JP2003240763A - Nondestructive inspecting method and apparatus for artificial structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nondestructive inspecting method and an apparatus for artificial structure for nondestructively inspecting an artificial structure such as a tunnel inner wall made of a concrete by a simple method without the need for striking the artificial structure with a hammer. <P>SOLUTION: Attention is given to the fact that an ice ball 6 is melted into water at normal temperature with the passage of time. A spherical ice ball 6 is projected by an ice ball projecting device 1 and brought into collision with the surface of the artificial structure such as the tunnel inner wall made of concrete. Its reflected sound is collected by a microphone 2. Frequency analysis is performed on the collected reflected sound by a nondestructive analyzer 3 to nondestructively inspect the strength of the artificial structure such as the tunnel inner wall made of concrete. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for nondestructive inspection of an artificial structure such as an inner wall of a tunnel made of concrete for nondestructive inspection of the strength and internal defects of the artificial structure by impact sound.

[0002]

2. Description of the Related Art Conventionally, an infrared method, a radar method, an ultrasonic method, etc. are known as a method for nondestructively inspecting the strength and internal defects of artificial structures such as concrete. Although these have been studied and announced as alternatives to the tapping method from old times, they have not been widely used because the external meteorological and measurement conditions are severe and the device is expensive.

On the other hand, the hammering method using a hammer is a method that has been used for a long time. Even though the principle is simple, it is still effective, but since it depends on human hearing, it is empirical and sensory. However, there is a problem that the objectivity is poor, and in this respect, Japanese Patent Publication No. 10987/1992 describes an evaluation method by frequency analysis.

Further, the sound striking method using a striking hammer with human power is labor-intensive, and in particular, when the sound of a tunnel inner wall is inspected for sounding, it is necessary for a person to ride on a high stake or to be in a difficult posture. There is.

A tapping method using a hammer for hitting by human power will be described with reference to FIG. In FIG. 3, the impact hammer 12 strikes the surface of the target artificial structure 11 such as the inner wall of a concrete tunnel, and the microphone 1
The reflected sound is collected in 3, and the reflected sound is analyzed by the hammering sound analysis device 14 to detect an internal crack or the like.

Further, Japanese Patent Application Laid-Open No. 7-20097 discloses a method of inspecting concrete products using a hammer hit by a machine and a microphone instead of a hammer hit by a human power.

[0007]

However, in the above-mentioned conventional method, it is necessary to manually hit a man-made structure such as the inner wall of a concrete tunnel with a hammer in order to generate a hitting sound, or even if it is a mechanical type hammer. It is necessary to bring the mechanism into contact with or close to the structure.

When hitting an artificial structure with a hammer by human power, for example, an artificial structure such as concrete in a tunnel requires a crane device for lifting a person, and a cramped posture is forced depending on an angle.

In the case of the mechanical hammer mechanism, it is necessary to properly arrange the hammer and the peripheral mechanism so that the hammer contacts with or comes close to the wall surface.

When the shape of the target artificial structure is not simple, it is not easy to properly install the mechanical hammer and the peripheral mechanism, and it is difficult to work efficiently.

The present invention solves the above-mentioned conventional problems, paying attention to the fact that ice melts into water at room temperature over time, and spherical ice balls are injected onto the surface of an artificial structure. An object of the present invention is to provide a nondestructive inspection method and apparatus for an artificial structure, which non-destructively inspects the strength of the artificial structure by colliding and collecting and analyzing the reflected sound.

[0012]

In order to solve the above problems, the nondestructive inspection method for an artificial structure of the present invention focuses on the fact that ice melts into water at room temperature over time, A feature of the invention is that the strength of the artificial structure is nondestructively inspected by injecting ice balls onto the surface of the artificial structure to collide with them and collecting and analyzing the reflected sound.

With this configuration, the strength of the artificial structure can be efficiently inspected nondestructively even in a place where work is difficult.

