JP7113428B2 - Nondestructive testing equipment for structures - Google Patents

Description

The present invention relates to elastic deformation of defective portions (deformed portions) such as cracks, cavities, and deterioration occurring in structures such as concrete, and internal defects occurring in metal structures such as iron bridges integrated with concrete. The present invention relates to a technique for inspection by non-destructive testing using waves, etc., and more particularly to a non-destructive testing apparatus for structures comprising a testing apparatus unit having an impact hammer and a plurality of receiving devices so as to enable inspection over a wide range.

Many concrete structures are large structures such as tunnels and bridges. Defects in concrete are subject to evaluation, including the depth of bending and cracking, the degree of injection material filling, cracks inside the concrete due to fatigue, the condition of the reinforced concrete interface due to corrosion of reinforcing bars, and the degree of filling of PC grout (prestressed concrete injection material). Become. Furthermore, cavities may occur in concrete structures over a long period of time due to various factors. The existence of such cavities has a great influence on deterioration of strength of concrete structures, and detection of cavities is important for maintenance of concrete structures.

Bridges such as steel bridges and concrete bridges are also subjected to various inspections for their maintenance. Metal structures of steel bridges are inspected by various non-destructive tests. For example, for testing abnormalities, surface flaws and internal defects of metal structures, ultrasonic testing (vertical, oblique angle, SH wave, etc.), ultrasonic thickness measurement, magnetic particle testing, penetrant testing, crack depth gauge A crack depth inspection, an AE inspection, and a coating film performance inspection using a coating film deterioration sensor are carried out.

Physical properties and defects related to concrete are tested or inspected by various test methods. It is necessary to clarify the characteristics and roles of elastic wave propagation characteristics (propagation velocity, amplitude and frequency spectrum) as evaluation indexes in physical property and defect evaluation of concrete. Regarding the physical properties of this concrete, the setting and hardening properties of cement are evaluated.

There are various non-destructive testing methods for cement setting properties, bending, cracking, and depth. Furthermore, there are various non-destructive testing methods for checking the filling degree of grout, cracking inside concrete due to fatigue, and conditions at the interface of reinforced concrete due to corrosion of reinforcing bars. For example, non-destructive tests using elastic waves include the impact elastic wave method and the ultrasonic method. In addition, there is a hammering method in which elastic waves are generated in concrete by hammering and the waves radiated from the concrete surface into the air are measured. This hammering method is used to detect cracks and spalling in concrete, and internal void areas. Furthermore, there is an acoustic emission (AE Acoustic Emission) method in which elastic waves generated and propagated by cracks in concrete are detected and detected by installing an AE transducer (sensor) on the concrete surface. This AE method is used to detect the location of crack initiation and propagation in concrete.

The impact acoustic wave method uses a hammer, steel ball, etc. as an input device. This input device is mainly driven by human work. An acceleration sensor, an AE sensor, or the like is used as the receiving device. The acoustic waves of this test method have the properties of long wavelength and high energy. Although it is difficult to input reproducible elastic waves in this test method, there are many results in actual structures.

On the other hand, the ultrasonic method uses a probe, an AE sensor, etc. as an input device. This input device is driven by voltage control. A probe, an AE sensor, or the like is used as the receiving device. The elastic wave of this test method has the properties of short wavelength and low energy. This test method can input reproducible elastic waves, but there are few actual results in actual structures.

As a technique related to non-destructive testing of physical properties and defects of concrete by the impact elastic wave method, for example, as in Patent Document 1, Japanese Patent Application Laid-Open No. 2000-131290 "Concrete Non-Destructive Inspection Apparatus", it is generated from concrete to which external force is applied. signal detection means for detecting the vibration as a vibration signal; conversion means for converting the vibration signal into a time-series signal for each of a plurality of predetermined frequency bands; and extracting the maximum value of the time-series signal for each frequency band. A concrete non-destructive inspection apparatus has been proposed that includes an extraction means and a comparison means for comparing each of the maximum values with a preset vibration reference value for each frequency band.

