the vibration information, as an index value of the soundness of the pier, the area of the waveform in the range of the frequency up to the first frequency The condition monitoring system is characterized in that a spectrum score that is a ratio of the area of the waveform in a frequency range up to a second frequency greater than the first frequency is calculated.

  According to the present invention, it is possible to calculate a spectrum score from vibration information obtained by measuring the microtremors of the pier due to wind or the like with a sensor, and to monitor the state of the pier using this as an index value of soundness. This spectrum score can be easily measured, and does not vary due to the difference in input to the pier, and is suitable for accurately evaluating the soundness over time.

The waveform is preferably a power spectrum waveform.
The magnitude of energy for each frequency can be expressed by the power spectrum, and the magnitude of the value for each frequency appears clearly. Therefore, by calculating the spectrum score based on the area of the power spectrum, it is possible to accurately evaluate the soundness.

The spectrum score is obtained by dividing the area of the waveform in the range from the third frequency to the second frequency by the area of the waveform in the range from the third frequency to the first frequency. It is desirable to calculate by
The spectrum score has a good proportional relationship with the natural frequency obtained by the conventional shock vibration test, and the soundness can be accurately evaluated.

The sensor preferably measures vibration information of the bridge pier in a direction orthogonal to the bridge axis.
The stability of the bridge pier in the direction perpendicular to the bridge axis affects the running safety in the bridge axis direction. Also, in river bridges, the sides of the piers in the direction perpendicular to the bridge axis are scoured, and the stability in that direction tends to decrease. Therefore, it is important to monitor the state of the pier, paying attention to the direction perpendicular to the bridge axis.

It is desirable that the first state monitoring system has a timer that defines a measurement time of the vibration information.
In the present invention, the measurement time is determined by a timer so that vibration information is measured when the train is not operating, for example, and the spectrum score can be calculated from the fine movement of the pier caused by wind or the like.

The pier is preferably a pier provided in a river.
In river bridges, the scouring range of the ground near the pier gradually widens, and the stability of the pier is often lowered in the long term, and is particularly suitable for long-term condition monitoring by applying the present invention.

2nd invention makes 1st frequency into an upper limit from the waveform which shows the magnitude | size of the vibration for every frequency obtained from the vibration information of the pier measured by the sensor as an index value of the soundness of the said pier A spectrum score, which is a ratio of the area of the waveform in the frequency range and the area of the waveform in the frequency range up to a second frequency greater than the first frequency, is calculated. Information processing apparatus.
The waveform is preferably a power spectrum waveform.
The spectrum score is obtained by dividing the area of the waveform in the range from the third frequency to the second frequency by the area of the waveform in the range from the third frequency to the first frequency. It is desirable to calculate by

  3rd invention is a state monitoring method of a bridge pier, Comprising: Information processing apparatus is the soundness of the said pier from the waveform which shows the magnitude | size of the vibration for every frequency obtained from the vibration information of the said pier measured by the sensor. As an index value of the sex, the area of the waveform in the range of the frequency up to the first frequency and the waveform in the range of the frequency up to the second frequency greater than the first frequency It is a state monitoring method characterized by calculating a spectrum score which is a ratio according to the area of.

  According to a fourth aspect of the present invention, the first frequency is used as an index value for the soundness of the pier from a waveform indicating the magnitude of vibration for each frequency obtained from the vibration information of the pier measured by a sensor. Information for calculating a spectrum score which is a ratio of the area of the waveform in the range of the frequency set as the upper limit and the area of the waveform in the range of the frequency set as the upper limit of the second frequency greater than the first frequency. It is a program for making it function as a processing device.

  According to a fifth aspect of the present invention, the first frequency is used as an index value of the soundness of the pier from a waveform indicating the magnitude of vibration for each frequency obtained from the vibration information of the pier measured by a sensor. Information for calculating a spectrum score which is a ratio of the area of the waveform in the range of the frequency set as the upper limit and the area of the waveform in the range of the frequency set as the upper limit of the second frequency greater than the first frequency. It is a recording medium recording a program for causing it to function as a processing device.

