JP6948241B2 - Evaluation method of incidental support status - Google Patents

Description

The present invention relates to a method for evaluating an accessory supporting state, which is performed by measuring the vibration of an accessory attached to the surface of a structure from a distant position with a non-contact vibration measuring device.

As disclosed in Patent Documents 1 and 2, there is known a method of diagnosing the soundness of a concrete structure made of reinforced concrete, such as whether or not cracks have occurred.

Patent Documents 1 and 2 disclose a method of diagnosing soundness by measuring the natural frequency of a concrete structure. That is, if the natural frequency when the concrete structure is in a healthy state is measured and the natural frequency measured at the time of inspection is lower than the natural frequency when the concrete structure is in a healthy state, the concrete structure is cracked. It is possible to diagnose that there is damage or deterioration such as occurrence.

Japanese Unexamined Patent Publication No. 2011-247700 Japanese Unexamined Patent Publication No. 2005-233709

When the main body of a concrete structure as described in Patent Documents 1 and 2 is targeted, the soundness can be estimated relatively easily from the degree of change in the natural frequency. However, when it comes to ancillary materials such as an outer wall material attached to the surface of a structure, it becomes difficult to judge the soundness. For example, in the case of an outer wall material fixed to the main body of a structure with a large number of screws, even if several screws are loosened, they will not fall, but if more than a certain number of screws are loosened, there is a risk of sudden falling. It is difficult to evaluate the support status on a uniform basis, as it may increase.

Therefore, the present invention provides a method for evaluating an accessory support state, which can evaluate a plurality of support states of an accessory attached to the surface of a structure with high accuracy by measuring vibration remotely. The purpose is.

In order to achieve the above object, the method for evaluating the supporting state of ancillary objects of the present invention is performed by measuring the vibration of the ancillary objects attached to the surface of the structure from a distant position by a non-contact vibration measuring device. This is a method for evaluating an object support state, and obtains a judgment standard showing the relationship between a plurality of support states of the accessory to the main body of the structure and a discrimination value obtained from the measurement result by the non-contact vibration measuring device. Steps to measure vibration with the non-contact vibration measuring device when the accessory to be measured is vibrating, and a step to obtain a discriminant value of the measurement target from the measurement result by the non-contact vibration measuring device. It is characterized by including a step of determining the support state of the accessory from the determination value of the measurement target and the determination criterion.

Here, the discriminant value can be a natural frequency or a dominant frequency. Further, a laser Doppler vibrometer can be used for the non-contact vibration measuring device.

Further, the vibration of the accessory to be measured may be due to constant fine movement. On the other hand, it is preferable that the determination standard is created for each of the structures by vibrating a plurality of supporting objects of the structure with a vibrating device.

The method for evaluating the supporting state of ancillary objects according to the present invention configured in this way is a method of evaluating a plurality of supporting states of ancillary objects attached to the surface of a structure and a discriminant value obtained from a measurement result by a non-contact vibration measuring device. Obtain the judgment criteria showing the relationship in advance. Then, the support state of the accessory is determined based on the result measured by the non-contact vibration measuring device and the determination standard when the accessory to be measured is vibrating.

Therefore, if the accessory attached to the surface of the structure vibrates due to constant fine movement or forced vibration, it is possible to remotely evaluate with high accuracy which state the support state is. ..

The natural frequency and the dominant frequency can be used as the discriminant value obtained from the measurement result by such a non-contact vibration measuring device. Further, a laser Doppler vibrometer can be used as the non-contact vibration measuring device.

If the judgment criteria are created in advance, the vibration of the accessory to be measured may be generated by constant fine movement, so even if the accessory is in a high place, a periodic inspection or the like can be easily performed. be able to.

On the other hand, the judgment standard can be created for each structure by vibrating a plurality of supporting objects with a vibrating device. By creating a judgment standard for each structure, more accurate evaluation can be performed.

