JP2007270552A - Signal processing method, signal processing program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signal processing method, etc. applicable to the maintenance and management of large-sized structures for their diagnosis using ordinary structural vibrations; this method being objective and quantitative, and capable of everyday real-time monitoring of the structures. <P>SOLUTION: Signals arising out of vibrations of bridge piers 12 are received with acceleration sensors and/or velocity sensors 14a or the like installed on a plurality of designated positions on the piers 12 and connected with a signal processing unit 20 following a designated formula. These vibrations are due to one or more causes among weight shocks, wind forces and motorcars. As the designated positions, two or more points located between the top and bottom of each pier 12 are suitable. Next, a plurality of received signals is treated by an independent component analysis to extract one or more independent components. The extracted one or more independent components are put to a spectrum analysis to obtain the characteristic vibration frequency of the pier 12. A diagnosis is made on any strength deterioration of the pier 12 by comparing the obtained characteristic vibration frequency thereof with the designated reference value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a signal processing method for processing a signal generated by vibration of an object by a signal processing device.

  Social capital, especially large buildings such as bridges, roads, ports, and educational facilities, are inevitably subject to aging and becoming obsolete over the years since they were built and maintained. In the near future, it is said that the cost of maintenance and repairs for these large buildings will exceed half of the total investment in construction. For this reason, the above large-scale building is changed from a method of breaking and newly building to a method of proactively repairing an existing large-scale building and extending the useful life, that is, extending the life of the building. There is an increasing need to reduce the burden.

  Among social capital, bridges are not only large-scale buildings, but once a failure occurs in a bridge, the impact on the traffic network is interrupted, so it is very economical and social. Most of the bridges are made of reinforced concrete or steel frame and have a design life of 50 to 60 years. Around 2010, more than half of the bridges will be over 40 years old, and around 2020-2030, there will be a sudden increase in the number of bridges with a lifetime exceeding 50 years, so these bridges must be renewed. It is said. Originally, since concrete is a material with high durability, it is considered that the production of 1000-year concrete is not impossible if high-quality materials and advanced technology are applied. On the other hand, it is also true that there is a case where the deterioration of the bridge becomes apparent within 20 years after the construction of the bridge. The causes of these cases are considered to be deterioration phenomena that were not known at the time of construction, and that past design technology levels did not correspond to the current situation. As vehicles have become larger and traffic volume has increased, they have become overloaded with respect to the weight of bridges assumed at the time of past design, and the reinforced concrete structures used in most bridges are temporarily salinized. In consideration of the fact that gravel containing more than the specified value was used, and exposure to sea breezes when the bridge was installed near the coast, the useful life of the bridge could be shortened from the previous design value. There is. In the case of bridges over rivers, the overall strength is achieved by burying and fixing the foundations of the piers at the bottom of the river. However, as the water retention capacity of forests decreases due to the development of river basins, etc., the river velocities after rainfall increase in the river basins, so scouring of the pier foundations is easy to proceed. For this reason, there are cases where the strength deterioration of the bridge is accelerated. As is clear from the above, the number of bridges that require maintenance and repairs will increase rapidly in the future.

The maintenance and diagnosis methods for road structures such as bridges, tunnels, dams, retaining walls, river structures such as locks and pipes, harbor structures, water supply and sewerage facilities, etc. Although it differs depending on the manager, the following methods are generally adopted (see Non-Patent Documents 1 to 5).
1. Periodic inspection / inspection (primary inspection): Understanding the degree of deterioration, estimating the cause of deterioration Enumerating inspection / inspection methods, damage / deformation inspection, structure inspection / inspection, external deformation inspection, soundness inspection, visual visual inspection , Hammering inspection, infrared method, X-ray method, nondestructive inspection, corrosion investigation, load bearing investigation, crack investigation, core sampling, Schmitt hammer, etc.
2. Deterioration test / evaluation / prediction (secondary inspection): Prediction of deterioration over time, evaluation compared with required performance (1) List test / measurement methods, static loading test, durability test, stress frequency measurement, There are material tests, compressive strength tests, deterioration tests, nondestructive tests, displacement measurements, fatigue tests, and the like.
(2) Enumeration of evaluation / judgment methods includes soundness diagnosis (cracking cause investigation and investigation of countermeasures), durability evaluation (neutralization, salt damage, alkali aggregate reaction, rust / corrosion), load capacity evaluation ( (Live load, fatigue, temperature, earthquake), displacement / deformation studies (foundation settlement / tilt, creep, lateral flow, vibration), etc.
(3) Enumerating prediction methods includes deterioration prediction (possibility of falling concrete pieces), life cycle cost prediction, service life prediction, and the like.
3. Judgment and selection of countermeasures: Repair methods, reinforcement methods (1) List of repair methods include surface coating, crack injection / filling, cross-section repair, surface coating, and anti-corrosion.
(2) Reinforcement methods are listed, such as replacement, concrete winding, steel plate adhesion, and support point expansion.

  First, the primary inspection of periodic inspections / surveys is performed, and based on the results, it is determined whether or not a more detailed secondary inspection is to be performed. When conducting secondary inspections, destructive tests (including cross-section inspection by cutting out concrete cores) including deterioration tests, evaluations, and predictions, non-destructive tests (impact vibration used to estimate the progress of scouring of pier foundations) Law). As a result, a determination is made as to whether repair or reinforcement is better. If it is determined that repair / reinforcement will be performed, determine what repair method and reinforcement method should be selected.

Published by Tatsuo Tanikawa, “Non-destructive inspection and diagnosis method for concrete structures”, Cement Journal, September 17, 2004. Published by Kazusuke Kobayashi, “Diagnosis Method for Deterioration of Concrete Structures by Collecting Cores”, Morikita Publishing Co., Ltd., December 28, 2001. Written by Kazutaka Suzuki, Yoichi Nojiri, and Yasunori Matsuoka, “Diagnosis of Concrete Structure,” published by Morikita Publishing Co., Ltd., September 30, 1003. Published by Kiyoshi Katawaki, “Latest Concrete Corrosion Protection and Repair Technology”, Sankai-do Co., Ltd., September 16, 1999. Supervised by Kento Uomoto, “Inspection and Diagnosis of Concrete Structures-Nondestructive Inspection Guidebook”, Riko Bunko Co., Ltd., August 11, 2003.

  In the conventional maintenance management and diagnosis methods for reinforced concrete bridges, destructive inspections such as non-destructive inspection such as hammering inspection or visual inspection described above, and cross-sectional inspection by cutting out concrete cores, etc. are carried out about once every two years. It was. However, the hitting sound inspection or the visual appearance inspection has a problem that it is qualitative and low in accuracy because it is a sensory inspection. Since the inspection was conducted about once every five years, there was a problem that it could not cope with a real-time inspection considered necessary in an emergency such as a storm. Although the above-mentioned shock vibration method is used to estimate the scouring progress of the pier foundation, this method is a large-scale method, so it cannot be used to collect bridge health data on a daily basis. There has been a problem that it requires vibration other than vibration.

  Therefore, an object of the present invention is to solve the above-described problems, and to provide an objective and quantitative signal processing method that can be used for maintenance and diagnosis of large buildings and diagnostic methods. is there.

  The second object of the present invention is to provide a signal processing method and the like that can be used for maintenance and diagnosis of large buildings and that can be constantly monitored in real time.

  A third object of the present invention is to provide a signal processing method using normal vibrations that can be used for maintenance and diagnosis of large buildings and diagnostic methods.

  The signal processing method according to the present invention is a signal processing method in which a signal generated by vibration of an object is processed by a signal processing device, and the signal generated by vibration of the object is converted into a plurality of predetermined positions of the object. A receiving step that is received by a predetermined sensor group that is installed in a predetermined manner and connected to the signal processing device, and a plurality of signals received by the receiving step are processed by independent component analysis to obtain one or more independent components An extraction step for extracting, and a natural frequency acquisition step for acquiring a natural frequency of the object by performing spectral analysis on one or more independent components extracted by the extraction step.

  Here, in the signal processing method according to the present invention, a diagnostic step of diagnosing strength deterioration of the object based on a comparison between the natural frequency of the object acquired in the natural frequency acquisition step and a predetermined reference value. Furthermore, it can be provided.

  Here, in the signal processing method according to the present invention, the diagnosis step acquires the natural frequency of the object acquired in the natural frequency acquisition step over a plurality of times, and includes a plurality of natural frequencies. Based on a comparison between the maximum or minimum natural frequency and a predetermined reference value, the strength deterioration of the object can be diagnosed.

  Here, in the signal processing method of the present invention, the object may be a pier, and the plurality of predetermined positions may be two or more positions between an upper part and a lower part of the pier.

  Here, in the signal processing method of the present invention, the predetermined sensor group may be an acceleration sensor and / or a speed sensor.

  Here, in the signal processing method of the present invention, the vibration of the object may be caused by any one or more of weight impact, wind force, and vehicle.

  Here, in the signal processing method according to the present invention, when the vibration of the object includes a thing caused by a vehicle, the reception step is the predetermined position at one or more points around the object or the object, A signal generated by vibration of the object from a point when a value measured by a strain gauge installed at a position different from a plurality of predetermined positions and connected to the signal processing apparatus in a predetermined manner exceeds a predetermined value. It can be received by a predetermined sensor group installed at the plurality of predetermined positions of the object.

