JP6533458B2 - Foreign matter inspection system for a concrete structure, foreign matter inspection apparatus and foreign matter inspection method - Google Patents

Description

  The present invention relates to a foreign matter inspection system for a concrete structure, a foreign matter inspection device, and a foreign matter inspection method, and in particular, a nondestructive inspection technique for inspecting foreign matter inside the concrete structure (including flaws, junk, etc.) using ultrasonic waves. About.

  Conventionally, as one nondestructive inspection of foreign matter (scratch, junka, etc.) inherent in a concrete structure, a pair of ultrasonic probes are disposed on the surface of the concrete structure, and one of the probes is used to make concrete There is known a method called ultrasonic flaw inspection which performs flaw detection by propagating ultrasonic waves to a structure and receiving a reflected wave from a foreign matter inherent in a concrete structure with the other probe. In this inspection, it is known that the resolution of ultrasonic waves is improved as the wavelength is shorter.

  In general, ultrasonic waves are longitudinal waves (compressed waves) that propagate using density change, so if they are vertically incident on a concrete structure in the above ultrasonic flaw inspection, foreign matter is present in the concrete structure. In the case where there is a void, there is a problem that the light is easily reflected on the top face of the pore and thus is not attenuated and reaches the bottom, so that it is difficult to obtain a reflected wave on the bottom. If a reflected wave at the bottom of the pore can not be obtained, foreign matter in the concrete structure can not be detected sufficiently, which is not desirable. This problem is more pronounced as the wavelength is shorter.

  On the other hand, it is known that transverse waves (shear waves) generally have the property of being less susceptible to the influence of pores. Therefore, for example, it is considered to propagate a transverse wave (shear wave) rather than a longitudinal wave (compression wave) inside the concrete structure by causing an ultrasonic wave to be incident on the concrete structure at an oblique angle.

  Also, recently, low-frequency (for example, 10 to 300 Hz) sound waves that are generated toward the seabed in seawater are converted to transverse waves at the seabed, and transverse waves are favorably propagated to the ground regardless of the state of the seabed. A seabed resource exploration technique is known that enables stable exploration of seabed resources buried in the inside (Patent Document 1).

JP, 2014-137320, A

  In ultrasonic flaw detection using the above-mentioned shear wave (shear wave), an ultrasonic probe is installed on the surface of a concrete structure, and an ultrasonic wave is made to be incident at an oblique angle so as to generate a shear wave inside the concrete structure. In this case, if there are irregularities on the surface of the concrete structure, the refraction angle will not be stable and the incident intensity of the ultrasonic wave will decrease, and it will be difficult to propagate the transverse wave perpendicular to the surface of the concrete structure. There is. If the transverse wave can not be propagated perpendicularly to the surface of the concrete structure in this manner, the reflected wave can not be stably received, which is not desirable.

  Further, the technology disclosed in the above-mentioned Patent Document 1 is a technology for generating a sound wave of low frequency (for example, 10 to 300 Hz) in the sea (in water) to search the submarine resource, and the target to be searched is also the submarine resource It is very different from the foreign matter inherent in the concrete structure.

  The present invention has been made to solve such a problem, and a foreign matter inspection system for a concrete structure, a foreign matter inspection device, and a concrete structure inspection system capable of reliably inspecting foreign matter inside a concrete structure using a shear wave. It aims at providing a foreign substance inspection method.

  In order to achieve the above object, the foreign matter inspection system for a concrete structure according to the present invention is provided with a liquid for immersing a part or the whole of the surface of the concrete structure, and each vibrator is provided to be immersed in the liquid. A plurality of ultrasonic probes for causing an ultrasonic wave consisting of compressional waves to oscillate from each of the vibrators toward a structure, and a receiving unit are provided so as to be immersed in the liquid, and a sound receiver for receiving the reflected waves of the ultrasonic waves A controller for controlling the phase of the ultrasonic waves respectively generated from the plurality of ultrasonic probes, and analysis of received information from the receiver to analyze foreign particles in the concrete structure A plurality of ultrasonic probes such that a shear wave is generated on the surface of the concrete structure and the shear wave propagates inside the concrete structure. Apply a phase difference between the ultrasonic waves, each of which is vibrated, and the geophones are reflected inside the concrete structure and converted from shear waves to compression waves on the surface of the concrete structure to be introduced into the liquid Receive an ultrasonic wave propagating through as a reflected wave.

Preferably, the control device applies a half cycle phase difference between the ultrasonic waves generated by the plurality of ultrasonic probes.
Preferably, the plurality of ultrasonic probes are configured such that the plurality of ultrasonic waves generated by the plurality of ultrasonic probes overlap each other on the surface of the concrete structure. The distance between each of the transducers and the distance from each of the transducers to the surface of the concrete structure may be set.
Preferably, the plurality of ultrasound probes are a pair of ultrasound probes.

