JPH1164305A - Vibration / vibration receiving device for concrete wall back surface inspection - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an excitation / vibration receiving device for inspecting the presence or absence of a gap on the back surface without making a hole in a concrete wall. SOLUTION: A vibration generating unit 20 for generating an elastic wave by applying a hammer 21 to a wall surface 2A of a concrete wall by an impact spring 22, and an elastic wave in the concrete wall being pressed against the wall surface 2A by a pressing spring 32. And a vibration receiving unit 30 having an accelerometer 31 for converting the hammer 2 into a corresponding electric signal are housed in the chambers 42 and 43 of the housing 40, respectively.
1 and the accelerometer 31 were respectively protruded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating / vibrating device suitable for inspecting the presence or absence of a gap on the back of a concrete wall by using an elastic wave.

[0002]

2. Description of the Related Art In tunnels and other concrete structures, it is often necessary to detect whether there is an air gap behind the concrete wall. For example, a tunnel will be completed by lining work after excavation of the tunnel, but in the case of renewal work of a tunnel that has been completed for decades, lining concrete that may cause collapse of the tunnel You must check for gaps between the steel and the rebar. Conventionally, when inspecting the condition on the back side of a concrete wall for the above-mentioned purpose, a method of making a small hole in the concrete wall and allowing an operator to look into the inside from there to check for a gap is generally adopted.

[0003]

However, according to this conventional method, it is necessary to drill a hole in a concrete wall, which is troublesome, and an operator looks into the rear part of the wall through the hole to check for a gap. Requires skilled intuition and effort. Therefore, there is a problem that it is not easy for everyone, and it takes a very long time and the cost is high. The object of the present invention is therefore to
A vibration / vibration receiving device for non-destructive inspection of the back surface of a concrete wall, which enables anyone to easily check for voids on the back of the concrete wall without having to make a hole in the concrete wall. It is in.

[0004]

A feature of the present invention to solve the above-mentioned problems is a vibration / vibration receiving device used for inspecting the condition of the back surface of various concrete walls using elastic waves. A hammer, a striking spring member for biasing the hammer in a predetermined direction, and an electric signal indicating a timing at which the hammer strikes the back surface of the concrete wall in cooperation with the striking spring member. A vibrating unit for applying a predetermined impact to the surface of a concrete wall having a trigger, an accelerometer, a pressing spring member for pressing the accelerometer to a required state on the surface of the concrete wall, and the acceleration A vibration receiving unit comprising an amplifier for adjusting the level of an output signal from the meter;
The present invention is characterized in that it comprises a single housing for integrally storing the vibration generating unit and the vibration receiving unit.

According to the present invention, in the above configuration, the housing is divided into two chambers that open in the same direction, and one of the chambers houses the vibration unit and the other room houses the vibration receiving unit. Configuration.

According to the present invention, in the above configuration, the vibration generating unit is housed in one of the chambers so that the hammer can jump out of the opening of one of the chambers by the striking spring member. It is proposed that the accelerometer be housed in the other chamber so as to protrude from the opening by the holding spring member.

In the above invention, a vibration unit for hitting a concrete wall surface, and an elastic wave generated in a structure such as a concrete wall by a hit given by the vibration unit and propagating therethrough are captured. And a vibration receiving unit for obtaining a corresponding electric output signal are housed in the same housing, which is convenient for carrying and installing. Also, since the hammer cooperates with the striking spring member to apply a predetermined impact to the concrete wall, the vibration exciter unit applies a greater impact to the concrete wall than an operator manually impacts to the concrete wall. It can be made more uniform, can be used by anyone, and can perform highly accurate measurement without requiring skill.

Further, according to the configuration in which the hammer and the accelerometer are made to project in the same direction from the corresponding openings of the housing, the vibrating unit and the vibration receiving unit can be connected to the concrete simply by putting the opening of the housing on the concrete wall. Since it can be set on a wall, it is convenient and very convenient.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of an embodiment of a vibration and vibration receiving device according to the present invention. The vibration and vibration receiving device 10 shown in FIG. 1 is used as a vibration and vibration receiving device and a vibration receiving device for a tunnel side wall inspection system 1 for inspecting whether there is a gap on the back of a lining concrete wall of a tunnel side wall. I have.

The vibration / vibration receiving device 10 includes a vibration unit 20 for applying a predetermined impact to the wall surface 2A of the lining concrete wall 2, and a lining concrete wall by the impact applied to the wall surface 2A by the vibration unit 20. A vibration receiving unit 30 for receiving a seismic wave (elastic wave) W generated in 2 and outputting an electric output signal E corresponding to the received seismic wave W is integrally housed in a housing 40. .