In order to solve the above-mentioned problems, a nondestructive inspection apparatus for artificial structures of the present invention is an ice ball injection device for injecting spherical ice balls on the surface of an artificial structure, and an injection by the ice ball injection device. A microphone that collects a reflected sound when the ice ball collides with the artificial structure, and a nondestructive analysis device that analyzes the collected reflected sound and inspects the strength of the artificial structure nondestructively, The feature is that the strength of the structure can be inspected nondestructively.

With this configuration, the strength of the artificial structure can be efficiently inspected nondestructively even in a place where work is difficult.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) A non-destructive inspection apparatus for an artificial structure according to a first embodiment of the present invention is for inspecting an inner wall of an artificial structure. It is intended for artificial structures made of concrete or the like.

FIG. 1 shows the construction of a nondestructive inspection apparatus for an artificial structure according to the first embodiment of the present invention and a state of inspecting the inner wall of the artificial structure using the nondestructive inspection apparatus. is there.

In FIG. 1, the non-destructive inspection apparatus according to the present invention is an ice ball ejecting apparatus 1 for ejecting a spherical ice ball 6 onto the surface (tunnel inner wall 5) of an artificial structure, and ice ejected by the ice ball ejecting apparatus 1. A microphone 2 having directivity for collecting reflected sound when the ball 6 collides with an artificial structure, a nondestructive analysis device 3 for analyzing the collected reflected sound and nondestructively inspecting the strength of the artificial structure, It is movable and is composed of a dolly 4 for fixing an ice ball ejecting device 1, a microphone 2, a nondestructive analysis device 3 and the like.

The ice ball ejecting device 1 has the same structure as a throwing means utilizing spring force, for example, a pitching machine used for batting practice, and throws an ice ball 6 in place of a baseball. It is configured to be possible. The ice ball ejecting device 1 is equipped with a mechanism capable of ejecting the ice balls 6 at different angles, which allows inspection while scanning the wall surface.

The microphone 2 collects the reflected sound in the vicinity of the target when the ice ball 6 emitted by the ice ball emitting device 1 collides with the artificial structure and converts it into a sound electric signal. An array microphone with high directivity is desirable to accurately pick up sound from the target surface. The microphone 2 is configured to move in conjunction with the ice ball ejecting apparatus 1 so that the aim is always the same.

The nondestructive analysis device 3 synchronizes with the ejection of the ice balls 6 from the ice ball ejection device 1 and frequency-analyzes the reflected sound in the vicinity of the target collected by the microphone 2 to analyze internal cracks and internal parts of the artificial structure. Detects the presence of voids.
The configuration is the same as that of performing the analysis by the frequency analysis described in JP-A-7. The dolly 4 is provided with a self-propelled means for moving. Further, a towing vehicle for towing the bogie 4 may be provided without the self-propelled means.

The operation of the nondestructive inspection apparatus for artificial structures according to the first embodiment of the present invention will be described with reference to FIG. In FIG. 1, an ice ball injection device 1 injects a spherical ice ball 6 so as to collide with an inner wall surface 5 of a concrete tunnel which is a target of nondestructive inspection. The impact of the ice balls 6 on the inner wall surface 5 excites the natural vibration of the concrete of the tunnel wall to generate a reflected sound corresponding to the state of the wall surface, and the reflected sound is collected by the microphone 2.

As described above, in the non-destructive inspection apparatus for artificial structures of the present invention, the ice balls 6 ejected by the ice ball ejecting apparatus 1 hit the inner wall surface 5 of the artificial structure to generate a tapping sound, which is generated. The tapped sound is collected by the microphone 2. Ice ball 6
Since it is used for hitting, it is not necessary to use a hammer or the like in the vicinity of the wall surface 5, and it is possible to hit the wall surface 5 even if it is separated from the wall surface 5 to some extent. Also, ice balls 6
Melts into water at room temperature, so there is no need to collect the ice balls 6.

Ice balls 6 collected by the microphone 2
By the frequency analysis of the tapping sound by the nondestructive analysis device 3, it is possible to detect voids and internal cracks in the concrete inner wall. Although FIG. 1 shows an example in which the nondestructive analysis device 3 is used, a human may hear the tapping sound collected by the microphone 2 to determine the state of the concrete inner wall. Compared to the hammer hit, the ice ball 6 hit can give a stable hitting force,
Since it is not necessary for the worker to approach the tunnel wall surface and take a cramped posture, the load on the worker can be greatly reduced.