  The foreign substance inspection apparatus for a concrete structure according to the present invention is a frame-like liquid tank portion which is placed on the surface of the concrete structure and holds the liquid on the surface, and each vibrator is the concrete structure. A pair of seismic transducers for vibration application, which are provided in parallel so as to be immersed in the liquid accumulated in the liquid tank part facing the surface, and generate ultrasonic waves from the respective transducers toward the concrete structure; Part is provided so as to be immersed in the liquid, and the ultrasonic transducer for vibration reception receives the reflected wave of the ultrasonic wave, the pair of ultrasonic transducers for vibration application and the ultrasonic transducer for vibration reception as the concrete A support member movably supported along the surface of the structure, a control unit for controlling the phases of the ultrasonic waves respectively generated from the pair of seismic ultrasonic probes, and the ultrasonic transducer for seismic reception Analyze the information received from the The foreign bodies within preparative structure and a recognizing analyzer.

Preferably, the receiving ultrasonic probe has one receiving portion and is supported by the support member so as to be movable independently of the pair of seismic ultrasonic probes. Good.
Preferably, the liquid tank portion is configured to have a bottom portion in close contact with the surface of the concrete structure.

  Further, in the foreign matter inspection method for a concrete structure according to the present invention, a control step of controlling the phase of ultrasonic waves respectively generated from a plurality of ultrasonic probes, and each transducer is one of the surfaces of the concrete structure. From each of the transducers of the plurality of ultrasound probes arranged to be immersed in the liquid to be immersed in part or the whole, and emitting an ultrasonic wave consisting of the phase controlled compression wave toward the concrete structure A vibration receiving process, a vibration receiving process for receiving the reflected wave of the ultrasonic wave by a vibration receiving device provided so as to be immersed in the liquid, and a vibration receiving information from the vibration receiving device to analyze foreign matter inside the concrete structure And, in the control step, a shear wave is generated on the surface of the concrete structure so that the shear wave propagates inside the concrete structure, between the ultrasonic waves. In the receiving step, an ultrasonic wave which is reflected inside the concrete structure and converted from a shear wave to a compression wave on the surface of the concrete structure is received as a reflected wave as a reflected wave. .

  According to the foreign matter inspection system for a concrete structure, the foreign matter inspection apparatus, and the foreign matter inspection method of the present invention, the shear wave is propagated inside the concrete structure to confirm also the lower surface of the foreign matter which was difficult to inspect in the compression wave. It is possible to well recognize the position and size of the foreign matter present inside the concrete structure.

  In particular, ultrasonic waves consisting of compressional waves having a phase difference are emitted from the respective transducers of a plurality of ultrasonic probes in the liquid that dips the surface of the concrete structure to the concrete structure, and the surface of the concrete structure Since the shear wave is generated in the above, the surface of the concrete structure is taken into consideration without considering the angle of refraction of the ultrasonic wave itself which has been considered to be a problem in the prior art, ie without being affected by the surface irregularities of the concrete structure. The shear wave perpendicular to the surface of the concrete structure can be reliably transmitted to the inside of the concrete structure, the stable reflected wave without dispersion can be received by the geophone, and the position and size of the foreign matter existing inside the concrete structure can be It can be recognized accurately.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the foreign material inspection apparatus as one Embodiment of the foreign material inspection system of the concrete structure which concerns on this invention. It is a figure which shows the distance X which is the center-to-center distance of each vibrator | oscillator of a pair of ultrasonic transducers for earthquake generation, and the distance X from each vibrator | oscillator to a concrete structure. It is a figure which shows the relationship (b) between relative incident angle (theta) (a) and relative incident angle (theta) and the amplitude of a transverse wave to the surface of the concrete structure of each ultrasonic wave emitted from a pair of ultrasonic transducers for earthquake . It is a figure which shows the conversion condition (a) from the longitudinal wave to the transverse wave in the surface of the concrete structure of the ultrasonic wave which accel- erated from a pair of ultrasonic transducers for earthquakes and the detail (b). It is a figure which shows the receiving condition (a) and the detail (b) in the receiving ultrasonic probe of the receiving ultrasonic wave of the reflected wave reflected inside the concrete structure. It is a figure which shows the modification of a foreign material inspection apparatus. It is a figure which shows the implementation condition of the Example using a foreign material inspection apparatus. It is a figure which shows the flow of the test | inspection in an Example. It is a figure which shows the test result in an Example with an image. It is a figure which shows the test result in the comparative example using a longitudinal wave with an image.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an entire configuration diagram of a foreign matter inspection apparatus as an embodiment of a foreign matter inspection system for a concrete structure according to the present invention.

The foreign substance inspection apparatus 10 has a water tank (liquid tank) 20 for storing water (liquid) 28 on the surface of the concrete structure 1 and a top surface 23 of the outer wall 22 of the water tank 20 on the surface of the concrete structure 1. Rail (supporting member) 30 passed along, and a pair of seismic ultrasonic probes (ultrasound probes) that are suspended (supported) by rail 30 in parallel along rail 30 and movable along rail 30 Similarly, an ultrasonic probe (receiver) 50 suspended on the rail 30 and movable along the rail 30 and a control unit 60 are provided.
Concrete structures also include asphalt, mortar and the like.