It is a perspective view explaining the measurement situation by the laser Doppler vibrometer carried out by the evaluation method of the accessory support state of this embodiment. It is a flowchart explaining the process performed at the first time in order to carry out the evaluation method of the incidental support state. It is explanatory drawing which shows the plurality of support states of the outer wall material, and explains the deterioration scenario. It is explanatory drawing which illustrated the judgment standard used when the support state is judged by the relationship between a natural frequency and an effective number of screws. It is a flowchart explaining the process performed at the time of a periodic inspection in order to carry out the evaluation method of the incidental support state.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view illustrating a vibration measurement state carried out by the method for evaluating an accessory support state of the present embodiment.

The structure to which the method for evaluating the supporting state of ancillary objects of the present embodiment is applied is, for example, a building M to which an outer wall material M1 (incidental object) such as a tile or a panel is attached to the surface. Here, the outer wall material M1 is attached to the surface of the main body of the building M by a screw M2, an adhesive, or the like.

In the method for evaluating the supporting state of the accessory according to the present embodiment, the supporting state of the outer wall material M1 is determined by measuring the vibration generated in the outer wall material M1. Here, the supporting state of the outer wall material M1 refers to, for example, the degree of joint strength with the main body of the building M.

For example, as shown in FIG. 3, a case where the outer wall material M1 is fixed to the main body of the building M by a plurality of screws M2, ... Will be described as an example. FIG. 3A shows a sound state (initial state) in which the outer edge portion is fixed by all 18 screws M2, ...

When the bonding by the screws M2, ... Is gradually lowered, for example, in the state of being fixed by the nine screws M2, ... As shown in FIG. 3 (b), FIG. 3 (c) is obtained. The state of being fixed by the four screws M2, ... As shown, and the state of being fixed by the two screws M2, M2 as shown in FIGS. 3 (d) and 3 (e) are changed. Become. These different joining states are referred to as "plurality of supporting states".

If the supporting state of the outer wall material M1 is different, the natural frequency when the outer wall material M1 vibrates also has a different value. However, the natural frequency does not always directly indicate the support state of the outer wall material M1. For example, in the case of a continuous body such as a concrete body, it is easy to estimate the rigidity directly from the natural frequency, but in the case of the outer wall material M1 in a state where a plurality of joint points are scattered and suspended, the surface is used. It may be difficult to directly estimate the support state from the measurement result of the vibration generated in the concrete.

Therefore, in the method of evaluating the incidental support state of the present embodiment, a determination criterion for determining which of the "plurality of support states" corresponds to the support state is created. This determination criterion is preferably created for each building M to be measured, but it is also possible to use a criterion made of another structure having the same or similar material and supporting state of the outer wall material M1.

The judgment standard is created by summarizing the relationship between a plurality of support states of the outer wall material M1 as an accessory to the main body of the building M and a judgment value obtained from the measurement result of the vibration of the outer wall material M1.

Here, the vibration of the outer wall material M1 is measured by a non-contact vibration measuring device. As the non-contact vibration measuring device, a laser Doppler vibrometer 1 as shown in FIG. 1 can be used.

The laser Doppler vibrometer 1 is mainly composed of a main body including an irradiation unit 11, a vertical rotating frame portion 14 and a horizontal rotating table 13 to which the main body is attached, and a tripod portion 12 for installing the laser Doppler vibrometer 1. ..

The laser Doppler vibrometer 1 is a device that irradiates the outer wall material M1 attached to the surface of the building M with the laser light D1 from the sensor head of the irradiation unit 11 and receives the reflected laser light D1 with the light receiving element. If the outer wall material M1 vibrates due to forced vibration or constant tremor, which will be described later, the laser light D1 reflected from the vibrating outer wall material M1 is Doppler-shifted laser light D1, and the change in frequency (velocity) is a voltage. It can be converted to and detected as a vibration phenomenon.