As described above, according to the first embodiment of the present invention, paying attention to the fact that ice balls melt at room temperature over time to become water, and artificial structures such as concrete inner walls of tunnels are used. It is possible to obtain a non-destructive inspection device capable of non-destructively inspecting the strength of an artificial structure such as an inner wall of a concrete tunnel due to the reflected sound of a spherical ice ball that is ejected and collided with the surface of the. This makes it possible to easily perform nondestructive inspection of the strength of artificial structures such as concrete tunnel inner walls without the need for workers to approach the walls of artificial structures such as concrete tunnel inner walls. is there.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
The configuration of the non-destructive inspection device for an artificial structure according to the above embodiment is further provided with a storage water supply means 7 and an ice making means 8. The stored water supply means 7 stores water and supplies the stored water to the ice making means 8. The stored water supply means 7 is mounted on the carriage 4 together with the ice ball injection device 1, the microphone 2 and the nondestructive analysis device 3 not shown in FIG.
An independent vehicle may be provided with a function as a water truck (not shown).

The ice making means 8 is provided with an ice making tray (not shown) inside to cool the water supplied from the stored water supply means 7,
Generates a spherical ice ball. At this time, the hardness and size of the ice balls can be changed by changing the cooling temperature and the ice making tray (not shown).

An ice making tray (not shown) is a mold in which a plurality of hemispherical molds are arranged facing each other, and a hole for allowing water to enter is formed on one side thereof. It is possible to generate a spherical ice ball by closing this mold, pouring water from the hole opened on one side, then cooling it sufficiently and opening the mold. Send to device 1. The other configuration is similar to that of the first embodiment, and therefore the description is omitted.

The frequency of the sound reflected from the wall surface can be changed by changing the size and hardness of the ice balls. Therefore, it is possible to select the desired frequency band by changing the size and hardness of the ice balls according to the state of the measurement target. That is, to focus on a relatively high frequency, make ice balls small and hard, and conversely, to focus on a relatively low frequency, make ice balls large and soft. Since ice balls require repeated measurement under the same conditions, it is not desirable to change the conditions after setting. In addition, non-destructive analysis device 3
(Not shown) performs necessary frequency analysis according to the size and hardness of the set ice balls.

As described above, according to the second embodiment of the present invention, the size and hardness of the ice balls can be changed according to the frequency of interest, so that the frequency analysis can be performed more efficiently. It becomes possible, and more accurate nondestructive inspection of concrete structures becomes possible.

(Third Embodiment) The nondestructive inspection apparatus for artificial structures according to the third embodiment of the present invention is not shown, but the ice ball ejection apparatus shown in the first embodiment is used. 1 has a structure in which the ejection force of the ice balls can be changed by changing the spring force of the throwing means provided in 1.

An ice ball 6 ejected from the ice ball ejecting device 1
The frequency of the reflected sound after being hit can be changed by freely changing the ejection speed of the.

As described above, according to the third embodiment of the present invention, more effective frequency analysis can be performed by changing the frequency to be focused on similarly to the second embodiment of the present invention. it can.

(Fourth Embodiment) The nondestructive inspection device for artificial structures according to the fourth embodiment of the present invention is not shown, but the ice ball injection shown in the first embodiment is performed. By combining a mechanism provided in the device 1 for ejecting the ice balls 6 by changing the angle and a mechanism for moving the carriage 4 carrying the ice ball ejection device 1, the wall surface of the target artificial structure is combined. It is provided with a wall surface entire surface scanning mechanism that allows the spherical ice balls 6 to be applied to the entire surface.

As described above, according to the fourth embodiment of the present invention, by providing the wall surface whole surface scanning mechanism that allows the spherical ice balls to hit the entire wall surface of the target artificial structure, Non-destructive inspection of the wall surface of all artificial structures is possible.