The housing 40 is made of iron or another suitable rigid metal material, and is a hollow rectangular tube-shaped member having one end opened. The inside of the housing 40 is partitioned into two chambers 42 and 43 by a partition wall 41, and the vibration unit 20 is housed in one chamber 42 and the vibration receiving unit 30 is housed in the other chamber 43. ing.

The vibration unit 20 includes a columnar hammer 21 made of a hard metal material such as steel, and a hammer 21.
And a striking spring 22 for urging the one end face 21A of the slab toward the lining concrete wall 2. In the present embodiment, the hammer 21 is arranged so that the axis of the hammer 21 is parallel to the axis of the one chamber 42, and the plurality of guide projections 25 provided on the inner wall surface of the one chamber 42 causes the hammer 21 to move along its axis. It is guided so that it can move forward and backward in the direction. And a striking spring 22 formed as a coil spring.
Are the other end surface 21B of the hammer 21 and the rear wall surface 42 of the chamber 42.
A. Rear end face 21 of hammer 21
B, the operating rod 2 extends along the axis of the chamber 42.
The operation end 23A of the operation rod 23 projects outside the housing 40 through a through hole 42B formed in the rear wall surface 42A of the chamber 42.

Accordingly, when the operator pulls the operating end 23A of the operating rod 23 by hand and releases his / her hand from the operating end 23A with the striking spring 22 contracted, the hammer 2
1 is an opening 42 of the chamber 42 due to the resilience of the impact spring 22.
Moving forward toward C, the wall 2 of the concrete wall 2
You can hit 1A. In order to extract an electrical signal indicating the timing at which the hammer 21 hits the wall surface 21A, a trigger 24 made of, for example, a piezoelectric element is fixed to the side surface of the hammer 21. The output line 24A connected to the trigger 24 is drawn out of the housing 40 through another through hole 42D formed in the rear wall 42A of the chamber 42,
The trigger signal T output from the trigger 24 is input to the measuring device main body 3 described later.

The vibration receiving unit 30 receives a seismic wave (elastic wave) W generated by the impact given to the concrete wall 2 by the vibration generating unit 20 and receives a corresponding acceleration signal A.
And a pressing spring 32 for pressing the accelerometer 31 against the wall surface 2A of the concrete wall 2.

In this embodiment, the chamber 43 is provided inside the chamber 43.
A cylindrical body 33 fixed to the rear wall surface 43A is provided so as to extend along the axial direction of the chamber 43, and a holding spring 32 formed as a coil spring on a lower end surface 33A of the cylindrical body 33. , An accelerometer 31 is attached. When the housing 40 is not set on the concrete wall 2, the accelerometer 31 attached to the holding spring 32 projects from the opening 43 </ b> B of the chamber 43. By pressing the housing 40 against the concrete wall 2 with the opening 43B facing the wall surface 2A, the vibration receiving surface 31A of the accelerometer 31 protruding from the opening 43B is pressed against the wall surface 2A with an appropriate pressure by the elastic force of the pressing spring 32. It is pressed and brought into the state shown in FIG.

An amplifier 34 having an input electrically connected to the output of the accelerometer 31 is housed in the cylindrical body 33. An acceleration signal A output from the accelerometer 31 is input to the amplifier 34. , Where it attenuates to a predetermined level. An output signal is obtained from the amplifier 34 as an electrical output signal E of the vibration receiving unit 30, and the electrical output signal E is input to the measuring device main body 3 via the output lead L.

The measuring device main body 3 comprises a personal computer 4, a DAT tape recorder 5 for recording an electrical output signal E and a trigger signal T, and a display device 6. A predetermined program is set in the personal computer 4, and the personal computer 4
Then, based on the signal recorded on the DAT tape recorder 5, the reflected wave from the back of the concrete wall is analyzed from the recorded amplitude signal data several times, and the reflection surface is imaged in the amplitude signal data. , It is configured to interpret the situation behind the concrete wall.

In the personal computer 4, the seismic wave generated by the shock applied to the concrete wall 2 by the vibration unit 20 is analyzed in accordance with the set program. It is determined whether or not a gap exists, and the determination result is displayed on the display device 6. Since this type of program itself is publicly known, a detailed description of the processing of the electrical output signal E and the trigger signal T is omitted here.

Here, the above description of the configuration of the measuring device main body 3 is an example, and a program for determining the presence or absence of a gap on the back surface of the concrete wall 2 based on another known principle is set in the personal computer 4. Needless to say, it may be.

Since the vibrating / receiving unit 10 used in combination with the measuring apparatus main body 3 is configured as described above, the inspector connects the vibrating / vibrating unit 10 and the measuring apparatus main body 3 as described above. Electrically connected, concrete wall 2
At the place where the inspection is desired, the housing 40 is set on the concrete wall 2 such that the openings 42C and 43B are brought into contact with the wall surface 2A, and the operating end 23A of the operating rod 23 is pulled by hand and separated from the end surface of the hammer 21. 21A can be nailed to the wall surface 2A. In this case, if the length of pulling out the operation rod 23 is determined in advance, the impact strength given to the concrete wall 2 can always be kept at a constant level, and high-precision measurement can be expected regardless of who operates the concrete wall 2. be able to.

