JP2002071651A - Non-destructive inspection device by collision sound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-destructive inspection device performing an abnormality diagnosis of the interior of a concrete body structure by a rapid inspection speed method based on the collision sound of grains instead of conventional hammer tapping sound. SOLUTION: This non-destructive inspection device is composed of a grain ejecting device 10 ejecting a plurality of grains 11 controlled in the ejection speed and ejection direction, toward a tunnel wall surface 1, an inspected body, and provided with a tray 15 for recovering the grains 11 after colliding with the inspected body; a collision sound recording device 20 comprising a microphone 21 for collecting collision sound when the grains collide with the tunnel wall surface 1, the inspected body, and a recording amplifier device for amplifying and recording the collision sound; and an analysis device 30 comprising an FFT analyzer for making a frequency analysis of the sound recorded in the collision sound recording device 20, and a comparator for comparing data analyzed by the analyzer, with a database for determining abnormal sound and displaying the compared result. The non-destructive inspection device is mounted on a truck 40 with wheels 41 and actuated during travel on a rail 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-destructive inspection device for finding defects and deteriorated portions in a concrete structure represented by a tunnel.

[0002]

2. Description of the Related Art Visual inspection and a hammering sound inspection method using a test hammer are used to diagnose abnormalities in concrete of railway and road tunnels and various structures. However, this is problematic in that the judgment criteria differ depending on the inspector and the inspection speed is slow because of relying on manual labor. On the other hand, as described in JP-A-07-20097, a hammering test using a test hammer is
A method of using a hammer device in which a hammer head is attached to the tip of an air cylinder to make the impact force constant has been studied. However, in this method, although the determination criteria are quantified, the inspection speed is hardly improved.

In the inspection method using an infrared camera developed recently, the criterion is quantified, but it is effective only when a defect appears on the surface, and the inspection speed is said to be faster. In particular, the maximum speed is about 2 km / hr, and especially in the inspection of traffic facility concrete structures such as tunnels and bridges, a method with a higher inspection speed is desired.

[0004]

An inspection apparatus for diagnosing abnormality of a concrete structure is required to have high accuracy and quick inspection speed. Especially for traffic facilities such as railway tunnels or road bridges, non-destructive inspections are required to complete inspections during non-operation at night or when traffic is temporarily interrupted,
In addition, the inspection speed is required to be high.

[0005] The present invention has been made in view of the above problems, and is a non-destructive method for diagnosing abnormalities inside a concrete structure by a method capable of obtaining a quick inspection speed by the impact sound of particles instead of the conventional hammering sound. It is intended to provide an inspection device.

[0006]

In order to achieve the above-mentioned object, a nondestructive inspection apparatus according to the present invention comprises a particle emission device for emitting particles whose emission speed and emission direction are controlled toward an object to be inspected. A recording device that records a collision sound generated when the particles collide with an object to be inspected, an analyzer that performs frequency analysis of the sound recorded in the recording device, and determines data analyzed by the analyzer and abnormal sound. It is characterized by comprising a comparator for displaying the data in comparison with the database.

[0007] In the above nondestructive inspection apparatus, the particle emission device includes a collection device that collects particles that collide with and reflect on the object to be inspected.

[0008] The above-mentioned particle discharge device is characterized in that particles which are solid when discharged, but liquefy or vaporize at atmospheric temperature and atmospheric pressure are used.

Further, the non-destructive inspection device is mounted on a truck having wheels.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view of a case where the present invention is applied to an internal abnormality diagnosis of a concrete structure of a railway tunnel. In the figure, reference numeral 40 denotes a bogie having wheels 41, which can travel on a rail 50 in a tunnel. On the carriage 40, a particle emission device 10, a collision sound recording device 20, and an analysis device 30 are mounted.

The above-mentioned particle emitting device 10 uses a particle accelerator (not shown) to form metallic spherical particles 11 through a plurality of particle emitting holes 12 arranged so as to correspond to the tunnel wall surface 1. 11 are sequentially released in a predetermined speed and direction. The speed of the particles 11 is adjusted so that the momentum of the particles, that is, the mass of the particles × the speed of the particles is substantially the same as the hammer mass × the hammer hitting speed in a conventional hammering sound inspection. Further, the plurality of particles 11 emitted from the plurality of emission holes are arranged such that the collision point 2 with the inner wall of the tunnel scans the tunnel wall 1 at a predetermined circumferential pitch from the lower side of one side, the upper side, the ceiling surface, It is sequentially released in the upper and lower directions on the other side. By repeating this while the carriage 40 is running, collision points 2 with the particles are generated on the tunnel wall 1 at appropriate pitches in the rail direction and the circumferential direction as shown in FIG. Will be emitted.

Further, the particle discharging device 10 includes a receiving tray 15 of a collecting device for receiving the emitted particles 11 colliding with the tunnel wall surface 1 which is the surface to be inspected, and reflecting and falling. A collecting device (not shown) having a supply device for supplying the particles 11 collected to the particle accelerator to the particle accelerator (not shown). The width of the tray 15 is substantially equal to the width of the tunnel, and almost all of the emitted particles 11 are collected. In addition, the surface of the receiving tray 15 is covered with a cushioning material, so that an impact sound generated when receiving the particles 11 is reduced, so that a large disturbance is not made in the judgment of the abnormality diagnosis.

As described above, the collision sound generated one after another by the collision of the particles 11 emitted from the particle emission device 10 with the tunnel wall 1 is recorded and analyzed by the collision sound recording device 20 and the analysis device 30, Diagnose abnormalities.