The irradiation unit 11 of the laser Doppler vibrometer 1 is attached to the horizontal rotary table 13 via the vertical rotary frame portion 14 so as to be able to rotate in a horizontal plane. The vertical rotary frame portion 14 is formed in a pair of columns on the horizontal rotary table 13, and the irradiation portion 11 is rotatably attached to the vertical rotary frame portion 14 in a vertical plane.

Here, the horizontal turntable 13 and the vertical rotary frame portion 14 can be operated to manually aim the irradiation unit 11 at the target, but the motor and gear are incorporated inside the horizontal turntable 13 and the vertical rotary frame portion 14. , It is also possible to automatically rotate horizontally and vertically in a specified direction in response to a control signal.

Further, the laser Doppler vibrometer 1 can be configured to include a surveying device such as a range finder 15. A laser range finder or the like can be used for the range finder 15. By irradiating the position P2 adjacent to the irradiation position P1 of the laser light D1 of the laser Doppler vibrometer 1 with the laser light D2 of the rangefinder 15, the distance to the vibration measurement point can be quickly measured. That is, by using the relative positional relationship between the irradiation positions P1 and P2, it is possible to obtain the coordinates of the vibration measurement point (irradiation position P1).

Further, as the laser Doppler vibrometer 1, a laser Doppler vibrometer 1 having a built-in inclination sensor or vibration sensor can be used so that noise due to wind or ground vibration can be corrected in real time.

On the other hand, a reflective material can be attached in advance to the irradiation position P1 of the laser beam D1 of the laser Doppler vibrometer 1. Further, by firing and adhering a paint bullet in which the retroreflective paint is enclosed, a portion where a highly reflective reflective surface is secured can be set as the irradiation position P1. Further, it is also possible to find a position suitable for the measurement in which the reflectance is high from the measurement target range of the outer wall material M1 and set it as the irradiation position P1.

From the measurement result of the vibration (micro vibration) measured by the laser Doppler vibrometer 1 at a remote position away from the outer wall material M1 in this way, a discriminant value for specifying the support state of the outer wall material M1 is obtained.

As this discriminant value, the natural frequency or the predominant frequency corresponding thereto can be used. For example, as shown in FIG. 1, when a small exciter 2 is installed on the surface of the building M and forcibly vibrated, the outer wall material M1 having the irradiation position P1 can also be vibrated by the propagated vibration. .. When the measurement result obtained by applying the forced vibration in this way is used, the dominant frequency such as the peak frequency can be used as the estimated value of the natural frequency.

On the other hand, the outer wall material M1 may also be vibrated by constant fine movements such as vibrations generated by a vehicle passing through a road adjacent to the building M and vibrations caused by wind. The natural frequency can also be obtained by measuring such vibrations and minute vibrations due to constant fine movements with the laser Doppler vibrometer 1.

In short, it is a method of specifying the natural frequency based on the Fourier spectrum obtained from the measurement result of vibration due to constant tremor. For example, the frequency in which the search range of the frequency is set and the amplitude of the Fourier spectrum is maximized can be regarded as the natural frequency.

Next, the method of evaluating the incidental support state of the present embodiment will be described with reference to the flowcharts of FIGS. 2 and 5. Here, the flowchart shown in FIG. 2 shows the processing performed for the first time for the building M to be measured, and the flowchart shown in FIG. 5 is for periodically inspecting the building M to be measured. Indicates processing.

First, as shown in step S1 of FIG. 2, a deterioration scenario suitable for a material such as a porcelain tile or a metal panel of the outer wall material M1 of the building M and a support form is set. For example, as shown in FIG. 3A, a deterioration scenario of the outer wall material M1 fixed to the main body of the building M by a total of 18 screws M2, ... So as to surround the edge of the rectangular metal panel. To create.