  Here, in the signal processing method of the present invention, the predetermined method may be wireless and / or wired.

  The signal processing program of the present invention is a signal processing program for processing a signal generated by vibration of an object by a signal processing device, and the signal generated by the vibration of the object is transmitted to a computer of the signal processing device. A reception step of receiving a predetermined sensor group installed at a plurality of first predetermined positions of the object and connected to the signal processing device in a predetermined manner; and a plurality of signals received by the reception step as independent components An extraction step for extracting one or more independent components by processing by analysis, and a natural frequency acquisition step for obtaining a natural frequency of the object by performing spectral analysis on the one or more independent components extracted by the extraction step. This is a signal processing program for execution.

  Here, in the signal processing program according to the present invention, a diagnostic step for diagnosing strength deterioration of the object based on a comparison between the natural frequency of the object acquired in the natural frequency acquisition step and a predetermined reference value. Furthermore, it can be provided.

  Here, in the signal processing program of the present invention, the diagnosis step acquires the natural frequency of the object acquired in the natural frequency acquisition step over a plurality of times, and includes the plurality of natural frequencies. Based on a comparison between the maximum or minimum natural frequency and a predetermined reference value, the strength deterioration of the object can be diagnosed.

  Here, in the signal processing program of the present invention, the object may be a pier, and the plurality of predetermined positions may be two or more positions between an upper part and a lower part of the pier.

  Here, in the signal processing program of the present invention, the predetermined sensor group may be an acceleration sensor and / or a speed sensor.

  Here, in the signal processing program of the present invention, the vibration of the object may be caused by any one or more of weight impact, wind force, and vehicle.

  Here, in the signal processing program of the present invention, when the vibration of the object includes a thing caused by a vehicle, the receiving step is the predetermined position at one or more points around the object or the object, A signal generated by vibration of the object from a point when a value measured by a strain gauge installed at a position different from a plurality of predetermined positions and connected to the signal processing apparatus in a predetermined manner exceeds a predetermined value. It can be received by a predetermined sensor group installed at the plurality of predetermined positions of the object.

  Here, in the signal processing program of the present invention, the predetermined method may be wireless and / or wired.

  The recording medium of the present invention is a computer-readable recording medium on which any one or two or more signal processing programs of the present invention are recorded.

  According to the signal processing method and the like of the present invention, the signal generated by the vibration of the pier is detected by an acceleration sensor and / or a speed sensor installed at a plurality of predetermined positions on the pier and connected to the signal processing device in a predetermined manner. Receive. The vibration is caused by one or more of weight impact, wind force, and vehicle. The predetermined position is preferably two or more positions between the upper part and the lower part of the pier. Next, the plurality of received signals are processed by independent component analysis to extract one or more independent components. One or more extracted independent components are spectrally analyzed to obtain the natural frequency of the pier. Based on the comparison between the acquired natural frequency of the pier and a predetermined reference value, the strength deterioration of the pier is diagnosed. As a result, it can be used for maintenance and diagnosis of large buildings or their components, and it can be monitored objectively and quantitatively, and can be monitored daily and in real time. There is an effect that it can be provided.

  Hereinafter, each embodiment will be described in detail with reference to the drawings.

  In the first embodiment, the signal processing method and the like of the present invention will be described first, then a simulation performed to confirm the validity of the signal processing method and the like will be described, and finally the validity of the signal processing method and the like will be described. The field experiment conducted to confirm the above will be described.

  FIG. 1 shows an environment in which a signal processing method according to Embodiment 1 of the present invention is used. In FIG. 1, reference numeral 10 is a bridge as an example of a large structure, 24 and 26 are vehicles that travel on the bridge 10, 12 is an example of a component of the bridge 10, and a pier (object) that supports the bridge 10, 16. Is a strain sensor attached to the lower part of the bridge 10, and 14a, 14b and 14c are sensor groups such as a speed sensor or an acceleration sensor attached to the pier 12 (predetermined sensor group; hereinafter referred to as "sensor 14a etc."). , 20 is a signal processing device, 18 is a cable for connecting the sensor 14a and the like to the signal processing device 20, and 22 is a weight used for hitting the pier 12 in the direction of arrow A in an impact vibration experiment. The signal processing device 20 can be realized by installing the signal processing program of the present invention in the personal computer PC. As shown in FIG. 1, the coordinate axis is the X axis in the horizontal direction (left direction is positive in FIG. 1), the Y axis is in the vertical direction (upward direction is positive in FIG. 1), and FIG. Thus, the direction perpendicular to the paper surface is the Z-axis (the depth direction in FIG. 1 is positive).

  FIG. 2 is a flowchart showing the processing flow of the signal processing method or signal processing program according to the first embodiment of the present invention. As shown in FIG. 2, first, signals generated by vibration of the pier 12 are installed at a plurality of predetermined positions on the pier 12 and are connected to the signal processing device 20 and the cable 18 (predetermined system) by a sensor 14a or the like. Is sent to the signal processing device 20 (reception step, step S10). As shown in FIG. 1, the cause of the vibration of the bridge pier 12 is due to the impact in the direction of arrow A by the weight 22, in the case of wind force in the X-axis or Z-axis direction, etc. Or the case of any one or more of these. The plurality of predetermined positions of the pier 12 may be two or more positions between the upper part and the lower part of the pier 12 like the positions where the sensors 14a, 14b and 14c shown in FIG. 1 are installed. Is preferred. Although three places are shown as a plurality of predetermined positions in FIG. 1, it is not limited to three places. The sensor 14a or the like is preferably an acceleration sensor or a speed sensor. Both sensors may be used in combination. As the acceleration sensor, for example, a piezoelectric accelerometer (manufactured by Lion Co., Ltd. (registered trademark), PV-85, PV-93, etc.), a servo accelerometer (manufactured by Tokyo Metropolitan Co., Ltd., VSE-15D) or the like is used. Can do. The speedometer may be a general one. Speedometers are more expensive than accelerometers, but they are more accurate. As the predetermined method, wired such as the cable 18 shown in FIG. 1 may be used, or wireless may be used. A combination of wired or wireless may be used. It is preferable to configure a wireless sensor network using radio.

  Next, the signal processing device 20 processes the plurality of signals received in the reception step (step S10) by independent component analysis to extract one or more independent components (extraction step; step S12). Independent component analysis (ICA) is a technique for finding hidden factors or components from multivariate (multidimensional) data. More specifically, independent component analysis is a technique for restoring original independent signals from observed signals when signals from two or more independent signal sources are linearly mixed and observed. . As a condition for the application, the signal of the signal source does not follow a normal distribution (non-Gaussian), and the signals of the signal source need to be statistically independent from each other. When restoring signals, the order and magnitude of the restored signals are not limited. As an application example, when a large number of people are talking at the same time, a voice of a specific person is extracted from them, and when many radio waves are distorted and mixed in a mobile phone etc., those radio waves are restored There are various application examples such as a method, a method of observing an electroencephalogram or a magnetoencephalogram outside the brain, and separating and capturing signals generated inside the brain.

  The purpose of independent component analysis is to represent multiple observed variables as a linear combination of statistically independent variables. Independent variables calculated from observed variables are independent components. Here, the basic concept of independent component analysis will be described. First, it is assumed that the original signal s (t) is given by a vector represented by Equation 1.

The average of each component s _i (t) (i = 1 to n) of the original signal s (t) is 0, and each component s _i (t) is independent of each other. A signal obtained by mixing these n original signals with a linear sum is taken as an observation signal x (t) expressed by Equation 2.

  Here, the relationship between the original signal s (t) and the observed signal x (t) can be expressed as in Expression 3 using the mixing matrix A.

  This mixing matrix A is a matrix of m × n (number of dimensions of observation signal × number of components of independent signal). In the independent component analysis, it is considered that the original signal s (t) can be obtained by linear conversion from the observed signal x (t). This restoration matrix is W, and the estimated original signal y (t) is

  Then, the relationship between the observed signal x (t) and the estimated original signal y (t) is expressed as Equation 5.

  From Equation 5, the estimated original signal y (t) can be obtained by finding the restoration matrix W. Accordingly, the independent component analysis is a method for estimating the original signal s (t) representing the independent component from the observed signal x (t) without using any knowledge about the independent component and the mixing matrix, or the observed signal x (t ) To estimate the restoration matrix W.

  As a signal source (original signal) of the plurality of observation signals received by the signal processing device 20 in the reception step (step S10), the X axis direction caused by the impact in the arrow A direction by the weight 22 as described above is used. It is considered that there are vibrations of the bridge pier 12, other measurement noise components, components due to vibrations of other components of the bridge 10 (also noise components), and the like. Signals from these signal sources are received as a plurality of observation signals by a plurality of sensors 14a, etc., and the received plurality of observation signals are processed by independent component analysis to extract one vibration including the natural vibration component of the pier 12 To do.

  Subsequently, one or more independent components extracted in the extraction step (step S12) are subjected to spectrum analysis to acquire the natural frequency of the pier 12 (natural frequency acquisition step, step S14). In the first embodiment, one vibration including the natural vibration component of the pier 12 is extracted, and the vibration is spectrally analyzed to obtain the highest frequency as the natural frequency of the pier 12.