  According to the present invention, it is possible to provide a state monitoring system and the like that can accurately evaluate the soundness of a pier over time.

The figure which shows the pier 3 which provided the state monitoring system 1 The figure which shows the structure of the state monitoring system 1 The figure which shows the hardware constitutions of the information processing apparatus 15 The flowchart which shows the flow of the state monitoring method of the pier 3 Diagram showing an example of a Fourier amplitude spectrum Figure showing an example of power spectrum Diagram showing changes in spectrum score and dominant frequency over time Diagram showing changes in spectrum score and dominant frequency over time Diagram showing the relationship between spectrum score and natural frequency

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

(1. Condition monitoring system 1)
FIG. 1 is a view showing a pier 3 provided with a state monitoring system 1. FIG. 1 (a) is a view of the pier 3 viewed from the side, and FIG. 1 (b) is a view of the pier 3 viewed from above. . The state monitoring system 1 according to the present embodiment monitors the state of the pier 3. The figure shows an example of a river bridge. The pier 3 is provided in the river 20 and supported by a ground 30 at the bottom of the water.

  The state monitoring system 1 is provided on the pier 3. The bridge pier 3 supports a bridge girder 5, and a train track is provided on the bridge girder 5.

  In the state monitoring system 1, the state of the pier 3 is monitored by measuring the fine movement in the direction orthogonal to the axial direction of the bridge girder 5. The microtremor is a micro vibration that always occurs in the pier 3 due to, for example, the influence of wind or water flow. In the following, the axial direction of the bridge girder 5 is referred to as the bridge axis direction, and the direction orthogonal to the bridge axis direction is referred to as the bridge axis orthogonal direction. The bridge axis direction corresponds to the horizontal direction in FIG. 1B, and the bridge axis orthogonal direction corresponds to the vertical direction in FIG.

  The reason for measuring microtremors in the direction orthogonal to the bridge axis is that the stability in that direction particularly affects the running safety of the train. Moreover, in the river bridge, the ground 30 on the side of the pier base in the direction perpendicular to the bridge axis is scoured by the water flow 21 shown by the arrow in FIG. 1B, and the stability in the direction perpendicular to the bridge axis tends to be impaired. Therefore, it is important to monitor the state of the pier 3 by paying attention to the direction orthogonal to the bridge axis.

  FIG. 2 is a diagram showing a configuration of the state monitoring system 1. The state monitoring system 1 includes an acceleration sensor 11, a timer 13, an information processing device 15, and the like, and is driven by a battery (not shown).

  The acceleration sensor 11 is a sensor that measures the acceleration (vibration information) of the pier 3 at all times and uses a highly accurate uniaxial accelerometer capable of detecting minute vibrations. As the acceleration sensor 11, for example, a MEMS accelerometer can be used. By using the MEMS accelerometer, it can be driven at low cost and with low power consumption.

  The timer 13 is set with information on measurement time for measuring acceleration by the acceleration sensor 11. In this embodiment, the measurement time is set when the train is not operating.

  The information processing device 15 controls the acceleration sensor 11 to measure acceleration during the above measurement time, and calculates a spectrum score to be described later based on the measurement result. Information necessary for maintenance of the pier 3 such as the calculated spectrum score is recorded on a recording medium such as an SD card.

  FIG. 3 shows a hardware configuration of the information processing apparatus 15. The information processing apparatus 15 can be realized by a computer in which a control unit 151, a storage unit 152, an input unit 153, a media input / output unit 154, a display unit 155, a communication unit 156, and the like are connected via a bus 157. However, the configuration of the information processing apparatus 15 is not limited to this.