  The water tank unit 20 is configured, for example, so as to place a frame-like outer wall 22 made of resin on the surface of the concrete structure 1. The lower end periphery of the outer wall 22 is integrally or separately provided with, for example, a soft resin or a soft rubber material so as to be in close contact with the surface of the concrete structure 1. Even if the water is collected, the water stored in the water tank 20 is prevented from leaking to the outside. A sealing material such as an adhesive may be filled between the lower end periphery of the outer wall 22 and the surface of the concrete structure 1 instead of the soft resin or the soft rubber material.

  The bottom area of the water tank portion 20 is determined according to the size and range of the concrete structure 1 to be inspected, and the sizes and ultrasonic waves of the ultrasonic transducers 40 and 42 for vibration generation and the ultrasonic transducers 50 for vibration reception The required water volume is determined according to the characteristics of the above and the installation conditions described later, and the height H (see FIG. 2) of the outer wall 22 is determined. Then, at the time of the foreign substance inspection, the water 28 is accumulated in the water tank portion 20 to the necessary water bulk position.

  The rail 30 is configured to be able to move freely on the upper end 23 of the outer wall 22 of the water tank 20 according to the place where the concrete structure 1 is to be inspected.

  The pair of seismic ultrasonic probes 40 and 42 for generating an ultrasonic wave is a surface of the concrete structure 1 on each lower surface so as to generate an ultrasonic wave toward the surface of the concrete structure 1. And the vibrators 41 and 43 are provided. Here, the frequency of the ultrasonic waves generated from the ultrasonic transducers 40 and 42 for earthquake generation is several tens kHz to several hundreds kHz, and is appropriately set according to the concrete structure 1 to be inspected. Then, in the state in which the distance between the centers of the respective transducers 41 and 43 is previously set to the distance L (see FIG. 2), the vibration ultrasonic probes 40 and 42 are integrated with the rail 30 via the slide bracket 32. It is suspended and configured to be integrally movable along the rail 30 while maintaining the distance L. At the time of the foreign substance inspection, the vibration ultrasonic probes 40 and 42 are in a state in which at least the respective transducers 41 and 43 are immersed in the water 28 stored in the water tank unit 20.

  Referring to FIG. 2, the installation conditions of the seismic transducer 40, 42 for the concrete structure 1, specifically, the above-mentioned distance L and the transducers 41, 43 of the seismic probe 40, 42. The distance X from the concrete structure 1 to the concrete structure 1 and the upper end 23 of the outer wall 22 of the water tank portion 20, that is, the height H to the rail 30 are shown, and the distance L and the distance X which are installation conditions will be described.

  In the foreign matter inspection apparatus 10, superposing a pair of longitudinal waves (compression waves) generated by the transducers 41 and 43 of the ultrasonic transducers 40 and 42 for earthquake generation in water on the surface of the concrete structure 1 The transverse wave (shear wave) perpendicular to the surface of the concrete structure 1 is propagated to the inside of the concrete structure 1. For this reason, as shown in FIG. 2, it is considered as a requirement for defining the above-mentioned installation condition that ultrasonic waves of a pair of longitudinal waves overlap with each other on the surface of the concrete structure 1.

The ultrasonic waves generated from the ultrasonic transducers 40 and 42 for earthquakeing have directivity, and the directivity angle φ is based on the characteristics of the ultrasonic waves, etc. according to the specifications of the probe, and the following equation (1) It is set by.
φ = 70 × λ / D (1)
Here, λ is the wavelength of the ultrasonic wave, and D is the diameter of each of the transducers 41 and 43.

  By the way, the larger the amplitude of the transverse wave (shear wave) generated inside the concrete structure 1, the better the foreign substance inspection.

  Referring to FIG. 3, relative incident angles θ (a) of the ultrasonic waves emitted from the ultrasonic transducers 40 and 42 to the surface of the concrete structure 1 are schematically shown, and the relative incident angles θ and The relationship (b) with the amplitude of the shear wave is shown as the measured value.

  As shown in FIG. 3 (b), the amplitude of the transverse wave depends on the relative incident angle θ at the surface of the concrete structure 1 between the ultrasonic waves of a pair of longitudinal waves oscillated from the ultrasonic transducers 40 and 42 for earthquake As the relative incident angle .theta. Approaches 90.degree., The amplitude of the transverse wave increases and a good foreign substance inspection is possible.

  In the case of emitting ultrasonic waves of the same characteristic from the seismic transducer 40, 42, half θ / 2 of the relative incident angle θ is a pointing angle φ. Therefore, preferably, it is desirable that the directivity angle φ of the ultrasonic waves generated from the vibration ultrasonic probes 40 and 42 be close to 45 °, which is θ / 2.

Then, in order to superimpose a pair of longitudinal waves of ultrasonic waves on the surface of the concrete structure 1, as shown in FIG. 2, the directivity of ultrasonic waves emitted from the ultrasonic transducers 40 and 42 for earthquake is shown. The ultrasonic waves need to overlap each other within the directivity range with the directivity angle φ on the surface of the concrete structure 1, and in order to satisfy this requirement, the distance L and the distance X based on the following equation (2) Is set appropriately.
2 ××× tan (70 × λ / D)> L−D (2)

  In fact, since each case has a constant width dimension in each of the vibration ultrasonic probes 40 and 42, the distance L corresponds to each case of the respective vibration ultrasonic probes 40 and 42. The minimum value is determined according to the width dimension of the body, and is set to the minimum value or more. Then, the distance X is set based on the value of the distance L.