  Based on the comparison between the natural frequency of the pier 12 acquired in the natural frequency acquisition step (step S14) and a predetermined reference value, the strength deterioration of the pier 12 is diagnosed (diagnosis step, step S16). The predetermined reference value is a standard value of the natural frequency acquired when the pier 12 is healthy, and the strength deterioration based on Table 1 is obtained by the soundness index (α) obtained by the following formula 6. It is preferable to make a diagnosis. For soundness index (α) and Table 1, refer to “Railway Technical Research Institute,“ Standards and Explanation of Building Maintenance Management (Steel Structures) ”, published in September 1987”.

  As shown in Table 1, when the soundness index is lower than 0.7, the determination rank is A1, and “a detailed inspection is performed and measures are taken into consideration”. When the soundness index is higher than 0.7 and lower than 0.85, the determination rank is A2, and “the progress of deformation such as inclination and scouring is monitored”. On the other hand, when the soundness index is 0.85 or higher, the determination rank is B or higher, and “currently there are few problems and it is considered sound”. A soundness index is obtained from the natural frequency of the pier 12 acquired in the natural frequency acquisition step (step S14) and the standard value of the natural frequency recorded in the memory of the signal processing device 20 in advance. And the content of Table 1 recorded in the memory of the signal processing device 20 in advance can automatically diagnose the strength deterioration of the pier 12. That is, it is possible to objectively and quantitatively perform maintenance management and diagnosis methods for large buildings such as the bridge 10.

  In the above-mentioned diagnosis step (step S16), the natural frequency of the pier 12 acquired in the natural frequency acquisition step (step S14) is acquired over a plurality of times, and the maximum or minimum of the plurality of natural frequencies is obtained. By performing comparison with the predetermined reference value as described above using the natural frequency, it is possible to diagnose the strength deterioration of the pier 12.

  As described above, the cause of the vibration of the pier 12 may include a case including a case where the vehicle 24 or 26 or the like travels in addition to a case where the weight 22 causes an impact in the arrow A direction. In such a case, the receiving step (step S10) may receive a signal generated by the vibration of the pier 12 by the sensor 14a or the like from the time when the value measured by the strain gauge 16 exceeds a predetermined value. it can. The position where the strain gauge 16 is installed is a predetermined position at one or more points around the pier 12 or the pier 12, and is different from a plurality of predetermined positions where the sensors 14a and the like are installed. It is assumed that the strain gauge 16 and the signal processing device 20 are connected by the predetermined method described above. As described above, signals that can be constantly monitored in real time by the signal processing device 20 connected to the sensor 14a and the strain sensor 16 using daily and normal vibrations due to traveling of the vehicle 24 or 26, etc., instead of the impact due to the weight 22. A processing method or the like can be provided.

  Next, a simulation performed for confirming the validity of the signal processing method of the present invention will be described.

1. Finite Element Method (Finite
Diagnosis simulation of bridge piers by Element Method: FEM 1.1 FEM and analysis program FEM is a numerical analysis method for solving differential equations approximately, and turns objects with complex shapes and properties into simple small parts. It approximates by dividing and tries to predict the whole behavior. Examples of results obtained by FEM analysis include stress, displacement (strain), vibration characteristics, sound characteristics, thermal characteristics, and the like. The FEM calculation process divides the structure into meshes composed of “elements” and “nodes”, models them, solves the balance equation with the node displacement as an unknown, and calculates the stress of each element from the node displacement. It is to do. In this simulation, MSC MSC (registered trademark). Marc was used. MSC. Marc is the most highly regarded general-purpose program for nonlinear finite element analysis since the mid-1970s. It can design complex structures, incorporate geometric behavior and nonlinear behavior of materials, It has the advantage that it can be used on most computers from stations to supercomputers.

1.2 Bridge model A bridge model was created as an example of a large structure. Fig. 3 is a map showing the location of the Aarashi Bridge in Kitakyushu City's Kokura Kita Ward, the target bridge used in the analysis (Source: http://map.yahoo.co.jp/pl?nl=33.49.50.908&el) = 130.52.41.438 & la = 1 & sc = 4 & CE.x = 244 & CE.y = 103). FIG. 4B is a full view (bridge surface) of the Seiryo Bridge, and FIG. 4C is a diagram showing the pier of the Seiryo Bridge. As shown in FIGS. 4A and 4B, the coordinate axes are defined as the X axis in the horizontal direction, the Y axis in the vertical direction, and the Z axis in the side surface direction (the direction along the river) of the bridge. Hereinafter, coordinate axes are used in the same way in each figure. Table 2 gives an overview of the structure of Seiryo Bridge.

  5A to 5D show bridge models created by FEM (MSC. Marc). The structural material for the upper part of the bridge and the structural material for the lower part were set to concrete. The main girder structural material was set to steel. Table 3 shows the detailed material parameters.

  For the bridge model shown above, the bridge vibration generated by the three methods of bridge vibration due to the impact of the weight 22, bridge vibration due to wind power, and bridge vibration due to the vehicle, In the case of deterioration, in the case of scouring, how the vibration state of the bridge changes was analyzed by a computer using the FEM analysis program.

1.3 Vibration analysis method and analysis result by impact of weight 22 FIG. 6 shows an outline of a vibration test method by impact of the weight 22. In FIG. 6, the same reference numerals as those in FIG. As shown in FIG. 6, the vibration test method by the impact of the weight 22 is performed by hitting the beam portion or the column (the pier 12) of the bridge 10 about 10 to 20 times with the weight 22 of about 200 to 300N. The response waveform generated by the vibration of 12 is measured by the sensor 14a or the like and recorded in the PC 20. Perform Fourier analysis of the recorded response waveform to obtain the Fourier spectrum. The soundness index (α) is obtained from the measured natural frequency obtained in this way and the standard value of the natural frequency (the natural frequency set from existing measurement data) or the design natural frequency, and the soundness of the pier is obtained. Determine. In the computer simulation, there was no noise, so the pier 12 was hit only once with a load of 300N. The hit | damage site | part was made into two places with the height of 5.5 m of the pier 12 and the height of 4.5 m of the pier 12. FIG. 7 (A) shows a blow to the site P5.5 having a height of 5.5 m of the pier 12, and FIG. 7 (B) shows a blow to the site P4.5 having a height of 4.5 m of the pier 12.

1.3.1 When the Bridge 10 is Healthy The analysis result of hitting the pier 12 with the weight 22 when the bridge 10 is healthy will be described. 8 (A) to 8 (E), a portion P5.5 having a height of 5.5 m of the pier 12 is hit by the weight 22 and is respectively 0.1 seconds, 0.2 seconds, 0.3 seconds, 0 The displacement contour diagram of the pier 12 after the elapse of 4 seconds and 0.5 seconds is shown. 8A to 8E, the magnitude of the displacement due to vibration increases as it goes up (becomes brighter) and goes down (becomes darker), as shown in the left color graph in each figure. Get smaller. The unit of displacement is mm. The same applies to each displacement contour diagram. As shown in FIGS. 8A to 8E, it can be seen that the displacement increases as time elapses.

  FIG. 9 shows a displacement history plot of the pier 12 after hitting the weight 22 on a portion P5.5 having a height of 5.5 m of the pier 12. In FIG. 9, the horizontal axis represents time, and the vertical axis represents the amount of displacement. The same applies to the drawings showing the displacement history plots. The color coding of the plots in FIG. 9 indicates the location in the pier 12 (installation of the sensor 14a etc.). As shown in the observation signals by the sensors 14a and the like in FIG. As a result, when the weight 22 is received at the site P5.5 having a height of 5.5 m of the pier 12, the maximum displacement amount of the pier 12 is 0.00001553 mm.

  FIG. 10 shows an independent vibration response extracted from the observation signal, that is, an independent component analysis result. 10, the horizontal axis and the vertical axis are the same as those in FIG. Hereinafter, the same applies to the drawings showing the results of independent component analysis. FIG. 11 shows the spectrum analysis results of the independent components shown in FIG. In FIG. 11, the horizontal axis represents frequency (Hz), and the vertical axis represents displacement. The same applies to the drawings showing the results of spectrum analysis of each independent component. As shown in FIG. 11, the natural frequency of the pier 12 is approximately 0.2184 Hz.

  The simulation analysis was similarly performed for the case where the portion P4.5 having a height of 4.5 m of the pier 12 was hit by the weight 22. Each figure of a displacement contour diagram, a displacement history plot, an independent component analysis result, and an independent component spectrum analysis result is omitted. As a result, the maximum displacement of the bridge pier 12 is 0.0000145 mm when the weight P is received at a portion P4.5 having a height of 4.5 m of the pier 12, compared with the case of a height of 5.5 m. The maximum displacement amount of 12 became smaller. The natural frequency of the pier 12 was about 0.2184 Hz, which was the same as the case of a height of 5.5 m. Therefore, when the pier 12 is healthy, the maximum displacement amount of the pier 12 increases with a change in the height of the position of impact by the weight 22, but the natural frequency of the pier almost coincides.