  The control unit 151 includes a CPU, a ROM, a RAM, and the like. The CPU calls a program or the like related to processing described later of the information processing apparatus 15 stored in the storage unit 152, ROM, recording medium, or the like to the work memory area on the RAM and executes it, thereby realizing the processing. The ROM is a non-volatile memory and permanently holds programs, data, and the like. The RAM is a volatile memory, and temporarily stores programs, data, and the like loaded from the storage unit 152, ROM, recording medium, and the like, and includes a work area used by the control unit 151 to perform various processes.

The storage unit 152 is a hard disk drive, a solid state drive, or the like, and stores a program executed by the control unit 151, data necessary for program execution, and the like.
The input unit 153 is for performing operation instructions, operation instructions, data input, and the like.
The media input / output unit 154 inputs / outputs data to / from the media. As the medium, for example, a recording medium such as an SD card is used.

The display unit 155 includes a display device such as a liquid crystal panel and a logic circuit for realizing a display function in cooperation with the display device.
The communication unit 156 is a communication interface that mediates communication via a network or the like.
The bus 157 is a path that mediates transmission / reception of control signals and data signals between the respective units.

  The configuration of the state monitoring system 1 is not limited to the above. For example, in addition to the acceleration sensor 11 described above, an acceleration sensor that detects a relatively large vibration when passing through the train can be added to use for maintenance management of the pier 3. As this sensor, for example, a MEMS accelerometer capable of measuring acceleration in two or three axes can be used, although the measurement accuracy of minute vibrations is somewhat lowered.

(2. State monitoring method of pier 3)
Next, a state monitoring method for the pier 3 by the state monitoring system 1 will be described. FIG. 4 is a flowchart showing a flow of the state monitoring method of the pier 3, and each step is a process executed by the control unit 151 of the information processing device 15.

  In the present embodiment, the information processing device 15 controls the acceleration sensor 11 during the measurement time set by the timer 13 and measures the acceleration of fine movement caused by wind or the like as vibration information of the pier 3. The information processing device 15 acquires the acceleration of fine movement from the acceleration sensor 11 (S1). As described above, the measurement time is when the train is not in operation, for example, 5 times every 30 minutes between 2 am and 4 am in the midnight when the train does not operate (one measurement is, for example, 16 seconds). Set the measurement time.

  The information processing device 15 analyzes the waveform of the change in acceleration over the measurement time by a known method, and calculates a Fourier amplitude spectrum (S2).

  The Fourier amplitude spectrum indicates the magnitude of vibration for each frequency in terms of amplitude. An example of the Fourier amplitude spectrum is shown in FIG. 5A and 5B are graphs showing Fourier amplitude spectra of two piers 3 in the river 20 with the horizontal axis representing the frequency and the vertical axis representing the amplitude.

  The information processing device 15 calculates a power spectrum from the Fourier amplitude spectrum (S3).

  In brief, the power spectrum indicates the magnitude of vibration for each frequency in terms of the square of the amplitude, and can express wave energy in frequency units. An example of the power spectrum is shown in FIG. FIGS. 6A and 6B are graphs showing the power spectrum for the Fourier amplitude spectrum of FIGS. 5A and 5B, with the horizontal axis representing the frequency and the vertical axis representing the square value of the amplitude. . As shown in the figure, in the power spectrum, the level of the value clearly appears compared to the Fourier amplitude spectrum.

  The information processing device 15 calculates a spectrum score from the power spectrum as an index value indicating the soundness of the pier 3 (S4).

As shown in FIG. 6, the spectrum score has an area of a power spectrum waveform in a range A with the frequency f ₀ (third frequency) as the lower limit and the frequency f ₁ (first frequency) as the upper limit. And the ratio by the area of the waveform of the power spectrum in the range B with the frequency f ₀ as the lower limit and the frequency f ₂ (second frequency) greater than the frequency f ₁ as the upper limit. Each frequency can be arbitrarily determined on condition that f ₀ <f ₁ <f ₂ .