Japanese Patent Application Laid-Open No. 2000-131290

As described above, the impact acoustic wave method is easy to measure, and since the input elastic wave has a long wavelength and high energy, it is difficult to attenuate, and is often used for measurement of actual concrete structures. However, since a hammer or a steel ball is used to input elastic waves, it is difficult for the hitting force to be uniform depending on the person hitting the ball, and measurement errors are likely to occur.

Concrete structures such as tunnels require a wide range of inspection points. For example, railroad tunnels have had to undergo extensive non-destructive testing in the short time between the last train and the first train. Motorway tunnels had to be closed to some vehicles during inspection hours. The "concrete non-destructive inspection apparatus" of Patent Document 1 has a problem that such wide-ranging inspection cannot be smoothly processed within a predetermined time.

It is conceivable to operate a large number of nondestructive testing devices at the same time, but the number of operators involved in the operation increases, resulting in increased work costs. In some cases, it is not possible to accurately test a concrete structure such as a tunnel by simply connecting a plurality of non-destructive testing devices because the concrete structure has curved surfaces.

The present invention has been created to solve such problems. That is, the object of the present invention is to unitize and connect a plurality of nondestructive testing devices, so that nondestructive testing can be performed in a wide range at the same time, and any vertical wall surface, ceiling surface or floor surface To provide a non-destructive testing device for a structure capable of striking a surface of a structure such as a concrete wall surface with an impact hammer at an appropriate angle and receiving elastic waves, and having high test accuracy. .

A first aspect of the present invention is a nondestructive testing apparatus (1) for structures for nondestructively testing a structure (C) using a plurality of impact hammers (3),
a striking hammer (3) for inputting an elastic wave into the structure (C); a receiver (4) for receiving the elastic wave propagated through the structure (C) by the striking of the striking hammer (3); a percussion test unit (2) consisting of
A movable support member (2) to which each impact test unit (2) is movably attached so that the impact hammers (3) of the multiple impact test units (2) are shifted in adjacent rows and arranged at a constant pitch. 7) and
The impact test unit (2) is a triangular arrangement of one impact hammer (3) and two receivers (4), and the two receivers (4) are connected to the structure ( In order to correspond to the wide and narrow measurement range of C), the receiving devices (4) are movably arranged at intervals,
Since the striking hammers (3) and the receiving device (4) are close to each other, the elastic waves propagated within the structure (C) due to the impacts of the striking hammers (3) can be easily received. Characterized by

The two receivers (4) are movably arranged at a distance from the impact hammer (3) so as to correspond to the depth of the deformed portion in the structure (C). can do.
Each impact test unit (2) is attached to the movable support member (7) so that the angle of each impact test unit (2) with respect to the surface of the structure (C) can be varied individually. can do.

A second aspect of the present invention is a structure nondestructive testing apparatus (31) for nondestructively testing a structure (C) using a plurality of impact hammers (3),
a striking hammer (3) for inputting an elastic wave into the structure (C); a receiver (4) for receiving the elastic wave propagated through the structure (C) by the striking of the striking hammer (3); a percussion test unit (2) consisting of
a spacing adjustment support (32) to which each impact test unit (2) is attached so that the spacing between the plurality of impact test units (2) can be adjusted;
Depending on the object of the non-destructive test, the interval between each impact test unit (2) is narrowed when inspecting the structure (C) in detail, and the interval between each impact test unit (2) when inspecting a wide range It is characterized in that it is configured so that the

A third aspect of the present invention is a structure nondestructive testing apparatus (41) for nondestructively testing a structure (C) using a plurality of impact hammers (3),
a striking hammer (3) for inputting an elastic wave into the structure (C);
a receiving device (4) for receiving elastic waves propagated in the structure (C) by the impact of the impact hammer (3);
a device support (42) to which each striking hammer (3) and receiving device (4) are mounted so as to adjust the distance between a plurality of said striking hammers (3) and said receiving devices (4);
Depending on the object of the non-destructive test, when inspecting the structure (C) in detail, the distance between the impact hammer (3) and the receiving device (4) is narrowed, and when inspecting a wide range, the impact hammer (3) and the receiving device (4) are arranged so that the distance between them can be widened.