1.3.2 When the bridge 10 is structurally deteriorated The portion of the weight 22 that is struck is 5.5 m and 4.5 m in height as in the case of soundness, but the Young's modulus of the concrete material of the material parameter It was changed from 2.7E04N / mm ² to 2.5E04N / mm ^2. 12 (A) to 12 (E), a portion P5.5 having a height of 5.5 m of the pier 12 is hit by the weight 22 and is respectively 0.1 seconds, 0.2 seconds, 0.3 seconds, 0 The displacement contour diagram of the pier 12 after the elapse of 4 seconds and 0.5 seconds is shown. FIG. 13 shows a displacement history plot of the pier 12 after hitting the weight 22 on a portion P5.5 having a height of 5.5 m of the pier 12. As a result, the maximum displacement amount of the pier 12 is 0.00001793 mm when the weight 22 is received at the site P5.5 having a height of 5.5 m of the pier 12. Compared with the result in the case of soundness, the maximum variable of the pier 12 becomes large. FIG. 14 shows the result of independent component analysis. FIG. 15 shows the spectral analysis results of the independent components shown in FIG. As shown in FIG. 15, the natural frequency of the pier 12 is approximately 0.1953 Hz. The natural frequency of the pier 12 is smaller than the result in the case of soundness.

  The simulation analysis was similarly performed for the case where the portion P4.5 having a height of 4.5 m of the pier 12 was hit by the weight 22. Each figure of a displacement contour diagram, a displacement history plot, an independent component analysis result, and an independent component spectrum analysis result is omitted. As a result, the maximum displacement of the bridge pier 12 is 0.00001615 mm when the weight 22 is received at a part P4.5 having a height of 4.5 m of the bridge pier 12. The variable becomes larger. The natural frequency of the pier 12 is approximately 0.1953 Hz, and the natural frequency of the pier 12 is smaller than the result in the case of soundness. Therefore, when the bridge 10 is aged, the maximum displacement amount of the pier 12 is increased, but the natural frequency of the pier 12 is decreased.

1.3.3 When Scouring Occurs Next, when scouring occurs on the pier 12, the results of an analysis in which the pier 12 is struck with the weight 22 will be described. FIG. 16 is a diagram for explaining scouring. As shown in FIG. 16, scouring is a phenomenon in which the riverbed upstream of the pier 12 (left side in FIG. 16) is dug. Scouring is a serious problem that affects the safety of structures. When there is scouring, the portion hit by the weight 22 is the same position as in the case of soundness.

  17 (A) to 17 (E), a portion P5.5 having a height of 5.5 m of the pier 12 is hit by the weight 22 and is respectively 0.1 seconds, 0.2 seconds, 0.3 seconds, 0 The displacement contour diagram of the pier 12 after the elapse of 4 seconds and 0.5 seconds is shown. FIG. 18 shows a displacement history plot of the pier 12 after hitting the weight 22 on a portion P5.5 having a height of 5.5 m of the pier 12. As a result, when the weight 22 is received at the site P5.5 having a height of 5.5 m of the pier 12, the maximum displacement amount of the pier 12 is 0.00001799 mm. Compared with the result in the case of soundness, the maximum variable of the pier 12 becomes large. FIG. 19 shows the result of independent component analysis. FIG. 20 shows the spectrum analysis results of the independent components shown in FIG. As shown in FIG. 20, the natural frequency of the pier 12 is about 0.2050 Hz. The natural frequency of the pier 12 is smaller than the result in the case of soundness.

  The simulation analysis was similarly performed for the case where the portion P4.5 having a height of 4.5 m of the pier 12 was hit by the weight 22. Each figure of a displacement contour diagram, a displacement history plot, an independent component analysis result, and an independent component spectrum analysis result is omitted. As a result, the maximum displacement of the pier 12 is 0.00001587 mm when the weight 22 is received at the part P4.5 having a height of 4.5 m of the pier 12, and the maximum of the pier is larger than the result in a healthy case. The variable becomes larger. The natural frequency of the pier 12 is approximately 0.2050 Hz, and the natural frequency of the pier 12 is smaller than the result in the case of soundness. Therefore, when scouring occurs in the bridge 10, the maximum displacement of the pier 12 is increased, but the natural frequency of the pier 12 is decreased. Table 4 summarizes the results of vibration analysis due to the impact of the weight 22.

1.4 Vibration analysis method and analysis result due to impact of wind force The micro vibration method always measures natural forces such as wind of the bridge 10 or minute vibrations caused by ground vibration as random vibrations. For this reason, it is suitable for the diagnosis of the bridge in service without requiring a vibration means. Since the vibration amplitude is small, it is necessary to consider the amplitude dependency, temperature dependency, etc. of the measurement. The method for analyzing natural vibration characteristics from micro vibrations is based on the same concept as the shock vibration method, assuming that the external force is steady random.

  FIG. 21A shows a case where the bridge receives wind in the Z direction in the computer simulation analysis, FIG. 21B shows a case where the bridge receives wind in the X direction, and FIG. Indicates the boundary condition.

1.4.1 When the Bridge 10 is Healthy FIGS. 22 (A) to (E) show that when the entire bridge 10 receives a wind velocity in the Z direction at 10 m / s, 0.1 seconds and 0.2 seconds, respectively. The displacement contour diagram of the pier 12 after elapse of seconds, 0.3 seconds, 0.4 seconds, and 0.5 seconds is shown. FIG. 23 shows a displacement history plot after the bridge 10 as a whole receives wind speed in the Z direction at 10 m / s. As a result, when the entire bridge 10 receives a wind speed in the Z direction at 10 m / s, the maximum displacement of the pier 12 is 0.002366 mm. FIG. 24 shows the result of independent component analysis. FIG. 25 shows the spectrum analysis results of the independent components shown in FIG. As shown in FIG. 25, the natural frequency of the pier 12 is about 0.2343 Hz.

  The simulation analysis was similarly performed when the bridge 10 as a whole received wind speed in the Z direction at 20 m / s, 30 m / s, and 40 m / s. Each figure of a displacement contour diagram, a displacement history plot, an independent component analysis result, and an independent component spectrum analysis result is omitted. As a result, when the bridge 10 as a whole was subjected to the wind speed in the Z direction at 20 m / s, 30 m / s, and 40 m / s, the maximum displacement of the pier 12 was 0.009462 mm, 0.02129 mm, and 0.03785 mm, respectively. It was. Accordingly, the wind speed increases and the maximum displacement of the pier 12 also increases. As a result of spectrum analysis, when the bridge 10 as a whole is subjected to a wind speed in the Z direction at 20 m / s, 30 m / s, and 40 m / s, the natural frequency of the pier 12 is 0.2343 Hz.

  A simulation was made of how the vibration of the bridge 10 changes when the wind speed is gradually increased from 0 m / s to 40 m / s and then decreased. Each figure of a displacement contour diagram, a displacement history plot, an independent component analysis result, and an independent component spectrum analysis result is omitted. As a result, the maximum displacement of the pier 12 is 0.02777 mm. Compared to the result of the bridge 10 receiving the same wind speed of 40 m / s in 10 seconds, the maximum displacement of the pier is small. As a result of spectral analysis, the natural frequency of the pier 12 is 0.2441 Hz. Compared with the result of the bridge 10 receiving the same wind speed in 10 seconds, the natural frequency of the pier is not much different.

  FIGS. 26 (A) to (E) show 0.1 seconds, 0.2 seconds, 0.3 seconds, and 0.4 seconds, respectively, when the bridge 10 as a whole is subjected to the wind velocity in the X direction at 10 m / s. The displacement contour figure of the bridge pier 12 after 0.5 second elapses is shown. FIG. 27 shows a displacement history plot after the bridge 10 as a whole receives wind speed in the X direction at 10 m / s. As a result, when the entire bridge 10 receives a wind speed in the X direction at 10 m / s, the maximum displacement of the bridge pier 12 is 0.006591 mm. FIG. 28 shows the results of independent component analysis. FIG. 29 shows the spectrum analysis results of the independent components shown in FIG. As shown in FIG. 29, the natural frequency of the pier 12 is approximately 0.371 Hz.

  The simulation analysis was similarly performed when the bridge 10 as a whole received wind velocity in the X direction at 20 m / s, 30 m / s, and 40 m / s. Each figure of a displacement contour diagram, a displacement history plot, an independent component analysis result, and an independent component spectrum analysis result is omitted. As a result, when the bridge 10 as a whole was subjected to wind velocity in the X direction at 20 m / s, 30 m / s, and 40 m / s, the maximum displacement of the pier 12 was 0.002636 mm, 0.0005932 mm, and 0.01955 mm, respectively. It was. Accordingly, the wind speed increases and the maximum displacement of the pier 12 also increases. As a result of spectrum analysis, when the bridge 10 as a whole is subjected to the wind speed in the Z direction at 20 m / s, 30 m / s, and 40 m / s, the natural frequency of the pier 12 is 0.371 Hz.

  A simulation was made of how the vibration of the bridge 10 changes when the wind speed is gradually increased from 0 m / s to 40 m / s and then decreased. Each figure of a displacement contour diagram, a displacement history plot, an independent component analysis result, and an independent component spectrum analysis result is omitted. As a result, the maximum displacement of the pier 12 is 0.005762 mm. Compared to the result of the bridge 10 receiving the same wind speed of 40 m / s in 10 seconds, the maximum displacement of the pier is small. As a result of the spectrum analysis, the natural frequency of the pier 12 is 0.1333 Hz. Compared with the result of the bridge 10 receiving the same wind speed in 10 seconds, the natural frequency of the pier is small.