In this embodiment, the area of the power spectrum waveform in the range B is divided by the area of the power spectrum waveform in the range A to obtain the ratio value. That is, the calculation formula of the spectrum score is expressed as the following formula (1). In addition, the power spectrum area of the following formula (1) indicates the area of the waveform of the power spectrum described above (the integrated value of the waveform).
[Spectrum Score _{= (the} power spectrum area to f 0 ~f _{2) / (power} spectrum area to _{f 0 ~f 1) ... (1} )

  For example, the information processing device 15 calculates a spectrum score from each microtremor obtained by measurement five times a day as described above, and records the average value as a spectrum score on the measurement date, such as an SD card. Store in a medium or the like.

  In the present embodiment, the above procedure is repeated, and the spectrum score is calculated over time, so that long-term monitoring of the pier 3 can be simplified. Furthermore, it is also possible to determine the soundness of the pier 3 using this spectrum score. A specific example will be described later.

  In the present embodiment, the spectrum score is calculated by the information processing device 15. However, for example, the above-described Fourier amplitude spectrum or power spectrum data is input to a remote information processing device, and the spectrum score is calculated by the information processing device. It is also possible to perform. In that case, the information processing apparatus is also included in the state monitoring system 1.

(3. Effectiveness of spectrum score)
In the present embodiment, the reason why the spectrum score is calculated as the index value of the soundness of the pier 3 is that it is suitable for monitoring the state of the pier 3 and is effective as the index value of the soundness.

  That is, as can be seen from FIG. 5, unlike the shock vibration test, since the extreme amplitude does not appear in the Fourier amplitude spectrum due to disturbance or the like in the constant tremor measurement, it is difficult to specify the natural frequency. In the measurement of microtremors, the input is not constant as in the case of the impact vibration test, and the measurement result is easily affected by fluctuations in the input. For example, if the input is large, the amplitude of the Fourier amplitude spectrum may increase overall.

  Therefore, in the present embodiment, the above-described spectrum score is used as an index value that is suitable for monitoring the state of the pier 3 and that is not affected by input fluctuations and is effective for evaluating the soundness. The spectrum score normalizes the power spectrum area and expresses how excellent the low frequency region is in the waveform of the power spectrum, and can exclude the influence of the magnitude of the amplitude due to the fluctuation of the input.

  7 (a) and 7 (b) show the time course of the spectrum score and dominant frequency of the pier 3 in the river 20 during the state monitoring period (about 3 months), the horizontal axis is the measurement date, and the vertical axis is the spectrum. It is a figure shown as a score or a dominant frequency. The dominant frequency is a value obtained for comparison with the spectrum score, and is the frequency at which the amplitude is maximum in the Fourier amplitude spectrum.

  7 (a) and 7 (b), even if the same pier 3 is used, the fluctuation at each measurement day is not large and stable at the dominant frequency, whereas the fluctuation is relatively small at the spectrum score and tends to become a stable value. I can confirm.

  FIGS. 8A and 8B are graphs showing the time-dependent changes in the spectrum score and the dominant frequency for the other two piers 3 in the river 20 as in FIG. The two bridge piers 3 have different natural frequencies according to the impact vibration test, and are 7.9 Hz (pier pier a) and 4.4 Hz (pier pier b), respectively.

  8 (a) and 8 (b), when the piers 3 having different natural frequencies are compared, the spectrum score is different from the natural frequency, whereas the dominant frequency is close and the spectrum score is more specific. It can be seen that the magnitude of the frequency can be expressed well.

FIG. 9 is a diagram showing the relationship between the spectrum score and the natural frequency obtained by the impact vibration test. The horizontal axis represents the natural frequency and the vertical axis represents the spectrum score and the natural frequency of each of the plurality of piers 3 in the river 20. Is plotted as a spectrum score. When calculating the spectrum score, the values of f ₀ , f ₁ , and f ₂ were set to 1 Hz, 4 Hz, and 20 Hz, respectively.