In such an outer wall material M1, it is assumed that the support state may change because the screw M2 gradually loosens or the fixing portion of the screw M2 becomes brittle and the joint strength cannot be locally secured. Such a change in the supporting state will be expressed as a change in the number of effective screws. That is, FIG. 3 (a) shows the number of effective screws of 18, FIG. 3 (b) shows the number of effective screws of 9, FIG. 3 (c) shows the number of effective screws of 4, and FIG. 3 (d) shows the number of effective screws. 3 shows five support states only on the upper side, and FIG. 3 (e) shows two effective screws only on the lower side.

Therefore, in each of these five support states, the natural frequency obtained from the measurement result of the vibration of the outer wall material M1 is obtained. The calculation of the natural frequency can be obtained by numerical analysis as shown in step S21, but here, a case where it is obtained by a forced vibration test will be described (step S2).

In the forced vibration test, as shown in FIG. 1, for example, a small vibrator 2 is applied to the surface of the building M to apply vibration. The position of the vibrating device 2 may be separated from the outer wall material M1 to be measured, and the vibration may be propagated. In short, since it is sufficient that the outer wall material M1 generates minute vibrations, the exciter 2 can be applied to a place where the inspector can easily contact the outer wall material M1.

Here, as the outer wall material M1 to be subjected to the forced vibration test, the one having the above-mentioned five support states is selected. If there is a support state that does not currently exist among the five support states, it may be provided for testing.

In the forced vibration test, a laser Doppler vibrometer 1 is installed on the ground adjacent to the building M, and the outer wall material M1 is vibrated by the vibrometer 2 to collect vibration measurement results. Then, the natural frequency is calculated based on the recorded measurement result.

FIG. 4 shows a diagram in which the five support states are represented by the number of effective screws on the vertical axis and the corresponding natural frequency is on the horizontal axis. This figure is a diagram showing a criterion for determining the support state of the outer wall material M1. For example, when the number of effective screws is 18, it indicates a sound state, so the region I where the natural frequency is 60 Hz or more is set as a region to be judged as sound.

On the other hand, the region II in which the number of effective screws is 4 to 18 and the natural frequency is 35 Hz-60 Hz is defined as a region in which deterioration is judged to be progressing. Further, the region III in which the number of effective screws is 2 to 4 and the natural frequency is 20 Hz-35 Hz is defined as a region where caution is required (need attention). The region IV having an effective screw number of 2 or less and a natural frequency of 20 Hz or less is a region where it is determined that there is a risk of the outer wall material M1 falling.

After creating the determination criteria in step S3 in this way, a forced vibration test for grasping the current state of all the outer wall materials M1, ... Currently attached to the building M is performed (step S4).

This forced vibration test can be performed simply by moving only the irradiation position of the laser beam D1 by the irradiation unit 11 of the laser Doppler vibrometer 1 without changing the installation location of the vibrator 2. Can be done.

Then, the natural frequencies of the respective outer wall materials M1, ... Are calculated, the current support state is confirmed by the above-mentioned determination criteria, and they are saved as a database (step S5). At this time, the exact coordinates of the outer wall material M1 are not always necessary, and for example, the calculated natural frequency data may be stored in association with the code of each outer wall material M1 attached to the side view of the building M. .. In addition, if the judgment below caution (Area III) is made at this point, repair it to a sound support state by measures.

The periodic inspection shown in FIG. 5 is performed at intervals set according to the usage status of the building M and the like. At the time of this periodic inspection, the forced vibration test using the exciter 2 described above can be performed, but the inspection can also be performed by the vibration generated in the outer wall material M1 due to the constant fine movement (step S11).

Since the inspection by constant fine movement can be performed only by installing the laser Doppler vibrometer 1, it is possible to carry out the inspection more frequently than the normal periodic inspection or as a daily inspection. Then, in step S12, the natural frequencies of all the outer wall materials M1, ... Are calculated from the measurement results.

In step S13, the calculated natural frequency is collated with the determination criteria shown in FIG. 4 to determine whether or not detailed inspection is necessary. For example, when it is determined to be region I or region II, it is determined that it is not necessary to take immediate measures, and only the database of natural frequencies is updated (step S14). This makes it possible to record the support state of the outer wall material M1 at the time of periodic inspection. In short, it is possible to record the change over time in the support state of the outer wall material M1.