1.4.2 When Bridge 10 is Degraded The Young's modulus of the concrete material of the material parameter was changed from 2.7E04 N / mm ² to 2.5E04 N / mm ² . FIGS. 30A to 30E show 0.1 seconds, 0.2 seconds, 0.3 seconds, and 0.4 seconds, respectively, when the entire bridge 10 is subjected to a wind speed in the Z direction at 40 m / s. The displacement contour figure of the bridge pier 12 after 0.5 second elapses is shown. FIG. 31 shows a displacement history plot after the bridge 10 as a whole has received a wind speed in the Z direction at 40 m / s. As a result, when the entire bridge 10 receives a wind speed in the Z direction at 40 m / s, the maximum displacement amount of the pier 12 is 0.04413 mm. When the bridge 10 is healthy, the maximum displacement of the bridge pier is larger than the result of the bridge 10 receiving and analyzing the wind speed in the Z direction of 40 m / s. FIG. 32 shows the result of independent component analysis. FIG. 33 shows the spectrum analysis results of the independent components shown in FIG. As shown in FIG. 32, the natural frequency of the pier 12 is approximately 0.2246 Hz. When the bridge 10 is healthy, the natural frequency of the pier 12 is smaller than the analysis result of the bridge 10 receiving wind speed of 40 m / s in the Z direction.

  FIGS. 34 (A) to (E) show 0.1 seconds, 0.2 seconds, 0.3 seconds, and 0.4 seconds, respectively, when the bridge 10 as a whole is subjected to the wind velocity in the X direction at 40 m / s. The displacement contour figure of the bridge pier 12 after 0.5 second elapses is shown. FIG. 35 shows a displacement history plot after the bridge 10 as a whole receives wind speed in the X direction at 40 m / s. As a result, when the entire bridge 10 receives a wind velocity in the X direction at 40 m / s, the maximum displacement of the pier 12 is 0.01226 mm. FIG. 36 shows the result of independent component analysis. FIG. 37 shows the spectrum analysis results of the independent components shown in FIG. As shown in FIG. 37, the natural frequency of the pier 12 is approximately 0.3516 Hz. When the bridge 10 is healthy, the natural frequency of the pier 12 is smaller than the analysis result of the pier 12 receiving the wind speed of 40 m / s in the X direction. Therefore, when the bridge 10 is deteriorated, the maximum displacement amount of the pier 12 is increased, and the natural frequency of the pier is decreased.

1.4.3 When scouring occurs Next, when scouring occurs on the pier 12, the bridge 10 analyzed the wind speed in the Z direction, X direction, 40 m / s for 10 seconds and explained the results. To do. FIGS. 38 (A) to (E) are respectively 0.1 seconds, 0.2 seconds, 0.3 seconds, and 0.4 seconds when the entire bridge 10 is subjected to a wind speed in the Z direction at 40 m / s. The displacement contour figure of the bridge pier 12 after 0.5 second elapses is shown. FIG. 39 shows a displacement history plot after the bridge 10 as a whole has received a wind speed in the Z direction at 40 m / s. As a result, when the entire bridge 10 receives a wind speed in the Z direction at 40 m / s, the maximum displacement of the pier 12 is 0.04381 mm. When the bridge 10 is healthy, the maximum displacement amount of the pier 12 is larger than the analysis result of the pier receiving the wind speed of 40 m / s in the Z direction. FIG. 40 shows the results of independent component analysis. FIG. 41 shows the spectrum analysis results of the independent components shown in FIG. As shown in FIG. 41, the natural frequency of the pier 12 is approximately 0.2246 Hz. When the bridge 10 is healthy, the natural frequency of the pier 12 is smaller than the analysis result of the bridge 10 receiving wind speed of 40 m / s in the Z direction.

  42 (A) to 42 (E) show the case where the entire bridge 10 is subjected to the wind speed in the X direction at 40 m / s, 0.1 seconds, 0.2 seconds, 0.3 seconds and 0.4 seconds, respectively. The displacement contour figure of the bridge pier 12 after 0.5 second elapses is shown. FIG. 43 shows a displacement history plot after the bridge 10 as a whole has received a wind velocity in the X direction at 40 m / s. As a result, when the entire bridge 10 receives a wind velocity in the X direction at 40 m / s, the maximum displacement of the pier 12 is 0.01267 mm. When the bridge 10 is healthy, the maximum displacement of the bridge pier is larger than the analysis result of the bridge pier 12 receiving wind speed of 40 m / s in the X direction. FIG. 44 shows the result of independent component analysis. FIG. 45 shows the spectral analysis results of the independent components shown in FIG. As shown in FIG. 45, the natural frequency of the pier 12 is approximately 0.2246 Hz. When the bridge 10 is healthy, the natural frequency of the pier 12 is smaller than the analysis result of the pier 12 receiving the wind speed of 40 m / s in the X direction. Therefore, when the pier 12 is scoured, the maximum displacement is increased and the natural frequency is decreased. Table 5 summarizes the results of vibration analysis based on wind speed.

1.5 Vehicle vibration analysis method and analysis results The vehicle running experiment is an experiment to measure the stress, displacement, acceleration, etc. of the structure generated during running of the test vehicle in order to evaluate the strength and function of the bridge 10. . The vehicle running method uses random vibrations when a test vehicle is run on a normal road surface at a constant speed, when it is run with a step on the road surface, when several vehicles are run along with it, and when running a general vehicle. There is a case to measure. When measuring the damped free vibration, the residual vibration immediately after traveling the vehicle is measured. In the computer simulation, it is assumed that a vehicle having a load of 3 t passes through the bridge 10 at a speed of 40 km / h, and scouring occurs when the bridge is healthy or structural deterioration occurs, as in the impact test using the weight 22. For the case, we analyzed how the vibration state of the bridge 10 changed when the vehicle passed.

1.5.1 When the Bridge 10 is Healthy FIGS. 46A to 46E show 0.1 seconds, 0.2 seconds, and 0 when a 3 ton vehicle passes the bridge 10 at 40 km / h, respectively. The displacement contour diagram of the pier 12 after the elapse of 3 seconds, 0.4 seconds, and 0.5 seconds is shown. FIG. 47 shows a displacement history plot when a 3t vehicle passes through the bridge 10 at 40 km / h. As a result, when a 3t vehicle passes through the bridge 10 at 40 km / h, the maximum displacement of the pier 12 is 0.00006289 mm. FIG. 48 shows the result of independent component analysis. FIG. 49 shows the spectrum analysis results of the independent components shown in FIG. As shown in FIG. 48, the natural frequency of the pier 12 is approximately 0.2083 Hz.

1.5.2 When the bridge 10 is deteriorated The Young's modulus of the concrete material of the material parameter was changed from 2.7E04 N / mm ² to 2.5E04 N / mm ² . 50A to 50E show 0.1 seconds, 0.2 seconds, 0.3 seconds, 0.4 seconds, 0. 3 seconds when a 3t vehicle passes through the bridge 10 at 40 km / h, respectively. A displacement contour diagram of the pier 12 after the elapse of 5 seconds is shown. FIG. 51 shows a displacement history plot when a 3t vehicle passes through the bridge 10 at 40 km / h. As a result, when a 3 ton vehicle passes through the bridge 10 at 40 km / h, the maximum displacement amount of the pier 12 is 0.00007244 mm. Compared with the result of analysis when the bridge 10 is healthy, the maximum displacement amount of the pier 12 is increased. FIG. 52 shows the results of independent component analysis. FIG. 53 shows the spectrum analysis results of the independent components shown in FIG. As shown in FIG. 53, the natural frequency of the pier 12 is about 0.1833 Hz. Compared with the result of analysis when the bridge 10 is healthy, the natural frequency of the pier 12 is small.

1.5.3 When Scouring Occurs FIGS. 54A to 54E show 0.1 seconds, 0.2 seconds, and 0 seconds when a 3 ton vehicle passes through the bridge 10 at 40 km / h, respectively. The displacement contour diagram of the pier 12 after the elapse of 3 seconds, 0.4 seconds, and 0.5 seconds is shown. FIG. 55 shows a displacement history plot when a 3t vehicle passes through the bridge 10 at 40 km / h. As a result, when a 3t vehicle passes through the bridge 10 at 40 km / h, the maximum displacement amount of the pier 12 is 0.00006946 mm. Compared with the result of analysis when the bridge 10 is healthy, the maximum displacement amount of the pier 12 is increased. FIG. 56 shows the results of independent component analysis. FIG. 57 shows the spectrum analysis results of the independent components shown in FIG. As shown in FIG. 57, the natural frequency of the pier 12 is approximately 0.1917 Hz. Compared with the result of analysis when the bridge 10 is healthy, the natural frequency of the pier 12 is small. Therefore, when the pier 12 is scoured, the maximum displacement amount is increased and the natural frequency is decreased. Table 6 summarizes the results of vibration analysis by the vehicle.

1.6 Results From the results of computer simulation analysis, the vibration behavior of the entire structure of the bridge 10 was clarified by vibrations caused by external forces such as impact, wind pressure, and vehicle vibration caused by the weight 22. These are summarized below.