  FIG. 9 shows that there is a good proportional relationship between the spectrum score and the natural frequency.

  As described above, the spectrum score has a good proportional relationship with the natural frequency obtained by the conventional shock vibration test, the magnitude relationship can be appropriately expressed, and the fluctuation of the value is small. Therefore, it can be said that the soundness of the pier can be accurately and quantitatively evaluated by state monitoring using the spectrum score as an index value in the same manner as the natural frequency.

(4. Judgment of soundness of pier 3)
At the time of state monitoring, the soundness determination using the spectrum score can be performed by the information processing device 15 or the remote information processing device described above.

  For example, by determining the reference value of the spectrum score in advance, the soundness can be determined by comparison with the reference value. When the spectrum score falls below the reference value, an abnormality is detected, and an alarm such as an alarm sound or warning display is issued by a predetermined alarm device (not shown), for example. In response to this, detailed inspections and repairs can be performed by an impact vibration test or the like.

  The reference value can be determined from the relationship with the natural frequency during the impact vibration test. For example, when the standard value of the natural frequency related to the stability of the pier 3 is 4.0 Hz, it can be seen from the proportional relationship of FIG. 9 that the corresponding spectrum score is about 1.0. It can be used as a value.

  In addition, when the degree of reduction of the spectrum score is large, it can be determined that there is a possibility of abnormality. For example, as shown in C of FIG. 7A, an approximate line that approximates the temporal change of the spectrum score for a certain period is calculated, and the soundness is reduced when the slope of the approximate line C falls below a predetermined negative value. The degree is large and it can be determined that there is a possibility of abnormality.

  Alternatively, a representative value such as an average value of spectrum scores is obtained for each of the most recent fixed period and the past fixed period, and the representative value of the most recent fixed period is lower than the representative value of the past fixed period by a predetermined value or more. If there is a problem, it can also be determined that there is a risk of abnormality.

  As described above, according to the state monitoring system 1 of the present embodiment, the spectrum score can be calculated from the constant fine movement of the pier 3 due to wind or the like, and the state of the pier 3 can be monitored using this as a soundness index value. This spectrum score can be easily measured, and does not vary due to a difference in input to the pier 3, and is suitable for accurately evaluating the soundness over time.

  In the present embodiment, the magnitude of energy for each frequency can be expressed by the power spectrum, and the magnitude of the value for each frequency appears clearly. Therefore, by calculating the spectrum score based on the power spectrum area, it is possible to accurately evaluate the soundness. However, a value similar to the spectrum score can be calculated as an index value from the Fourier amplitude spectrum as shown in FIG.

Moreover, in this embodiment, the spectrum score which has a favorable proportional relationship with the natural frequency by the conventional impact vibration test can be calculated by the above formula (1), and the soundness of the pier 3 can be accurately evaluated. However, the spectrum score only needs to be able to express the degree of excellence in the low frequency region. If necessary, the inverse of the right side of equation (1) is used, or the power spectrum area and vibration in an arbitrary range up to the frequency f ₁ are used. Changes such as a ratio according to the power spectrum area in an arbitrary range up to a number f ₂ (> f ₁ ) are possible.

  Since the acceleration sensor 11 measures the acceleration in the direction perpendicular to the bridge axis, it is possible to suitably monitor the state of stability in the direction perpendicular to the bridge axis that particularly affects the traveling safety in the bridge axis direction. Moreover, in the river bridge, the side of the bridge pier 3 in the direction perpendicular to the bridge axis is scoured, and the stability in the direction tends to be lowered. In this respect, it is important to monitor the state in the direction perpendicular to the bridge axis. However, it is also possible to measure microtremors in the direction of the bridge axis as necessary.