  As described above, the closer the relative incident angle θ to the surface of the concrete structure 1 of each ultrasonic wave emitted from the ultrasonic transducers 40 and 42 for earthquake is closer to 90 °, ie, the ultrasonic probe for earthquake As the directivity angle φ of the ultrasonic waves generated from the child 40 and 42 is closer to 45 °, a better foreign substance inspection is possible. In practice, the directivity angle φ is often less than 45 °, and in the case where the directivity angle φ is less than 45 °, the ultrasonic probe for seismic application is made so that the relative incident angle θ approaches 90 °. The vibration ultrasonic probes 40 and 42 may be inclined and installed so that the central axes of the transducers 41 and 43 of the elements 40 and 42 intersect with each other.

  In this case, the directivity angle φ of the ultrasonic wave is as small as less than 45 °, and it is difficult to reduce the distance L because the casings of the ultrasonic transducers 40 and 42 for vibration are relatively large. Also, the distance X from each transducer 41, 43 of the ultrasonic transducers 40, 42 for earthquake to the concrete structure 1 and the height H from the upper end 23 of the outer wall 22 of the water tank portion 20 to a small amplitude Can be increased. If the height H to the upper end 23 of the outer wall 22 can be reduced, the water tank portion 20 can be made smaller, and it is possible to conduct a good foreign substance inspection while configuring the foreign substance inspection device 10 as a whole as a whole.

In the case where the seismic transducer 40, 42 is installed at an angle such that the relative incident angle θ is 90 °, it is assumed that φ = 70 × λ / D = 45 ° in the above equation (1), In the above equation (2), tan (70 × λ / D) = tan 45 ° = 1 can be obtained to obtain the following equation (3).
2 × X> L−D (3)

  The ultrasonic transducer 50 for vibration receiving is a probe that receives a reflected wave of ultrasonic waves reflected from the ultrasonic transducers 40 and 42 for earthquake emission toward the concrete structure 1 and reflected inside the concrete structure 1 It is a child and has the receiving part 51 in the lower surface. The receiving ultrasonic probe 50 is suspended on the rail 30 via the slide bracket 34, and is configured to be movable along the rail 30 independently of the seismic ultrasonic probes 40 and 42. ing. At the time of foreign substance inspection, at least the receiving portion 51 of the receiving ultrasonic probe 50 is also immersed in the water 28 stored in the water tank portion 20. Although the distance X from each of the transducers 41 and 43 to the concrete structure 1 is taken as the distance X for the vibration ultrasonic probes 40 and 42, the concrete structure 1 from the vibration receiving portion 51 for the vibration receiving ultrasonic probe 50. The distance up to the point may be the above distance X, and is not limited to the distance X and may be arbitrary. For example, the receiving ultrasonic probe 50 may be brought into contact with the surface of the concrete structure 1.

  In the figure, "T" attached to the seismic probe 40 for vibration means transmission, and "R" attached to the ultrasonic probe 50 for vibration reception means vibration reception. Further, since the vibration detecting ultrasonic probes 40 and 42 and the receiving ultrasonic probe 50 are well-known waterproofed, the description of the details of the configuration thereof will be omitted.

  The control unit 60 outputs a seismic signal to the seismic ultrasonic probes 40 and 42 and receives a pulsating signal from the ultrasonic transducer 50 and the digital signal and the pulsating signal. AD board 64 that converts between signals and analog signals, an earthquake waveform control unit (control device, control unit) 72 that performs earthquake waveform control including phase control and frequency control of earthquake signals, and signal processing of vibration signals And a control PC (personal computer) 70 having a received signal processing unit (analyzing device, analyzing unit) 74 for recognizing foreign objects and an image of data obtained by monitoring or processing a seismic signal and a received signal. And a monitor 80 for displaying and the like.

Hereinafter, the operation of the foreign matter inspection apparatus 10 configured as described above will be described.
Referring to FIG. 4, the conversion condition from longitudinal waves to transverse waves on the surface of the concrete structure 1 of the ultrasonic waves generated by the ultrasonic transducers 40 and 42 for generation is schematically shown in FIG. 5 and, with reference to FIG. 5, the receiving situation (a) and its details (b) by the receiving ultrasonic probe 50 of the receiving wave of the reflected wave reflected inside the concrete structure 1 are schematically shown. There is.

  From the vibration ultrasonic probes 40 and 42, ultrasonic waves having the same frequency and the same intensity and the same characteristics are generated. At this time, as schematically shown by a solid line (+) and a broken line (-) in FIG. 4A, ultrasonic waves having different phases in the ultrasonic transducer 40 for vibration generation and the ultrasonic transducer 42 for vibration generation Is struck.