(1) As a result of the vibration analysis by the impact of the weight 22, the maximum displacement amount of the pier 12 increases with a change in the height of the position of the impact of the weight 22, and the natural frequency of the pier 12 almost matches. . Therefore, it is preferable that the sensors 14a and the like are arranged at two or more positions between the upper part and the lower part of the pier 12. When the material deteriorates with age, the maximum displacement of the pier 12 increases, but the natural frequency of the pier 12 decreases. When scouring occurs, the maximum displacement of the pier 12 increases and the natural frequency of the pier 12 decreases.

(2) As a result of the vibration analysis by wind power, the maximum displacement amount of the pier 12 increases as the wind speed increases, but the natural frequency of the pier is approximately the same. When the material deteriorates with age, the maximum displacement of the pier 12 increases and the natural frequency of the pier 12 decreases. When scouring occurs, the maximum displacement of the pier 12 increases and the natural frequency of the pier decreases.

(3) When the material deteriorates with the years as a result of the vibration analysis by the vehicle, the maximum displacement amount of the pier 12 increases and the natural frequency of the pier 12 decreases. When scouring occurs, the maximum displacement of the pier 12 increases and the natural frequency of the pier 12 decreases.

  From the above, as a result of computer simulation analysis, one or more extracted independent components are extracted by processing signals measured at a plurality of locations (locations such as the sensor 14a) of the pier 12 by independent component analysis. It was confirmed that the natural frequency of the pier 12 can be obtained by spectral analysis of the independent components. It was also confirmed that the natural frequency changed due to deterioration of the pier 12 (change in strength) and occurrence of scouring. By obtaining the soundness index (α) based on the comparison between the acquired natural frequency of the pier 12 and the standard value of the natural frequency, it is possible to diagnose the strength deterioration of the pier 12 based on the soundness index (α). . That is, the strength deterioration of the pier 12 can be diagnosed by the signal processing method of the present invention.

2. Confirmation by field experiment 2.1 Field experiment method The measuring instrument uses the speedometer and accelerometer described above. The position of the measuring point is measured with an accelerometer at the bridge shaft perpendicular direction and the vertical direction at the top end of the pier 12 where the natural frequency and vibration mode of the pier 12 can be grasped, and at the middle and lower ends of the bridge shaft at right angles. At the same time, two components in the direction perpendicular to the bridge axis and the vertical direction at the top of the pier 12 are measured for verification by the speedometer used in the conventional shock vibration test. In order to specify the natural vibration of the superstructure and the vehicle running vibration, which are noises in detecting the natural vibration of the pier 12, the vertical component at the center of the front and rear of the pier 12 to be measured and on the fulcrum (on the pier 12) is used as the pier 12 In addition, in order to confirm the behavior of the bridge 10 and the influence on the vibration, two components of the bridge axis direction and the vertical direction at both ends of the bridge 10 are measured.

  58 is a diagram showing a measurement outline of disturbance vibration measurement of the P1 pier 12, and FIG. 59 is a cross-sectional view of the P1 pier 12 taken along 1-1. 58 and 59 denoted by the same reference numerals as those in FIG. 58 and 59, 1ch such as “1ch: A-1z” is a channel, and A-1z is a sensor No. The colored square mark is the acceleration sensor (vertical), the triangular mark is the acceleration sensor (bridge axis), the white circle mark is the speed sensor (bridge axis vertical), the colored white circle mark is the acceleration sensor (bridge axis vertical), and the white square mark is A speed sensor (vertical) is shown. FIG. 60 is a diagram showing an outline of installation of the strain gauge 16, and FIG. 61 is a diagram showing an outline of installation of the acceleration sensor 14a and the like. Table 7 shows a list of measurement points of the pier 12 shown in FIGS.

2.2 Analysis of on-site experiment results The results of natural frequencies extracted by independent component analysis from vibrations caused by vehicle running on-site will be explained. Measurements were made by pasting a 12-channel acceleration sensor and a 2-channel speed sensor. In this specification, the vibration frequency actually measured by some of the sensors will be described.

2.2.1 Vibrations caused by large vehicles First, the results of independent component analysis of vibrations caused by the passage of large vehicles will be described. Specifically, the center of one span of one channel of the accelerometer, the end of one span of two channels (on the P1 pier 12) (vertical), the center of two channels of four channels (vertical), the speedometer The 13 channel P1 pier 12 top edge central velocity (perpendicular to the bridge axis) and 14 channels of P1 pier 12 top edge center velocity (vertical) were received and extracted by independent component analysis. The frequency is compared and the validity of the analysis method (the signal processing method of the present invention) is verified.

  FIG. 62 shows that the vibration caused by a large vehicle is the center of one span of one channel of the accelerometer, the end of one span of two channels (on the P1 pier 12) (vertical), and the center of two spans of four channels (vertical). Shows vibrations taken from In FIG. 62, the horizontal axis represents time, and the vertical axis represents the amount of displacement. The same applies hereinafter. FIG. 63 shows the result of independent component analysis of the vibration shown in FIG. FIG. 64 shows the spectrum analysis result of the independent component shown by FIG. As a result, the natural frequency of the extracted bridge 12 is 4.0527 Hz.

  FIG. 65 is also taken from the 13-channel P1 pier 12 top center speed (perpendicular to the bridge axis) of the speedometer and the 14-channel P1 pier 12 top center speed (vertical) when a large vehicle passes. Shows vibration. FIG. 66 shows the result of independent component analysis of the vibration shown in FIG. FIG. 67 shows the spectrum analysis result of the independent component shown by FIG. As a result, the natural frequency of the extracted bridge 12 is 3.4667 Hz. There is no significant difference compared to the natural frequency extracted from the accelerometer.

2.2.2 Vibration by 2t dump truck Next, the result of independent component analysis of the vibration generated by the passage of the 2t dump truck will be described. The measurement points are the same as for large vehicles. FIG. 68 shows that the vibration caused by the 2t car is the center of one axis of one channel of the accelerometer, the end of one channel of two channels (on the P1 pier 12) (vertical), and the center of two channels of four channels (vertical). Shows vibrations taken from FIG. 69 shows the result of independent component analysis of the vibration shown in FIG. FIG. 70 shows the spectral analysis results of the independent components shown by FIG. As a result, the natural frequency of the extracted bridge 12 is 4.0527 Hz.

  FIG. 71 is also taken from the 13-channel P1 pier 12 top center speed (perpendicular to the bridge axis) of the speedometer and the 14-channel P1 pier 12 top center speed (vertical) when the 2t car passes. Shows vibration. FIG. 72 shows the result of independent component analysis of the vibration shown in FIG. FIG. 73 shows the spectrum analysis results of the independent components shown by FIG. As a result, the natural frequency of the extracted bridge 12 is 4.004 Hz. It is almost the same as the natural frequency extracted from the accelerometer.

2.2.3 Vibration by 4t dump truck Next, the result of independent component analysis of vibration generated by the passage of the 4t dump truck will be described. The measurement points are the same as in the case of large vehicles and 2t dump vehicles. In FIG. 74, the vibration caused by the 4t car is the center of one span of one channel of the accelerometer, the end of one span of two channels (on the P1 pier 12) (vertical), and the center of two channels of four channels (vertical). Shows vibrations taken from FIG. 75 shows the result of independent component analysis of the vibration shown in FIG. FIG. 76 shows the spectrum analysis results of the independent components shown by FIG. As a result, the natural frequency of the extracted bridge 12 is 4.0527 Hz.

  FIG. 77 is similarly taken from the 13-channel P1 pier 12 top center speed (perpendicular to the bridge axis) and the 14-channel P1 pier 12 top speed (vertical) of the speedometer when a 4t car passes. Shows vibration. FIG. 78 shows the result of independent component analysis of the vibration shown in FIG. FIG. 79 shows the spectrum analysis results of the independent components shown by FIG. As a result, the natural frequency of the extracted bridge 12 is 4.0527 Hz. Compared with the natural frequency extracted from the accelerometer, it was almost the same.

2.3 Results and discussion Table 8 summarizes the results of field experiments.

  As shown in Table 1, it has been found that the natural frequency is not so different between large vehicles, 2t dump vehicles, and 4t dump vehicles. When comparing the natural frequency based on the vibration data actually obtained by field experiments and the natural frequency obtained by computer simulation analysis, there is a slight difference in the natural frequency of the pier. The concrete structure is a composite of concrete and reinforcing materials such as reinforcing bars and steel frames. However, since the structural material of the upper part and the lower part of the bridge 10 is set to concrete when performing computer simulation, the strength and rigidity of the bridge 10 are It seems that the cause is that it is lower than the actual P1 bridge 10. Therefore, it is considered that the difference between the two is eliminated by bringing the boundary conditions, material parameters, and the like in the computer simulation closer to the actual situation of the P1 bridge 10.

  As described above, according to the signal processing method and the like of the present invention, a signal measured at a plurality of locations (locations such as the sensor 14a) of the pier 12 is processed by independent component analysis to extract one or more independent components and extracted. It has been confirmed through computer simulation and field experiments that the natural frequency of the pier 12 can be obtained by spectral analysis of one or more independent components. By obtaining the soundness index (α) based on the comparison between the acquired natural frequency of the pier 12 and the standard value of the natural frequency, it is possible to diagnose the strength deterioration of the pier 12 based on the soundness index (α). . That is, the strength deterioration of the pier 12 can be diagnosed by the signal processing method of the present invention.