  Moreover, in the state monitoring system 1, since the measurement time is determined by the timer 13, the measurement time is set to a time when the train or the like is not in operation, and the spectrum score can be calculated from the fine movement of the pier 3 caused by wind or the like. For example, when measuring vibrations when running trains, etc., the results may vary greatly due to differences in trains, etc., and if the train operation becomes impossible due to abnormalities, etc., measurement will not be possible. There is no such fear in form.

  In the present embodiment, the example of the bridge pier 3 of the river bridge is described as the state monitoring target pier. However, the present invention is not limited thereto, and a viaduct pier may be used. However, in river bridges, the scouring area of the ground near the pier gradually widens and the stability is often lowered in the long term, and is particularly suitable for long-term condition monitoring by applying the present invention.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these are naturally within the technical scope of the present invention. Understood.

1; condition monitoring system 3; pier 5; bridge girder 11; acceleration sensor 13; timer 15; information processing device 20; river 21; water flow 30;

Claims (12)

A pier condition monitoring system,
Having a sensor and an information processing device,
The sensor measures vibration information of the pier,
The information processing apparatus includes:
From the waveform indicating the magnitude of vibration for each frequency obtained from the vibration information, as an index value of the soundness of the pier, the area of the waveform in the frequency range with the first frequency as the upper limit, 2. A state monitoring system, comprising: calculating a spectrum score that is a ratio of a frequency range up to a second frequency larger than the first frequency, depending on an area of the waveform.   The state monitoring system according to claim 1, wherein the waveform is a waveform of a power spectrum.   The spectrum score is obtained by dividing the area of the waveform in the range from the third frequency to the second frequency by the area of the waveform in the range from the third frequency to the first frequency. The state monitoring system according to claim 1, wherein the state monitoring system calculates the state.   The state monitoring system according to any one of claims 1 to 3, wherein the sensor measures vibration information of the bridge pier in a direction perpendicular to the bridge axis.   The state monitoring system according to any one of claims 1 to 4, further comprising a timer that determines a measurement time of the vibration information.   The state monitoring system according to any one of claims 1 to 5, wherein the pier is a pier provided in a river.   From the waveform indicating the magnitude of the vibration for each frequency obtained from the vibration information of the pier measured by the sensor, as an index value of the soundness of the pier, the frequency in the range of the frequency up to the first frequency An information processing apparatus that calculates a spectrum score that is a ratio of an area of a waveform and a frequency range in which the second frequency greater than the first frequency is an upper limit, by the area of the waveform.   The information processing apparatus according to claim 7, wherein the waveform is a waveform of a power spectrum.   The spectrum score is obtained by dividing the area of the waveform in the range from the third frequency to the second frequency by the area of the waveform in the range from the third frequency to the first frequency. The information processing apparatus according to claim 7, wherein the information processing apparatus calculates the information. A method for monitoring the state of a pier,
Information processing device
From the waveform indicating the magnitude of vibration for each frequency obtained from the vibration information of the bridge pier measured by the sensor, as an index value of the soundness of the bridge pier, the frequency range with the first frequency as the upper limit A state monitoring method, comprising: calculating a spectrum score that is a ratio of an area of the waveform and an area of the frequency up to a second frequency larger than the first frequency, by the area of the waveform. Computer
From the waveform indicating the magnitude of the vibration for each frequency obtained from the vibration information of the pier measured by the sensor, as an index value of the soundness of the pier, the frequency in the range of the frequency up to the first frequency A program for functioning as an information processing device that calculates a spectrum score that is a ratio of an area of a waveform and a frequency range within a range of frequencies up to a second frequency greater than the first frequency. Computer
From the waveform indicating the magnitude of the vibration for each frequency obtained from the vibration information of the pier measured by the sensor, as an index value of the soundness of the pier, the frequency in the range of the frequency up to the first frequency A program for functioning as an information processing device that calculates a spectrum score that is a ratio of a waveform area to a frequency range within a range of frequencies up to a second frequency greater than the first frequency. Recorded recording medium.

Images