  That is, in the seismic waveform control unit 72 of the control PC 70 of the control unit 60, a phase difference is given between the ultrasonic wave from the seismic ultrasonic probe 40 and the ultrasonic wave from the seismic ultrasonic probe 42. (Control step) The ultrasonic wave is emitted from the ultrasonic probe 42 for earthquake generation with a phase shift with respect to the ultrasonic wave emitted from the ultrasonic probe 40 for earthquake generation (shock generation step). In fact, here, the ultrasonic wave from the seismic transducer 40 (indicated by +) is shifted in phase by half a cycle from the ultrasonic transducer 42 for seismic, that is, the ultrasonic waves in opposite phase are The earthquake (indicated by-) is triggered.

  As described above, the ultrasonic waves emitted from the ultrasonic transducers 40 and 42 with different phases respectively propagate as longitudinal waves (compression waves) in water, and the surface of the concrete structure 1 has a relative incident angle θ. Overlap. At the time of FIG. 4 (a), on the surface of the concrete structure 1, as shown in detail in FIG. 4 (b), the vibration ultrasonic waves shown by the solid line (+) in FIG. 4 (a) As for the ultrasonic waves from the probe 40, a shear component is generated to push the surface of the concrete structure 1 in the right direction of the drawing (solid arrow), and from the ultrasonic transducer 42 for earthquake shown by the broken line (-) In the case of ultrasonic waves, a shear component (broken line arrow) such as pulling the surface of the concrete structure 1 in the right direction of the drawing occurs. That is, since the density of the density in the traveling direction of the ultrasonic wave which is the longitudinal wave differs depending on the phase difference of the ultrasonic wave, one is a traveling wave and the other is a receding wave, and the surface of the concrete structure 1 is amplified in the same direction. Shear component is generated (open arrow).

  The shear component generated by the ultrasonic waves overlapping on the surface of the concrete structure 1 in this manner gradually changes in the left direction of the drawing, and vibration is repeated in the right direction and the left direction as time passes, and a transverse wave of constant amplitude ( Shear waves are generated. Then, this transverse wave propagates inside the concrete structure 1. Since ultrasonic waves having the same frequency and the same intensity are generated from the seismic transducers for vibration 40 and 42 respectively, shear components generated on the surface of the concrete structure 1 by the ultrasonic waves are uniform in the left and right direction, Therefore, this transverse wave propagates inside the concrete structure 1 in the direction perpendicular to the surface of the concrete structure 1.

  The ultrasonic transverse wave, which is generated in this manner and propagates in the interior of the concrete structure 1 in the direction perpendicular to the surface of the concrete structure 1, is shown in FIG. 5 if there is a reflection source such as foreign matter inside the concrete structure 1. As shown to (a), it reflects as a reflected wave in the perpendicular direction as it is, and returns to the surface of the concrete structure 1. FIG. At this time, since the reflected wave is also a transverse wave, the surface of the concrete structure 1 vibrates to the left and right, and the water 28 vibrates to the left and right. However, since transverse waves do not propagate in water, longitudinal waves (compression waves) obliquely directed to the surface of the concrete structure 1 are generated in water (solid arrows). More specifically, as shown in FIG. 5 (b), the reflected wave from the inside of the concrete structure 1 is directed obliquely from the surface of the concrete structure 1 to the left and right, in the direction along the surface of the concrete structure 1 A longitudinal wave (solid arrow) is generated in the water 28 so as to be maximum and minimum in the vertical direction.

  And the reflected wave from the inside of the concrete structure 1 converted into the longitudinal wave is received by the receiving ultrasonic probe 50 (a receiving step). In FIG. 5 (a), unlike the case of FIG. 1 above, a plurality of the receiving parts 51 are arranged in the direction along the surface of the concrete structure 1, and each receiving part 51 reflects waves different in receiving strength. The ultrasonic transducer 50 for vibration receiving illustrated at once is illustrated. In the case of the receiving ultrasonic probe 50 having a single receiving portion 51 shown in FIG. 1 described above, the receiving ultrasonic probe 50 is placed along the rail 30 at a predetermined interval P (see FIG. 8) in order The reflected wave may be received at a plurality of points while moving. Here, the fixed interval P is appropriately set according to the thickness of the concrete structure 1 or the like. In addition, it is possible to comprise a system cheaply by comprising the foreign material test | inspection apparatus 10 with the ultrasonic probe 50 for vibration receiving which has the single vibration receiving part 51 shown in FIG.

  When the inspection at one place of the concrete structure 1 is completed, the seismic transducer 40 for earthquake application is moved along the rail 30, and the inspection is sequentially performed.

  The reflected wave received by the receiving ultrasonic probe 50 is subjected to signal processing and analysis in the received signal processing unit 74 of the control PC 70 of the control unit 60 (analysis step). For example, data processed by the signal is, for example, a concrete structure It is displayed on the monitor 80 as an image in the depth direction of the object 1. Thus, based on the image displayed on the monitor 80, it is possible to analyze the position and the size in the depth direction of the foreign matter present inside the concrete structure 1.

  Then, the series of inspections described above are repeatedly performed by moving the rail 30. Thereby, the position and size of the foreign material which exists in the inside of concrete structure 1 in the plane direction can also be analyzed.