(Fifth Embodiment) Although not shown, the non-destructive inspection device for artificial structures according to the fifth embodiment of the present invention is used only as a power source for moving the carriage 4. Instead, the ice ball ejection device 1, the microphone 2, and the nondestructive analysis device 3 are configured to be able to supply electric power by using a railway overhead wire.

If the target artificial structure is a concrete wall surface in a tunnel through which a train passes, the nondestructive inspection is usually performed at night after the railway operation is completed.
If the power supply from the overhead line is used not only as a power source for moving the carriage 4 but also as a power source for the ice ball ejecting device 1, the microphone 2, the nondestructive analysis device 3, etc., night power can be effectively used. Therefore, the non-destructive inspection of the tunnel wall surface can be performed at a lower cost. However, it goes without saying that the non-destructive inspection of the tunnel wall surface is limited to the electrified section.

[0039]

INDUSTRIAL APPLICABILITY As described above, the present invention focuses on the fact that an ice ball melts into water at room temperature over time, and a spherical ice ball is formed on the surface of an artificial structure such as an inner wall of a concrete tunnel. By injecting and colliding the sound, analyzing the reflected sound after the collision and performing nondestructive inspection of the strength of the artificial structure such as the concrete tunnel inner wall, the structure of the concrete tunnel inner wall etc. The effect that a nondestructive inspection can be performed is obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a nondestructive inspection device for artificial structures according to a first embodiment of the present invention,

FIG. 2 is a diagram showing a configuration of a nondestructive inspection device for artificial structures according to a second embodiment of the present invention,

FIG. 3 is a diagram showing a configuration of a conventional nondestructive inspection device for an artificial structure using a hammering hammer and a hammering analysis device.

[Explanation of symbols]

1 Ice ball injection device Two microphones 3 Nondestructive analysis device 5 tunnel inner wall 6 spherical ice balls 7 Storage water supply means 8 means of ice making 11 Artificial structures such as tunnel inner walls 12 hammer 13 microphone 14 Sound analysis device

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2G047 AA05 AA10 BA04 BC04 BC07                       CA03 CA07 DB12 DB18 EA12                       EA14 GD02 GJ02 GJ03

Claims (6)

[Claims] 1. A non-destructive inspection of the strength of the artificial structure by injecting a spherical ice ball onto the surface of the artificial structure for collision and collecting and analyzing the reflected sound. Destructive inspection method. 2. An ice ball ejecting device for ejecting a spherical ice ball on the surface of an artificial structure, and a reflected sound when the ice ball ejected by the ice ball ejecting device collides with the artificial structure. An artificial structure comprising a microphone and a non-destructive analysis device for non-destructively inspecting the strength of the artificial structure by analyzing collected reflected sound, and capable of non-destructively inspecting the strength of the artificial structure. Non-destructive inspection equipment for objects. 3. A storage water supply means for storing water and supplying the stored water, and an ice making means for receiving water from the storage water supply means to make ice balls into spherical ice balls, wherein the ice making means comprises the ice balls. The nondestructive inspection device for an artificial structure according to claim 2, wherein the size and the hardness of the ice balls can be varied when making ice. 4. The ice ball ejecting device comprises a throwing means for ejecting the ice ball by utilizing a spring force, and the ejection speed of the ice ball is changed by varying the spring force of the throwing means. The non-destructive inspection device for an artificial structure according to claim 3, wherein 5. A combination of a mechanism provided in the ice ball ejecting device according to claim 2 for ejecting ice balls by changing an angle and a mechanism for moving a dolly equipped with the ice ball ejecting device. The artificial structure according to any one of claims 2 to 5, further comprising a wall surface whole surface scanning mechanism that allows the ice balls to hit the entire wall surface of the target artificial structure. Non-destructive inspection equipment. 6. The ice ball ejection device according to claim 2, as well as the power source for moving the trolley according to claim 5, and the microphone and non-destructive device according to claim 2. The non-destructive inspection device for an artificial structure according to any one of claims 2 to 5, wherein a railway overhead wire is used as a power source of the analysis device.