In the configuration of the first aspect of the present invention, a plurality of impact test units (2) can carry out impact tests on the structure (C) over a wide range at the same time.
Since each impact test unit (2) is staggered on a movable support member (7) and the impact hammer (3) and the receiving device (4) are in close proximity, the impact of the impact hammer (3) on said structure (C) ) The receiving device (4) can reliably receive the elastic waves generated on the surface.
If the impact test unit (2) can individually vary the angle with respect to the surface of the structure (C), the impact hammer (3) impacts the surface of the curved structure (C) at an appropriate angle, Moreover, the receiving device (4) can reliably receive the elastic waves. As a result, the accuracy of the impact test is enhanced.

In the configuration of the second aspect of the present invention, the intervals between the impact test units (2) are arranged so as to be adjustable, so that they can be appropriately adjusted according to the impact test target of the impact hammer (3). When inspecting in detail, the impact test can be conducted by narrowing the interval between the impact test units (2) and arranging them.

In the configuration of the third aspect of the present invention, the spacing between the striking hammer (3) and the receiving device (4) is arranged so that it can be adjusted. be able to. When inspecting in detail, an impact test is performed by narrowing the distance between the impact hammer (3) and the receiving device (4). A highly accurate impact test is possible.

1 is a partially cutaway plan view showing a non-destructive testing device for a structure in which the impact test unit of Example 1 is arranged horizontally. FIG. 1 is a partially cutaway front view showing a non-destructive testing device for a structure in which the impact test unit of Example 1 is arranged horizontally. FIG. FIG. 2 is an enlarged cross-sectional plan view showing an example of the impact test unit that constitutes the non-destructive testing device for structures of Example 1; 3 is a block diagram showing a control device that controls each impact test unit 2. FIG. FIG. 10 is an enlarged cross-sectional plan view showing Modification 1 of the impact test unit that constitutes the non-destructive testing device for structures of Example 1; FIG. 11 is an enlarged plan cross-sectional view showing Modification 2 of the impact test unit that constitutes the nondestructive testing device for structures of Embodiment 1; FIG. 10 is a schematic plan view showing a non-destructive testing apparatus for structures of Example 2, in which a plurality of impact test units are horizontally arranged so as to be adjustable in position; FIG. 10 is a schematic plan view showing a non-destructive testing apparatus for structures of Example 3 in which a plurality of impact hammers and a plurality of receiving devices are horizontally arranged so as to be positionally adjustable;

A non-destructive testing apparatus for structures according to the present invention comprises an impact hammer for inputting elastic waves into a structure such as concrete, and a receiving device for receiving the elastic waves propagated through the structure by the impact of the impact hammer. The apparatus includes a unit and a movable support member to which each impact test unit is mounted so that the impact hammers of a plurality of impact test units are staggered in adjacent rows and arranged at a constant pitch.

<Configuration of non-destructive testing equipment>
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partially cutaway plan view showing a non-destructive testing apparatus for structures in which the impact test units of Example 1 are arranged horizontally. FIG. 2 is a partially cutaway front view showing a non-destructive testing apparatus for structures in which the impact test unit of Example 1 is arranged horizontally. FIG. 3 is an enlarged plan cross-sectional view showing an example of the impact test unit that constitutes the non-destructive testing apparatus for structures of Example 1. FIG.
A structural non-destructive testing apparatus 1 of Example 1 has a laterally long impact testing unit 2 for non-destructive testing by the impact acoustic wave method. Each impact test unit 2 uses an impact hammer 3 as an input device and an acceleration sensor or the like as a receiving device 4 . In particular, the impact test unit 2 has one impact hammer 3 and two receivers 4 arranged in a substantially triangular shape. The impact test unit 2 is a unit in which one impact hammer 3 and two receivers 4 are arranged. This is because the arrangement of one striking hammer 3 and two or a plurality of receiving devices 4 naturally becomes a triangular or polygonal arrangement. This is the minimum number for face placement.