  As described above, in the foreign matter inspection apparatus 10, the ultrasonic waves generated as longitudinal waves (compression waves) in water from the ultrasonic transducers 40 and 42 for generation are converted into shear waves (shear waves) on the surface of the concrete structure 1 By propagating this transverse wave in the concrete structure 1 in the direction perpendicular to the surface of the concrete structure 1, it is possible to analyze the presence of foreign matter. Thereby, the position and size of the foreign matter can be analyzed well. That is, as described above, in the case of ultrasonic waves of longitudinal waves (compression waves), it is difficult to obtain a reflected wave from the bottom of the pore because it is mainly reflected only on the upper surface of the pore, and as a result exists in the pore There is a problem that although the position of the upper surface of the foreign object can be analyzed, the position of the lower surface of the foreign object can not be specified, but in the case of a transverse wave, it is difficult to be affected by this pore and therefore the upper surface as well as the bottom of the pore It is easy to obtain the reflected wave from the above, and the position and size of the foreign matter present inside the concrete structure 1 can be analyzed well.

  In addition, as described above, when a seismic transducer for vibration application is installed on the surface of a concrete structure and ultrasonic waves are incident at an oblique angle so as to generate a transverse wave in the concrete structure, If the surface has irregularities or the like, the refraction angle is not stabilized and the incident intensity of the ultrasonic wave is reduced, which makes it difficult to propagate the transverse wave perpendicular to the surface of the concrete structure. However, in the foreign matter inspection apparatus 10, it is possible to generate a shear wave (shear wave) on the surface of the concrete structure 1 by superimposing ultrasonic waves of a pair of longitudinal waves (compression waves) propagating in water. It is not necessary to consider the angle of refraction of the sound wave itself, and therefore ensure a transverse wave perpendicular to the surface of the concrete structure 1 inside the concrete structure 1 without being affected by the unevenness of the surface of the concrete structure 1 or the like. Can be propagated to Thereby, the stable reflected wave without dispersion can be received by the receiving ultrasonic probe 50, and the position and size of the foreign matter present inside the concrete structure 1 can be analyzed with high accuracy.

  In the above-described embodiment, the vibration ultrasonic probes 40 and 42 and the vibration receiving ultrasonic probe 50 are configured to be moved along the rails 30, for example, manually. The probes 40 and 42 and the ultrasonic probe 50 for receiving vibration may be configured to be automatically movable along the rails 30.

  Further, in the above embodiment, although the vibration ultrasonic probes 40 and 42 and the vibration receiving ultrasonic probe 50 are configured to be movable in one dimension, for example, in one direction along the rail 30, the vibration ultrasonic probe The rails (support members) may be configured to be movable in two dimensions by the feelers 40 and 42 and the ultrasonic probe 50 for vibration receiving.

  Further, in the above embodiment, the lower end periphery of the outer wall 22 of the water tank 20 is provided with, for example, a soft resin or a soft rubber material, etc. to prevent leakage of the water 28 stored in the water tank 20 to the outside. However, the lower end periphery of the outer wall 22 does not necessarily have to be provided with a soft resin or a soft rubber material or the like. In this case, the water 28 in the water tank portion 20 is likely to leak to the outside, but the transducers 41 and 43 of the vibration ultrasonic probes 40 and 42 and the vibration receiving portion 51 of the vibration receiving ultrasonic probe 50 The water 28 may be continuously supplied to the water tank 20 so that the water 28 is always immersed in the water 28.

  In the above embodiment, the foreign matter inside the concrete structure 1 is inspected by storing water in the water tank portion 20, for example, in the case where the surface of the concrete structure 1 faces upward. Even in the case where the surface of the concrete structure 1 faces in the lateral direction or downward direction, for example, even on a bridge or the like constructed in the sea or a river, the inspection is properly performed using the foreign substance inspection device 10 be able to. That is, in the case of a bridge or the like constructed in the sea or a river, since the periphery is filled with water, the water tank unit 20 is filled with water only by installing the water tank unit 20 on the surface of the concrete structure 1 The foreign substance inspection apparatus 10 can be applied.

  In the above embodiment, the control unit 60 controls the ultrasonic waves generated by the ultrasonic transducers 40 and 42 to generate a phase difference. It is also possible to provide a phase difference to the ultrasonic waves by making the distance between the transducer 40 of the feeler 40 and the distance from the surface of the concrete structure 1 to the transducer 43 of the ultrasonic transducer 42 for earthquake occurrence different. .

  Moreover, although the water was stored in the water tank part 20 in the said embodiment, the liquid stored in the water tank part 20 is not restricted to water.

  Moreover, in the said embodiment, although the foreign material test | inspection apparatus 10 was comprised using a pair of ultrasonic transducer for earthquakes as a pair of ultrasonic transducer 40 for earthquakes, the ultrasonic transducer for vibration is It is also possible to be configured with a plurality of three or more. Thereby, it is possible to freely change the waveform of the shear wave.

Referring to FIG. 6, a foreign matter inspection apparatus 10 'is shown as a modification.
Although the foreign substance inspection apparatus 10 'has the same basic configuration as the foreign substance inspection apparatus 10, the water tank part 20' has a frame-like outer wall 22 and a bottom part 26 together. That is, in the foreign matter inspection device 10 ′, the water tank portion 20 ′ is configured such that the bottom portion 26, not the water, contacts the surface of the concrete structure 1.