3. Supplement on Noise In the above-described computer simulation analysis, the natural frequency of the bridge 10 was taken in a state where noise was not taken into consideration. However, there is noise when actually measuring on site. Therefore, we added noise to the vibration response obtained after computer simulation analysis and analyzed whether the natural frequency can be obtained by independent component analysis.

  FIG. 80A shows the vibration response in the absence of noise obtained after the computer simulation analysis. On the other hand, FIG. 80B shows a vibration response when random numbers 0 to 0.01 are added to the measured vibration response. When FIG. 80A and FIG. 80B are compared, the vibration waveforms are almost the same. When random numbers 0.03 to -0.03 were added and random numbers 0 to 0.1 were also examined, although the vibration waveform is slightly disturbed, there is no problem in measurement of the vibration waveform. .

  FIG. 81 (A) shows the result of spectral analysis of the vibration response of FIG. 80 (A), and FIG. 81 (B) shows the result of spectral analysis of the vibration response of FIG. 80 (B). Observing from the analysis results, the natural frequency is the same. Therefore, when the noise is small, the natural frequency of the bridge 10 can be measured effectively.

4). Supplement on Wireless Sensor As described above, it is preferable that the connection between the sensor 14a and the signal processing apparatus 20 is performed by a wireless sensor network. However, since it is difficult to simultaneously transmit the vibration responses captured by the wireless sensor network, it is necessary to transmit the measured vibration responses one by one. Therefore, it was verified whether or not the natural frequency of the bridge 10 was the same as the case where it was transmitted at the same time. That is, the case where the vibration response is transmitted simultaneously and the case where the vibration response is transmitted with a delay is compared to verify whether the natural frequency is changed. In the verification, the vibration response measured by the 3-channel sensor, 5-channel sensor, and 12-channel sensor was compared with the case where the vibration response was transmitted with a delay. FIGS. 82A and 82B each show the results of an analysis in which independent component analysis is performed on the case where the vibration response measured by the three-channel sensor is transmitted with a delay. Results for the case of 5-channel sensor and 12-channel are omitted. 83 (A) and 83 (B) show the results of spectral analysis of the results of FIGS. 82 (A) and 82 (B), respectively. As shown in FIGS. 83 (A) and 83 (B), it can be seen that even if the measured vibration response is transmitted with a delay, the natural frequency does not change as compared with the case where it is transmitted at the same time. It was. Therefore, even when the vibration response is transmitted with a delay, it has been verified that the influence on the calculation of the natural frequency of the bridge 10 is small. As a result, it has become clear that the connection between the sensor 14a and the signal processing device 20 is preferably based on a wireless sensor network.

  FIG. 84 is a block diagram showing an internal circuit 30 of the computer of the signal processing apparatus 20 that executes the computer program (signal processing program) of the present invention for realizing the above-described embodiment. As shown in FIG. 84, the CPU 31, ROM 32, RAM 33, image control unit 36, controller 37, input control unit 39 and external interface (I / F) unit 41 are connected to the bus 42. In FIG. 84, the above-described computer program of the present invention is recorded on a recording medium (including a removable recording medium) such as a ROM 32, a disk 38a, a CD-ROM, or a DVD 38n. The contents of Table 1 showing the standard value of natural frequency, the soundness index, and the determination described above are recorded on the disk 38a. The computer program of the present invention is loaded into the RAM 33 from the ROM 32 via the bus 42 or from a recording medium such as a disk 38a, CD-ROM or DVD 38n via the controller 37 via the bus 42. The input control unit 39 is connected to an input operation unit 40 such as a mouse and a keyboard to perform input control and the like. The VRAM 35 that is an image memory has a capacity corresponding to the data capacity of at least one screen of the display device 34, and the image control unit 36 has a function of converting the data in the VRAM 35 into image data and sending it to the display device 34. Have. The external I / F unit 41 has an input / output interface function when communicating with the sensor 14a and the like.

  As described above, the CPU 31 executes the computer program of the present invention to achieve the object of the present invention. The computer program can be supplied to the computer CPU 31 in the form of a recording medium such as a CD-ROM or DVD 38n as described above, and a recording medium such as a CD-ROM or DVD 38n on which the computer program is recorded is also recorded in this manner. It constitutes the invention. As a recording medium on which the computer program is recorded, for example, a memory card, a memory stick, an optical disk, an FD, or the like can be used in addition to the recording medium described above.

  In Example 1, the pier 12 which is a component of the bridge 10 was taken up and demonstrated as a target object. However, even when the entire bridge 10 is taken up as an object, the signal processing method of the present invention can be applied in the same manner, and the deterioration of the bridge 10 can be diagnosed. That is, the signal processing method of the present invention can be similarly applied not only to the components of the large structure but also to the large structure itself, and deterioration diagnosis of the large structure can be performed. In this case, the sensor 14a and the like are installed on the entire bridge 10 (large structure). Assuming a building as a large structure, when the vibration of the building includes a vehicle vibration, the strain gauge 16 may be installed not only on the building itself but also on the ground around the building.

  Examples of the use of the present invention include large structures such as bridges, buildings, tunnels, dams, road structures such as retaining walls, river structures such as locks and pipes, harbor structures, water and sewage facilities themselves, and configurations thereof. Application to elements.