The receiving device 4 receives the elastic wave propagated within the concrete structure C of the test object by the impact of the impact hammer 3 in each impact test unit 2 . The received elastic wave is analyzed for reflected echo, wave frequency, phase, etc., and the presence or absence of a defect CR inside the structure C such as concrete, the back cavity S, and the distance to the position of the defect CR are measured. Further, the deformed portion (abnormal portion) is marked by the marking device 5 for confirmation and repair at a later date.

Although the concrete structure C is described in these examples, the inspection object of the present invention is not limited to this concrete structure C. Metal structures such as steel bridges are also subject to inspection.

When the non-destructive testing device is a testing device based on the ultrasonic method, a probe, an AE sensor, etc. are used as input devices, although not shown. This input device is driven by voltage control. A probe, an AE sensor, or the like is used as the receiving device.

The impact hammer 3 in each impact test unit 2 is a device that strikes the concrete structure C and inputs the generated elastic waves into the concrete structure C. As shown in FIG. A striking hammer 3, for example, a hammer head 6 which is slidable in a cylindrical body, and an elastic member such as a coil spring attached to pull back or press the hammer head 6 are accommodated, and a solenoid is provided in the cylindrical body. It is. This solenoid is actuated to reciprocate the hammer head 6 .

As shown in FIGS. 1 and 2, the structural non-destructive testing apparatus 1 of Example 1 has impact hammers 3 of a plurality of impact test units 2 attached to a movable support member 7 in a so-called "staggered arrangement". ing. That is, each impact test unit 2 is attached to the movable support member 7 so that the positions of adjacent rows are shifted and arranged at a constant pitch. The movable support member 7 is a member that holds the substantially triangular casing 8 of the impact test unit 2 so as to wrap it. The structural nondestructive testing apparatus 1 of Example 1 has a plurality of impact test units 2 arranged in a rectangular shape on a movable support member 7 . In this way, each impact test unit 2 has the impact hammers 3 and the receiving devices 4 arranged in a staggered manner, so that the elastic waves propagated within the structure C due to the impact of the impact hammers 3 are received. Cheap.

<Configuration of control device for controlling non-destructive testing device>
FIG. 4 is a block diagram showing a control device for controlling each impact test unit 2. As shown in FIG.
An amplification processing section 12 (AMP) and a control signal input section 13 are connected to the input side of the control device 11 that controls each impact test unit 2 of the first embodiment. The amplification processing unit 12 (AMP) amplifies the detection signal of the elastic wave received by the receiving device 4 (acceleration sensor).

An output side of the control device 11 is connected to an impact hammer operation signal output section 14 for operating the impact hammer 3 and a display processing section 15 . An LED or the like is connected to the display processing unit 15 . It informs the current operating state. The signal processing unit 16 processes the amplification processing unit 12 (AMP) that amplifies the detection signal of the receiving device 4 (acceleration sensor) to perform each operation on the output side.

Furthermore, a marking operation signal output section 17 for marking by the marking device 5 is connected to the output side of the control device 11 . The signal processing unit 16 also processes the detection signal of the receiving device 4 (acceleration sensor) on the input side to perform each operation.

A plurality of impact test units 2 are used in combination. Therefore, in the case of the rectangular impact test unit 2, it can be connected as a "line" so as to be long. On the other hand, in the case of the square-shaped impact test unit 2, it can be connected so as to spread out as a "surface".

The nondestructive testing apparatus 1 including each impact test unit 2 is first installed on the surface of the structure C which is the object to be inspected. In the case of a tunnel, the non-destructive testing device 1 is supported by a support device and moved while impact testing is performed on the vertical walls and ceiling of the tunnel. At this time, the support device includes an elevating device, an arm, and the like provided on the carriage. Furthermore, it may be of a type in which a sucker-like device is used to freely run on the inner wall surface of the tunnel.

The hammer head 6 of the impact hammer 3 of the impact test unit 2 is brought into contact with the surface of the structure C, and the impact hammer 3 is operated. An elastic wave is generated by the impact of the impact hammer 3 and is input into the structure C.