  The bottom portion 26 is formed of a member that is in close contact with the surface of the concrete structure 1 and does not slip on the surface of the concrete structure 1. Here, the bottom portion 26 is made of, for example, a rubber material.

  As described above, when the foreign substance inspection apparatus 10 ′ having the water tank part 20 ′ having the bottom part 26 is used, the water tank part 20 ′ can be moved in a state where water is stored in the water tank part 20 ′. Installation on the surface of the concrete structure 1 is facilitated, and the workability of foreign matter inspection is improved.

  In addition, even in the foreign matter inspection apparatus 10 'provided with the water tank portion 20' having the bottom portion 26 in this manner, the ultrasonic waves of the longitudinal waves generated from the seismic transducers 40 and 42 for propagation in water are The surface wave of the bottom portion 26 or the surface of the concrete structure 1 is favorably converted into a transverse wave, and propagates to the inside of the concrete structure 1 as a transverse wave, and the same effect as described above can be obtained.

  As shown in FIG. 7, the concrete structure 101 of 2000 mm long, 2000 mm wide and 1500 mm thick having a sand layer A, a sand layer B and a sand layer C as foreign substances inside is shown in FIG. It checked using.

  Sand layer A and sand layer B are each 500 mm long, 500 mm wide and 50 mm thick, and each have a distance of 500 mm at a position of 300 mm from the surface of concrete structure 101 and against the surface of concrete structure 101 It was made to be parallel.

  Sand layer C is a layer of 1000 mm long, 1000 mm wide and 50 mm thick, partially overlapping with sand layer A and sand layer B in the vertical direction, and the central portion is positioned 750 mm from the surface of concrete structure 101 It was made to be inclined at 10 ° to the surface of the object 101.

  The configuration of the foreign matter inspection apparatus 10 is as described above, the diameter D of each of the transducers 41 and 43 of the ultrasonic transducers 40 and 42 for oscillation is 40 mm, and the frequency of ultrasonic waves is 100 kHz. The distance L which is the center-to-center distance of 43 is set to 50 mm based on the above equations (1) and (2), and from the transducers 41 and 43 of the ultrasonic transducers 40 and 42 for earthquake application to the concrete structure 1 The distance X was set to 30 mm. Also, the receiving ultrasonic probe 50 is configured to have a single receiving unit 51. Then, the water 28 was stored in the water tank portion 20, and the ultrasonic transducers 40 and 42 for vibration application and the ultrasonic transducer 50 for vibration reception were completely immersed in water.

  In the examination, an ultrasonic wave of 100 kHz is generated from the ultrasonic transducer 40 for earthquake occurrence, 42, and as shown in a schematic diagram of the flow of the examination in FIG. 8, the ultrasonic probe 50 for vibration reception is fixed at 6.25 mm. The operation of receiving the reflected wave at 64 points while moving sequentially by the interval P is repeated while moving the ultrasonic transducers 40 and 42 for oscillation at a constant interval of 6.25 mm, and this series of operations is further performed by the rail 30 Was moved repeatedly. As shown in FIG. 7, the movement range of the seismic probe 40 for earthquake generation in this series of operations is set to a range of 1250 mm from the position S1 to the position S2.

  FIG. 9 shows an image in which the received wave received by the receiving ultrasonic probe 50 in the above inspection is subjected to signal processing in the control PC 70 of the control unit 60, and the data in the depth direction is displayed on the monitor 80.

  According to FIG. 9, the upper surfaces of the sand layer A and the sand layer B can be clearly confirmed at a position near 300 mm from the surface of the concrete structure 101, and the lower surfaces of the sand layer A and the sand layer B are confirmed at a position near 350 mm to 450 mm from the surface. it can. Further, the inclined upper surface of the sand layer C can be confirmed at a position near 650 mm to 800 mm from the surface of the concrete structure 101, and the inclined lower surface of the sand layer C can be confirmed at a position near 700 mm to 900 mm from the surface.

  In FIG. 10, as a comparative example, using the foreign matter inspection apparatus 10 of FIG. 1 with respect to the concrete structure 101, for example, ultrasonic waves of longitudinal waves (compression waves) from transverse ultrasonic probes 40, 42 In the same phase to generate a vertical wave on the surface of the concrete structure 101, ultrasonic waves of longitudinal waves are propagated inside the concrete structure 101, and the reflected waves of the longitudinal waves are signal-processed, and the depth direction 8 shows an image when the data of are displayed on the monitor 80 as in FIG.

  According to FIG. 10, when ultrasonic waves of longitudinal waves are allowed to propagate inside the concrete structure 101, although the upper surfaces of the sand layer A and the sand layer B can be confirmed at a position near 200 mm from the surface of the concrete structure 101 Although it is unclear about each lower surface of A and sand layer B, although a part of upper surface of sand layer C can be confirmed at a position near 450 mm to 500 mm from the surface of concrete structure 101, it is unclear about the lower surface of sand layer C . That is, when ultrasonic waves of longitudinal waves are propagated to the inside of the concrete structure 101, although it is possible to confirm a part considered to be the upper surface of the sand layer A and the sand layer B or a part of the part considered to be the upper surface of the sand layer C. Their positions are incorrect, and none of the sand layer A, the sand layer B and the sand layer C can identify the position of the lower surface.