FIG. 2 is a flow chart for recording and analyzing the collision sound of particles. In the figure, a collision sound is collected and recorded by a collision sound recording device 20 including a microphone 21 and an amplification / recording device 22. The collision sound was located at approximately the same distance from the tunnel wall 1 of the test object.
The sound is collected by a plurality of microphones 21 and amplified and recorded by a collision sound recording device 22.

The collision sound is recorded in the amplifying / recording device 22 and, at the same time, is sent intermittently to the next analyzing device 30 comprising an FFT analyzer 31 and a comparator. The impact sound is FFT
The frequency is analyzed by the high-speed arithmetic processing by the analyzer 31, and the data is sent to the comparator 32 and compared with the database 33 for judging the abnormal sound. The presence or absence of the defect and the deterioration are displayed and recorded together with the location of the collision sound. Generally, if there is an abnormality such as an internal defect, the sound pressure will decrease,
The ratio of low frequency components increases. In the database 33, the threshold value is determined in advance from sound pressure and frequency analysis data of sound of collision of the test object including the running sound of the carriage 40 and the impact sound to the particle collecting device. Can be determined.

As described above, according to the present invention, the carriage 40
While traveling, the collision sound can be analyzed in real time at an appropriate pitch of the inner wall to determine an abnormality. Since the emission time interval of the particles 11 can be made smaller than the frequency analysis time of one collision sound, the inspection pitch is about 0.2 seconds which is a time interval equal to the sum of the collision sound sampling time and the frequency analysis time. 5 km / hr
The above inspection speed becomes possible. Therefore, it is most suitable for an abnormality diagnosis inspection of a concrete structure of a traffic facility requiring a high inspection speed.

In the particle emission device 10 according to the above embodiment, the particles 11 emitted from the plurality of particle emission holes 12
Can be adjusted almost simultaneously to reach the tunnel wall surface 1, which is the surface of the test object. This allows
The inspection speed is slightly faster than in the above embodiment, and collision sounds at a plurality of collision points on one cross section of the tunnel are almost simultaneously concentrated, and the particles 11 are reflected from the surface of the inspection object and collected. Since the noise generated when received by the device is delayed, the noise is hardly affected by the abnormality diagnosis, and is applied to an object requiring more accurate diagnosis. However, if there is an abnormality,
In order to specify the locations, it is necessary to sequentially emit in the circumferential direction and perform the determination again one by one.

The particles 11 used in the particle discharge device 10 in the above embodiment are solid at the time of being discharged from the discharge holes, such as ice particles or dry ice, and after colliding with the object to be inspected, It is also possible that the substance liquefies or vaporizes at room temperature and atmospheric pressure and has no toxicity.
As a result, the emitted particles 11 can be disposable, so that the collecting device attached to the particle emitting device 10 becomes unnecessary, and the device becomes simpler. However, in the case of ice, since the specific gravity is smaller than that of metal, it is necessary to increase the release speed in order to make the momentum of the particles, that is, the mass of the particles × the release speed of the particles approximately equal to the momentum of the hammer. .

In the particle emission device 10 of the above embodiment, the number of the particle emission holes 12 is one, and the emission direction of the particles 11 is scanned by approximately 180 degrees so as to follow the shape of the inner wall of the tunnel as a non-inspection object. Is also possible. Thereby, it is possible to apply to the inspection of the bolt fastening state at the time of the inspection of the vehicle where the inspection region is relatively local.

In the particle emitting device 10 in the above embodiment, in the case of metal particles, the collecting device can collect the particles scattered after the collision by magnetism without providing the receiving tray. The present invention can be applied to the case of the shape of the inspection object in which the particles do not scatter over a wide range after the collision with the inspection object.

[0021]

The non-destructive inspection device using the collision sound of particles according to the present invention emits particles while running a truck,
It is possible to cause the test object to collide at an appropriate pitch, analyze the collision sound in real time, and determine the presence or absence of abnormality almost continuously. Thus, a nondestructive inspection device with a high inspection speed can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing an embodiment in which the present invention is applied to abnormality diagnosis of concrete in a railway tunnel.

FIG. 2 is a flowchart of recording and analysis of a collision sound of particles.

FIG. 3 is a perspective view showing a trajectory of a collision point of particles on a tunnel wall surface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tunnel wall 2 Collision point 10 Particle emission device 11 Particle 12 Particle emission hole 15 Receiving tray 20 Collision sound recording device 21 Microphone 22 Amplification / recording device 30 Analysis device 31 FFT analyzer 32 Comparator 33 Database 40 Dolly 50 Rail

Claims (4)

[Claims] 1. A particle emission device that emits a plurality of particles whose emission speed and emission direction are controlled toward a test object, and a recording device that records a collision sound generated when the particles collide with the test object. And an analyzer for frequency-analyzing the sound recorded in the recording device, and a comparator for comparing and displaying data analyzed by the analyzer with a database for judging abnormal sound, and a collision sound. Non-destructive inspection equipment. 2. The nondestructive inspection device according to claim 1, wherein the particle emission device includes a collection device that collects particles that collide with and reflect on the object to be inspected. 3. The particle discharging device according to claim 1, wherein particles which are solid when discharged, but liquefy or vaporize at atmospheric temperature and atmospheric pressure are used.
A nondestructive inspection device using a collision sound according to any one of the above. 4. The nondestructive inspection device according to claim 1, wherein the nondestructive inspection device is mounted on a bogie having wheels.