The elastic wave input to the structure C in this way propagates within the structure C. As shown in FIG. This propagated elastic wave is received by the receiving device 4 (acceleration sensor). Analyze the reflected echo, wave frequency, phase, etc. of the received elastic waves. As a result of the analysis, the defect inside the structure C, the presence or absence of the back cavity, and the distance to the position of the defect are measured.

Based on these analysis results, when there is an abnormality in the elastic wave, the corresponding location (deformed portion) is marked by the marking device 5 . For example, marking is performed by printing "dots" on the relevant portion (deformed portion). The direction of movement of the non-destructive test device 1 (impact test unit 2) may be upward movement, horizontal movement, or upward movement.

<Modification 1 of impact test unit>
FIG. 5 is an enlarged plan cross-sectional view showing Modification 1 of the impact test unit constituting the nondestructive testing apparatus for structures of Embodiment 1. FIG.
The impact test unit 2 of Modification 1 is a unit in which one impact hammer 3 and two receivers 4 are arranged. Furthermore, in the impact test unit 2 of Modification 1, the interval between the two receivers 4 can be freely changed. By changing the distance between the two receiving devices 4 that receive the elastic wave propagated in the structure C by the impact of the impact hammer 3, the thickness and material of the object to be inspected such as the structure C can be changed. It's like In the impact test unit 2 of Modification 1, as shown in FIG. 5, the two parallel receivers 4 are brought closer to each other or moved away from each other.

By adjusting the interval between the receiving devices 4, it is possible to deal with wide and narrow measurement ranges (surfaces) of the concrete structure C. FIG. For example, when widening the measurement range of the concrete structure C, the distance between the receiving devices 4 is widened in order to widen the range for receiving the propagated elastic waves. Conversely, when the measurement range of the concrete structure C is narrow, the distance between the receivers 4 is narrowed because there is no need to widen the range for receiving elastic waves.

<Modification 2 of impact test unit>
FIG. 6 is an enlarged plan cross-sectional view showing Modified Example 2 of the impact test unit constituting the non-destructive testing apparatus for structures of Example 1. FIG.
In the impact test unit 2 of Modification 2, the distance between the two receivers 4 and the impact hammer 3 can be freely changed. The two receiving devices 4 are brought closer to or farther from the impact hammer 3 as required. This is also because the thickness and material of the object to be inspected such as the structure C are variable.

By adjusting the distance between the receiving device 4 and the impact hammer 3, the depth of the deformed portion in the concrete structure C can be dealt with. For example, if the concrete structure C is thin, the time to receive the propagated elastic wave is short, so the interval is narrowed. On the contrary, when the concrete structure C is thick, the time for receiving the elastic wave is long, so the interval is widened.

Each impact test unit 2 can also be attached to the movable support member 7 so as to be variable in angle. In this way, if the impact test unit 2 can individually change the angle with respect to the surface of the concrete structure C, the impact hammer 3 can impact the curved surface of the structure C at an appropriate angle, and the elastic wave can be reliably generated. can be received by the receiving device 4.

<Configuration of non-destructive testing equipment>
FIG. 7 is a schematic plan view showing a non-destructive testing apparatus for structures of Example 2, in which a plurality of impact test units are horizontally arranged so that their positions can be adjusted.
The structural non-destructive testing apparatus 31 of Example 2 is an apparatus provided with a spacing adjustment support member 32 to which each impact test unit 2 is attached so that the spacing between the plurality of impact test units 2 can be adjusted. . For example, as the interval adjusting support member 32, a slide rail that supports the impact test unit 2 via a support 33 can be used. The slide rail may be an extendable member. This is because it facilitates transportation.

The nondestructive testing apparatus 31 of the second embodiment narrows the interval between the impact test units 2 when inspecting the structure C in detail according to the object of the nondestructive testing. Conversely, when inspecting a wide range, the interval between each impact test unit 2 can be widened.