It is a figure which shows the environment where the signal processing method by Example 1 of this invention, etc. are used. It is a flowchart which shows the flow of a process of the signal processing method or signal processing program in Example 1 of this invention. It is a map showing the position of the blue storm bridge in Kitakyushu City Kokurakita-ku, which is the target bridge used in the analysis. It is a figure which shows the whole view etc. of Aoi Arashi Bridge. It is a figure which shows the bridge model created by FEM (MSC.Marc). It is a figure which shows the outline | summary of the method of the vibration test by the impact of the weight. It is a figure (in the case of sound) which shows each blow to height 5.5m site P5.5 and height 4.5m site P4.5 of bridge pier 12. FIG. It is a displacement contour figure (in the case of sound) of the pier 12 as a result of being hit | damaged by the weight 22 in site | part P5.5 of 5.5 m in height of the pier 12. FIG. It is a figure which shows the displacement log | history plot of the bridge pier 12 after hitting the weight 22 to the site | part P5.5 of 5.5 m in height of the pier 12 (when healthy). It is a figure (in the case of sound) which shows the independent vibration response extracted from the observation signal, ie, an independent component analysis result. It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 10 (when healthy). It is a displacement contour figure (in the case of deterioration) of the pier 12 as a result of being hit | damaged by the weight 22 to the site | part P5.5 of 5.5 m in height of the pier 12. FIG. It is a figure which shows the displacement log | history plot of the bridge pier 12 after hitting the weight 22 to site | part P5.5 of 5.5 m in height of the pier 12 (in the case of deterioration). It is a figure which shows an independent component analysis result (in the case of deterioration). It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 14 (in the case of deterioration). It is a figure for demonstrating scouring. It is the displacement contour figure (in the case of scouring) of the pier 12 as a result of being hit | damaged by the weight 22 to the site | part P5.5 of 5.5 m in height of the pier 12. FIG. It is a figure (in the case of scouring) which shows the displacement history plot of the pier 12 after hitting the weight 22 to the site | part P5.5 of 5.5 m in height of the pier 12. FIG. It is a figure (in the case of scouring) which shows an independent component analysis result. It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 19 (in the case of scouring). It is a figure which shows the case where a bridge receives the wind of a Z direction. It is a displacement contour figure (in the case of sound) when the bridge 10 whole receives the wind speed of a Z direction at 10 m / s. It is a figure (in the case of sound) which shows the displacement history plot after the bridge 10 whole receives the wind speed of a Z direction at 10 m / s. It is a figure which shows an independent component analysis result (when healthy). It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 24 (when healthy). It is a displacement contour figure (in the case of sound) when the bridge 10 whole receives the wind speed of the X direction at 10 m / s. It is a figure which shows the displacement log | history plot after the bridge 10 whole receives the wind speed of a X direction at 10 m / s (when healthy). It is a figure (in the case of sound) which shows an independent component analysis result. It is a figure (in the case of sound) figure which shows the spectrum analysis result of the independent component shown by FIG. It is a displacement contour figure (in the case of deterioration) when the whole bridge 10 receives the wind speed of a Z direction at 40 m / s. It is a figure which shows the displacement log | history plot after the bridge 10 whole receives the wind speed of a Z direction at 40 m / s (in the case of deterioration). It is a figure which shows an independent component analysis result (in the case of deterioration). It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 32 (in the case of deterioration). It is a displacement contour figure (in the case of deterioration) when the bridge 10 whole receives the wind velocity of the X direction at 40 m / s. It is a figure which shows the displacement log | history plot after the bridge 10 whole receives the wind speed of a X direction at 40 m / s (in the case of deterioration). It is a figure which shows an independent component analysis result (in the case of deterioration). It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 36 (in the case of deterioration). It is a displacement contour figure (in the case of scouring) when the whole bridge 10 receives the wind speed of a Z direction at 40 m / s. It is a figure (in the case of scouring) which shows the displacement history plot after the bridge 10 whole receives the wind speed of a Z direction at 40 m / s. It is a figure (in the case of scouring) which shows an independent component analysis result. It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 40 (in the case of scouring). It is a displacement contour figure (in the case of scouring) when the whole bridge 10 receives the wind speed of the X direction at 40 m / s. It is a figure (in the case of scouring) which shows the displacement history plot after the bridge 10 whole receives the wind speed of a X direction at 40 m / s. It is a figure (in the case of scouring) which shows an independent component analysis result. It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 44 (in the case of scouring). It is a displacement contour figure (when healthy) when a 3 ton vehicle passes through the bridge 10 at 40 km / h. It is a figure which shows the displacement log | history plot when a 3t vehicle passes the bridge 10 at 40 km / h (when healthy). It is a figure which shows an independent component analysis result (when healthy). It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 48 (when healthy). It is a displacement contour figure (in the case of deterioration) when a 3t vehicle passes through the bridge 10 at 40 km / h. It is a figure (in the case of deterioration) which shows a displacement history plot when a 3t vehicle passes bridge 10 at 40 km / h. It is a figure which shows an independent component analysis result (in the case of deterioration). It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 52 (in the case of deterioration). ). It is a displacement contour figure (in the case of scouring) when a 3 ton vehicle passes through the bridge 10 at 40 km / h. It is a figure (in the case of scouring) which shows a displacement history plot when a 3t vehicle passes bridge 10 at 40 km / h. It is a figure (in the case of scouring) which shows an independent component analysis result. It is a figure which shows the spectrum analysis result of the independent component shown by FIG. 56 (in the case of scouring). It is a figure which shows the measurement outline | summary of the disturbance vibration measurement of P1 pier 12. It is 1-1 sectional drawing of P1 pier 12. As shown in FIG. It is a figure which shows the installation outline | summary of the strain gauge. It is a figure which shows the installation outline | summary of the acceleration sensor 14a. Vibration caused by a large vehicle is taken from the center of one span of one channel of the accelerometer and the end of one span of two channels (on the P1 pier 12) (vertical), and from the center of two spans of four channels (vertical). FIG. FIG. 63 is a diagram showing the result of independent component analysis of the vibration shown in FIG. 62. FIG. 64 is a diagram showing a spectrum analysis result of independent components shown by FIG. 63. It is a figure which shows the vibration which took from the P1 pier 12 top end center speed (bridge axis right angle) of 13 channels of a speedometer, and the P1 pier 12 top end center speed (vertical) of 14 channels when a large vehicle passed. . FIG. 66 is a diagram showing the result of independent component analysis of the vibration shown in FIG. 65. FIG. 67 is a diagram showing a spectrum analysis result of independent components shown by FIG. 66. Vibration caused by a 2t car is taken from the center of one channel of the accelerometer and the end of one channel of the two channels (on the P1 pier 12) (vertical), and from the center of the two channels of the four channels (vertical). FIG. FIG. 69 is a diagram showing the result of independent component analysis of the vibration shown in FIG. 68. It is a figure which shows the spectrum analysis result of the independent component shown by FIG. It is a figure which shows the vibration which took from the P1 pier 12 top end center speed (bridge axis right angle) of 13 channels of a speedometer, and the P1 pier 12 top end center speed (vertical) of 14 channels when a 2t car passed. . FIG. 72 is a diagram showing the result of independent component analysis of the vibration shown in FIG. 71. It is a figure which shows the spectrum analysis result of the independent component shown by FIG. Vibration caused by a 4t car is taken from the center of one channel of the 1 channel of the accelerometer and the end of one channel of the two channels (on the P1 pier 12) (vertical) and the center of the two channels of the four channels (vertical). FIG. FIG. 75 is a diagram showing a result of independent component analysis of vibration shown in FIG. 74. FIG. 76 is a diagram showing a spectrum analysis result of independent components shown by FIG. 75. It is a figure which shows the vibration which took from the P1 pier 12 top end center speed (bridge axis right angle) of 13 channels of a speedometer, and the P1 pier 12 top end center speed (vertical) of 14 channels when a 4t car passed. . FIG. 78 is a diagram showing the result of independent component analysis of the vibration shown in FIG. 77. FIG. 79 is a diagram showing a spectrum analysis result of independent components shown by FIG. 78. It is a figure which shows the vibration response when a noise is considered when there is no noise. It is a figure which shows the result of carrying out the spectrum analysis of the vibration response of FIG. It is a figure which shows the result of the analysis which each analyzed the case where it transmits simultaneously with the case where transmission of the vibration response which the sensor of 3 channels measured is transmitted with a delay. It is a figure which shows the result of having spectrum-analyzed the result of FIG. It is a block diagram which shows the internal circuit 30 of the computer of the signal processing apparatus 20 which performs the computer program (signal processing program) of this invention.

Explanation of symbols

  10 bridge, 12 pier, 14a, 14b, 14c sensor, 16 strain sensor, 18 cable, 20 signal processing device, 22 weight, 24, 26 vehicle, 30 internal circuit, 31 CPU, 32 ROM, 33 RAM, 34 display device 35 VRAM, 36 image control unit, 37 controller, 38a disk, 38n CD-ROM, DVD, 39 input control unit, 40 input operation unit, 41 external I / F unit, 42 bus.

Claims (17)

A signal processing method for processing a signal generated by vibration of an object by a signal processing device,
A reception step of receiving a signal generated by vibration of the object by a predetermined sensor group installed at a plurality of predetermined positions of the object and connected to the signal processing device in a predetermined manner;
An extraction step of extracting one or more independent components by processing the plurality of signals received by the receiving step by independent component analysis;
A signal processing method comprising: a natural frequency acquisition step of acquiring a natural frequency of the object by spectrally analyzing one or more independent components extracted in the extraction step.   The signal processing method according to claim 1, further comprising: a diagnosis step of diagnosing strength deterioration of the object based on a comparison between the natural frequency of the object acquired in the natural frequency acquisition step and a predetermined reference value. A signal processing method comprising:   3. The signal processing method according to claim 2, wherein the diagnosis step acquires the natural frequency of the object acquired in the natural frequency acquisition step over a plurality of times, and the maximum of the plurality of natural frequencies is obtained. Alternatively, a signal processing method characterized by diagnosing strength deterioration of the object based on a comparison between a minimum natural frequency and a predetermined reference value.   4. The signal processing method according to claim 1, wherein the object is a pier, and the plurality of predetermined positions are two or more positions between an upper portion and a lower portion of the pier. 5. A characteristic signal processing method.   5. The signal processing method according to claim 1, wherein the predetermined sensor group is an acceleration sensor and / or a speed sensor.   6. The signal processing method according to claim 1, wherein the vibration of the object is caused by any one or more of weight impact, wind force, and vehicle.   7. The signal processing method according to claim 6, wherein when the vibration of the object includes a thing caused by a vehicle, the receiving step is a predetermined position at one or more points around the object or the object, The signal generated by the vibration of the object from the time when a value measured by a strain gauge installed at a position different from the predetermined position of the signal line and connected with the signal processing device in a predetermined manner exceeds a predetermined value. A signal processing method comprising: receiving by a predetermined sensor group installed at a plurality of predetermined positions of an object.   8. The signal processing method according to claim 1, wherein the predetermined method is wireless and / or wired. A signal processing program for processing a signal generated by vibration of an object by a signal processing device, the computer of the signal processing device,
A receiving step of receiving a signal generated by vibration of the object by a predetermined sensor group installed at a plurality of first predetermined positions of the object and connected to the signal processing device in a predetermined manner;
An extraction step of extracting one or more independent components by processing the plurality of signals received in the receiving step by independent component analysis;
A signal processing program for executing a natural frequency acquisition step of acquiring a natural frequency of the object by performing spectrum analysis on one or more independent components extracted in the extraction step.   The signal processing program according to claim 9, further comprising: a diagnosis step of diagnosing strength deterioration of the object based on a comparison between the natural frequency of the object acquired in the natural frequency acquisition step and a predetermined reference value. A signal processing program comprising:   The signal processing program according to claim 10, wherein the diagnosis step acquires the natural frequency of the object acquired in the natural frequency acquisition step over a plurality of times, and the maximum among the plurality of natural frequencies. Alternatively, a signal processing program characterized by diagnosing strength deterioration of the object based on a comparison between the minimum natural frequency and a predetermined reference value.   12. The signal processing program according to claim 9, wherein the object is a pier, and the plurality of predetermined positions are two or more positions between an upper portion and a lower portion of the pier. A characteristic signal processing program.   13. The signal processing program according to claim 9, wherein the predetermined sensor group is an acceleration sensor and / or a speed sensor.   14. The signal processing program according to claim 9, wherein the vibration of the object is caused by any one or more of weight impact, wind force, and vehicle.   15. The signal processing program according to claim 14, wherein when the vibration of the object includes a thing caused by a vehicle, the reception step is the predetermined position at one or more points around the object or the object, The signal generated by the vibration of the object from the time when a value measured by a strain gauge installed at a position different from the predetermined position of the signal line and connected with the signal processing device in a predetermined manner exceeds a predetermined value. A signal processing program that is received by a predetermined sensor group installed at the plurality of predetermined positions of an object.   16. The signal processing program according to claim 9, wherein the predetermined method is wireless and / or wired. A computer-readable recording medium on which the signal processing program according to any one of claims 9 to 16 is recorded.