On the other hand, if it is determined to be region III or region IV, the process proceeds to the detailed inspection in step S15. The detailed inspection is a forced vibration test or an inspection performed by directly contacting the outer wall material M1 with a scaffolding.

It is determined by a detailed inspection whether or not it is necessary to take measures, and if it is determined that no measures are necessary, the process proceeds to step S14 and only the database is updated. If it is determined that measures are necessary for this, measures are taken to repair the support state to a sound state (step S16).

Next, the operation of the method for evaluating the incidental support state of the present embodiment will be described.
The method of evaluating the incidental support state of the present embodiment configured in this way is obtained from the plurality of support states of the outer wall material M1 previously attached to the surface of the building M and the measurement result by the laser Doppler vibrometer 1. Obtain a criterion that shows the relationship with the natural frequency. Then, the support state of the outer wall material M1 is determined based on the result measured by the laser Doppler vibrometer 1 and the determination standard when the outer wall material M1 to be measured is vibrating.

Therefore, if the outer wall material M1 attached to the surface of the building M is constantly vibrating due to tremor or forced vibration, it can be measured with high accuracy to determine which state the support state is. Can be evaluated.

If the determination criteria are created in advance, the vibration of the outer wall material M1 to be measured may be generated by constant fine movement, so that it is necessary to assemble a scaffolding or the like even when the outer wall material M1 is in a high place. It is possible to easily carry out regular inspections.

On the other hand, the determination standard can be created for each building M by vibrating a plurality of supported outer wall materials M1 by the exciter 2. By creating a determination standard for each building M, it becomes possible to perform more accurate evaluation suitable for the material and support form of the outer wall material M1 attached to the building M.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes to the extent that the gist of the present invention is not deviated are described in the present invention. Included in the invention.

For example, in the above-described embodiment, the outer wall material M1 of the building M has been described as an example, but the present invention is not limited to this, and even when an accessory such as a panel is attached to the side surface of the retaining wall or the pier. The present invention can be applied.

Further, in the above-described embodiment, the case where the laser Doppler vibrometer 1 is used as a non-contact vibration measuring device has been described, but the present invention is not limited to this, and vibration generated on the surface of an accessory can be measured remotely. It may be a device.

1 Laser Doppler vibrometer (non-contact vibration measuring device)
2 Exciter M Building (Structure)
M1 outer wall material (incidental)

Claims (5)

It is a method of evaluating the supporting state of ancillary objects, which is performed by measuring the vibration of ancillary objects attached to the surface of a structure from a distant position with a non-contact vibration measuring device.
From the relationship between three or more types of support states of the accessory to the main body of the structure prepared based on the set deterioration scenario and the discriminant value obtained from the measurement result by the non-contact vibration measuring device, three or more. And the step of acquiring the judgment criteria having the judgment area of
The step of measuring the vibration by the non-contact vibration measuring device when the accessory to be measured is vibrating,
The step of obtaining the discriminant value of the measurement target from the measurement result by the non-contact vibration measuring device, and
A method for evaluating an accessory support state, which comprises a step of determining which of the determination areas the support state of the accessory belongs to from the determination value of the measurement target and the determination criterion. The method for evaluating an accessory supporting state according to claim 1, wherein the discriminant value is a natural frequency or a dominant frequency. The method for evaluating an accessory support state according to claim 1 or 2, wherein the non-contact vibration measuring device is a laser Doppler vibrometer. The method for evaluating an accessory support state according to any one of claims 1 to 3, wherein the vibration of the accessory to be measured is always due to fine movement. The determination standard is described in any one of claims 1 to 4, wherein the determination criteria are created for each of the structures by vibrating a plurality of supporting objects of the structure with a vibrating device. How to evaluate the support status of incidental objects.

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