<Configuration of non-destructive testing equipment>
FIG. 8 is a schematic plan view showing a non-destructive testing apparatus for structures according to Embodiment 3, in which a plurality of impact hammers and a plurality of receivers are horizontally arranged so that their positions can be adjusted.
A structure non-destructive testing apparatus 41 of Example 3 includes a device supporting member 42 to which each striking hammer 3 and receiving device 4 are attached so that the intervals between the plurality of striking hammers 3 and receiving devices 4 can be adjusted. It is a device. The impact hammer 3 and the receiving device 4 are supported by the device support member 42 such as a slide rail via a support member 43 .

In the nondestructive testing device 41 of the third embodiment, the distance between the impact hammer 3 and the receiving device 4 is narrowed when inspecting the structure C in detail according to the object of the nondestructive testing. Conversely, when inspecting a wide range, the striking hammer 3 and the receiving device 4 can be arranged with a wider interval.

Further, although not shown, in the structure non-destructive testing device 41 of the third embodiment, the device support member 42 can be replaced with a slide rail and can use an extendable member.

In addition, in the present invention, by unitizing and connecting a plurality of nondestructive testing devices, nondestructive testing can be performed in a wide range at the same time. If the striking hammer 3 can hit the surface of the structure C at an appropriate angle, and the elastic wave can be received by the receiving device 4, and the accuracy of the test can be improved, the above-described embodiment of the invention can be achieved. It is not limited, and various modifications can be made without departing from the gist of the present invention.

INDUSTRIAL APPLICABILITY The present invention is not limited to structures such as railway tunnels, expressways, and buildings, and can be used for non-destructive inspection of metal and synthetic resin structures other than concrete.

REFERENCE SIGNS LIST 1, 31, 41 nondestructive test device 2 impact test unit 3 impact hammer 4 receiving device 5 marking device 7 movable support member 32 interval adjustment support member 33 support device 42 device support member 43 support device C structure (concrete structure)

Claims (4)

A nondestructive testing device (1) for a structure that nondestructively tests a structure (C) using a plurality of impact hammers (3),
a striking hammer (3) for inputting an elastic wave into the structure (C); a receiver (4) for receiving the elastic wave propagated through the structure (C) by the striking of the striking hammer (3); a percussion test unit (2) consisting of
A movable support member (2) to which each impact test unit (2) is movably attached so that the impact hammers (3) of the multiple impact test units (2) are shifted in adjacent rows and arranged at a constant pitch. 7) and
The impact test unit (2) is a triangular arrangement of one impact hammer (3) and two receivers (4), and the two receivers (4) are connected to the structure ( In order to correspond to the wide and narrow measurement range of C), the receiving devices (4) are movably arranged at intervals,
Since the striking hammers (3) and the receiving device (4) are close to each other, the elastic waves propagated within the structure (C) due to the impacts of the striking hammers (3) can be easily received. A non-destructive testing device for structures characterized by: The two receivers (4) are movably arranged at a distance from the impact hammer (3) so as to correspond to the depth of the deformed portion in the structure (C). A non-destructive testing apparatus for structures according to claim 1 , characterized in that: Each impact test unit (2) is variably attached to the movable support member (7) so that the angle of each impact test unit (2) with respect to the surface of the structure (C) can be individually varied. The non-destructive testing device for structures according to claim 1 . A non-destructive testing device (41) for structures that non-destructively tests a structure (C) using a plurality of impact hammers (3),
a striking hammer (3) for inputting an elastic wave into the structure (C);
a receiving device (4) for receiving elastic waves propagated in the structure (C) by the impact of the impact hammer (3);
a device support (42) to which each striking hammer (3) and receiving device (4) are mounted so as to adjust the distance between a plurality of said striking hammers (3) and said receiving devices (4);
Depending on the object of the non-destructive test, when inspecting the structure (C) in detail, the distance between the impact hammer (3) and the receiving device (4) is narrowed, and when inspecting a wide range, the impact hammer A non-destructive testing device for a structure, characterized in that it is arranged so that the distance between (3) and the receiving device (4) can be widened.

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