  As described above, when a transverse wave is generated and propagated inside the concrete structure 101 by the foreign matter inspection device 10, it is reliably compared to the case where the ultrasonic wave of the longitudinal wave is propagated inside the concrete structure 101. It was confirmed that it was possible to detect foreign matter.

1, 101 Concrete structure 10, 10 'Foreign matter inspection device 20, 20' Water tank part (liquid tank part)
22 outer wall 26 bottom 28 water (liquid)
30 rails (support members)
40, 42 Vibrational Ultrasonic Probes (Ultrasonic Probes)
41, 43 Transducers 50 Ultrasonic Transducers for Acoustic Reception (Receiver)
51 Receiver 60 Control Unit 70 Control PC
72 Seismic waveform control unit (control device, control unit)
74 Received Signal Processing Unit (Analyzer, Analysis Unit)
80 monitors

Claims (8)

Liquid that dips part or all of the surface of the concrete structure,
A plurality of ultrasonic probes, each of which is provided so as to be immersed in the liquid, and which emits ultrasonic waves consisting of compression waves toward the concrete structure from each of the plurality of ultrasonic probes;
A receiver provided so as to be immersed in the liquid, and configured to receive a reflected wave of the ultrasonic wave;
A control device for controlling the phases of the ultrasonic waves respectively generated from the plurality of ultrasonic probes;
And an analysis device for analyzing the received information from the receiver and recognizing foreign matter in the concrete structure,
The control device is configured to generate a shear wave on the surface of the concrete structure so that the shear wave propagates in the interior of the concrete structure, the ultrasonic waves are generated between the plurality of ultrasonic probes. Give a phase difference to
The above-mentioned geophone is a concrete structure which is reflected inside the concrete structure, converted from shear wave to compressional wave on the surface of the concrete structure, and receives ultrasonic waves propagating in the liquid as a reflected wave. Foreign substance inspection system.   The foreign matter inspection system for a concrete structure according to claim 1, wherein the control device applies a half cycle phase difference between the ultrasonic waves oscillated respectively from the plurality of ultrasonic probes.   The plurality of ultrasonic probes are each of the plurality of ultrasonic probes such that the ultrasonic waves generated by the plurality of ultrasonic probes overlap each other on the surface of the concrete structure. The foreign matter inspection system for a concrete structure according to claim 1 or 2, wherein a distance between the vibrators and a distance from each of the vibrators to the surface of the concrete structure are set.   The foreign matter inspection system for a concrete structure according to any one of claims 1 to 3, wherein the plurality of ultrasonic probes are a pair of ultrasonic probes. A frame-like liquid tank portion which is placed on the surface of the concrete structure and which holds the liquid on the surface;
The vibrators are provided in parallel so as to be exposed to the surface of the concrete structure and immersed in the liquid stored in the liquid tank, and a pair of earthquakes that generate ultrasonic waves from the vibrators toward the concrete structure Ultrasonic probe,
A receiving ultrasonic probe provided so as to be immersed in the liquid and receiving the reflected wave of the ultrasonic wave;
A support member for movably supporting the pair of vibration ultrasonic transducers and the receiving ultrasonic transducers along the surface of the concrete structure;
A control unit configured to control the phase of the ultrasonic waves respectively generated from the pair of ultrasonic transducers for vibration generation;
An analysis unit that analyzes received information from the receiving ultrasonic probe to recognize foreign matter in the concrete structure;
Foreign matter inspection device for concrete structures, equipped with   The receiving ultrasonic probe has one receiving part and is supported by the supporting member so as to be movable independently of the pair of seismic ultrasonic probes. Foreign matter inspection device for a concrete structure as described above.   The foreign matter inspection apparatus for a concrete structure according to claim 5, wherein the liquid tank portion is configured to have a bottom portion in close contact with the surface of the concrete structure. A control step of controlling the phases of the ultrasonic waves generated respectively from the plurality of ultrasonic probes;
Control of the phase from each of the transducers of the plurality of ultrasonic probes provided so as to be immersed in a liquid for immersing each or part of the surface of the concrete structure to the concrete structure Process of emitting ultrasonic waves consisting of compressed waves,
A receiving step of receiving a reflected wave of the ultrasonic wave by a receiver provided so that the receiver is immersed in the liquid;
And analyzing the received information from the receiver and recognizing foreign matter in the concrete structure.
In the control step, a phase difference is provided between the ultrasonic waves so that shear waves are generated on the surface of the concrete structure and the shear waves propagate inside the concrete structure;
In the receiving process, the concrete structure receives an ultrasonic wave which is reflected inside the concrete structure and converted from a shear wave to a compressional wave on the surface of the concrete structure and propagates in the liquid as a reflected wave. Foreign substance inspection method.