A seismic wave (elastic wave) W generated by hitting the concrete wall 2 with the hammer 21 has a gap M on the back surface of the concrete wall 2 (the case shown in FIG. 1).
A difference is caused between the frequency in the case where it is not and the case where it is not. The seismic wave W is converted into a corresponding acceleration signal A by an accelerometer 43 pressed against the wall surface 2A by the holding spring 32, and is extracted as an electrical output signal E via the amplifier. The trigger 24 outputs a trigger signal T indicating the timing at which the hammer 21 hits the wall surface 2A. The trigger signal T and the electrical output signal E are input to the measuring device main body 3, where it is determined whether there is a gap on the back of the concrete wall 2 as described above, and the result is displayed on the display device 6. Is displayed.

The vibrating / vibrating device 10 has the vibrating unit 20 and the vibrating unit 30 integrated as described above.
Easy on-site handling. In the embodiment shown in FIG. 1, each opening 4 of the chambers 43 and 42 for storing each unit is provided.
2C and 43B are arranged side by side in the same direction.
The accelerometer 31 can be set on the wall surface 2A and the hammer 21 can strike the wall surface 2A simply by applying the housing 40 to the wall surface 2A. Therefore, the worker who carries out the inspection carries the measuring device main body 3 by hanging it on the shoulder or the like, holds the vibration / vibration receiving device 10 in his hand, and presses the vibrating / vibrating device 10 to an appropriate portion of the wall surface 2A of the concrete wall 2 as described above. By simply pulling and releasing the operating rod 23 as described above, it is possible to easily check whether or not there is a gap on the back of the concrete wall 2 from the display contents on the display device 6 of the measuring device main body 3 without skill. can do.

In this case, the hammer 2 of the vibrating unit 20
1 is configured to be hit against the wall surface 2A by the spring force of the striking spring 22, so that it is possible to easily apply a constant striking force to the wall surface 2A by adjusting the pulling length of the operating rod 23. Therefore, as compared with a case where the wall is hit with a hammer held in a hand, the hitting level can be easily made constant, so that an accurate inspection can be performed.

The effects of the present invention are as follows. (1) Since the vibration generating unit and the vibration receiving unit are housed in a single housing, it is convenient to carry and excellent in usability. (2) Since the vibrating unit has a configuration in which a hammer is hit against a concrete wall, which is an object to be inspected, using a spring force, the impact force can be made constant, which contributes to an improvement in inspection accuracy. (3) In the configuration in which the accelerometer and the hammer project in the same direction from the juxtaposed openings, the setting of the vibrating unit and the receiving unit can be performed easily and simultaneously. It can be significantly improved. (4) As a result, anyone can easily perform a highly accurate inspection in a short time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of an embodiment of a vibration and vibration receiving device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tunnel side wall inspection system 2 Lining concrete 2A wall surface 10 Vibration / vibration receiving device 20 Vibration unit 21 Hammer 21A One end surface 22 Impact spring 23 Operating rod 23A Operation end 24 Trigger 30 Vibration receiving unit 31 Accelerometer 32 Holding spring 34 Amplifier 42, 43 rooms 42C, 43B opening A acceleration signal E electrical output signal T trigger signal W seismic wave (elastic wave)

Claims (3)

[Claims] An exciter / vibrator for inspecting the condition of the back surface of various concrete walls using elastic waves, comprising: a hammer; and a blow for urging the hammer with a spring in a predetermined direction. A predetermined impact on the surface of the concrete wall, comprising a spring member and a trigger for extracting an electrical signal indicating the timing at which the hammer hit the back surface of the concrete wall in cooperation with the impact spring member. A vibrating unit for applying, an accelerometer, a pressing spring member for pressing the accelerometer on a concrete wall surface in a required state, and an amplifier for adjusting a level of an output signal from the accelerometer A concrete wall back condition comprising: a vibration receiving unit comprising: and a single housing for integrally storing the vibration generating unit and the vibration receiving unit. Vibration / vibration device for inspection. 2. The housing is divided into two chambers that open in the same direction, and one of the chambers houses the vibrating unit and the other room houses the vibration receiving unit. Exciter / vibrator for inspecting the condition of the back of concrete wall as described in 1. 3. The vibrating unit is housed in the one chamber so that the hammer can be protruded from the opening of the one chamber by the striking spring member, and the vibration receiving unit is provided in the other chamber. 3. The vibration / vibration receiving device for inspecting the condition of the back of a concrete wall according to claim 2, wherein the accelerometer is housed in the other chamber so as to protrude from the opening by the pressing spring member.