JP2002267422A - Method and device for crack detection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device which can securely detect a crack slightly developing by a simple means. SOLUTION: A bar code 30 is provided where a body 11 to be measured has a crack 12, and is irradiated with read light 3 from a bar code reader 31 and read. If the bar code 30 breaks or extends to have a change in the width or shape of its symbols and a read error occurs to the bar code reader 31, it is judged that the crack 12 has developed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting an early discovery of the progress of cracks (cracks) occurring in a structure, and more particularly, to cracks and tunnels in buildings such as buildings and bridges. The present invention relates to a crack detection method and device for reliably detecting cracks in civil engineering structures such as roads, rocks that are likely to collapse, and cracks in the ground such as dangerous slopes by simple means.

[0002]

2. Description of the Related Art Conventionally, various methods as shown in FIGS. 5 to 8 have been used to measure a crack 12 of an object 11 to be measured. FIG. 5 shows a method of measuring the width d of the crack 12 by directly applying the vernier caliper 13 to the crack 11 while approaching the workpiece 11 where the crack 12 has occurred, and detecting a change.

[0003] FIG. 6 shows the DUT 1 on both sides of a crack 12.
In this method, two nails 14 are driven at a predetermined interval, and a change in the crack 12 is observed by periodically measuring the interval between the two nails 14. FIG. 7 shows that two anchor bolts 15 are driven into the DUT 11 on both sides of the crack 12 at predetermined intervals, and these anchor bolts 1
Each of the narrow plates 16 with a mark 17 is attached to each of the reference numerals 5 so that the two narrow plates 16 are moved while substantially contacting each other. As shown in FIG. In this method, the crack width d is measured from the interval between the marks 17 provided on the narrow plate 16 to detect a change.

[0004] FIG. 8 shows a three-dimensional type crack measuring device.
The X, Y scale plate 18 and the Z scale plate 24 are attached by bonding or the like. At this time, the X-direction scale 19 of the X, Y scale plate 18, the Y-direction scale plate 20, and the Z-direction scale 2 of the Z scale plate 24.
5 is adjusted to each of the X, Y, and Z axes of the three-dimensional coordinates. A transparent plate 21 and a baseline plate 26 are attached to the DUT 11 on the other side of the crack 12 by bonding or the like. At this time, the Y-direction base line 22 of the transparent plate 21
And the X-direction base line 23 correspond to the X-direction scales 19 and Y, respectively.
Facing the directional scale plate 20 and the base plate 26
The Z-direction base line 27 faces the Z-direction scale 25. Then, a change in the X-axis direction is detected by a shift between the Y-direction base line 22 and the X-direction scale 19, a change in the Y-axis direction is detected by a shift between the X-direction base line 23 and the Y-direction scale plate 20, and the Z-direction base line is detected. 27 and the Z-direction scale 25
Detect changes in the axial direction.

[0005]

The method shown in FIG. 5 is a method of directly measuring a crack width d with a caliper 13 and detecting a change. It cannot be measured in dangerous places.

The method shown in FIGS. 6 and 7 allows not only direct measurement using a ruler or a caliper 13, but also indirect measurement using a telescope, binoculars, photographs, or the like. Used for But nail 1
4. The method of installing the anchor bolt 15, the narrow plate 16 and the like is unstable, and the indirect measurement using a telescope, binoculars, photographs and the like has a problem that the reading method is unstable and the error is large.

The simple three-dimensional type method shown in FIG. 8 is a type in which the X, Y scale plate 18, the transparent plate 21, the Z scale plate 24, and the base plate 26 are directly bonded to the measured object 11 such as concrete. It is difficult to adhere to or peel off, and it is difficult to read the displacement between the transparent plate 21 and the X, Y scale plate 18. In the case of indirect measurement by photographing, the X direction scale 19, Y Direction scale plate 20,
Z direction scale 25, Y direction base line 22, X direction base line 23, Z
X, Y, Z, such as the relationship of the direction base line 27 is not clearly shown
Cannot be obtained accurately.

An object of the present invention is to provide a method and an apparatus capable of reliably detecting a small progress of a crack by simple means.

[0009]

According to the present invention, an object to be measured 11 is provided.
A bar code 30 is provided at a position where the occurrence of cracks 12 is monitored, and a reading light 32 such as a visible light semiconductor laser beam is irradiated from a bar code reader 31 to a bar code 3.
Reads 0.

If the bar code 30 is read, and the bar code 30 is torn or stretched, the width or shape of the symbol of the bar code 30 changes, and a reading error occurs in the bar code reader 31, It is determined that the crack 12 has progressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. In FIG. 1, a barcode 30 is provided at the position of the crack 12 where the crack has already occurred on the DUT 11 or at the position where the crack 12 has not yet occurred but is monitored. The symbol of the barcode 30 is composed of a combination of a narrow bar (thin line), a wide bar (thick line), a narrow space (thin white outline), and a wide space (thick white outline). There are about 100 types of standards around the world depending on what includes symbols, the number of digits, etc., and one of them is selected.

The bar code symbol of the bar code 30 is:
For example, as shown in FIG. 2, it is composed of a start character, data, a check digit, and a stop character.
The number of digits is appropriately adopted according to the amount of information to be stored. In addition, the width of the bar god is 0.125 mm and 0.15 m.
m, 0.19 mm, 0.25 mm, 0.3 mm, 0.4
mm, 0.5 mm, 0.75 mm, and 1.0 mm.
Since the measurement resolution of the barcode reader 31 used in the embodiment of the present invention is 0.15 mm, a displacement of 0.15 mm can be captured when judged with mechanical accuracy.

In order to attach the bar code 30 to the monitoring position of the DUT 11, a mortar, a tile, and the like, which are durable, are not easily stained, and are easily broken together with the cracks 12 of the DUT 11. A method of sticking to the object to be measured 11 by sticking it to porcelain or glass, and a seal that has a durability with a bar code symbol, a weather resistance to heat, oil, moisture, ultraviolet rays, etc. and is hard to be stained. There are a method of attaching to the object 11, a method of directly writing a barcode symbol on the DUT 11, a method of forming the crack 12 without breaking when the crack 12 progresses, and the like. In order to make the barcode 30 easily break as the crack 12 progresses, as shown in FIG. 3A, a cut 29 is formed in at least one side of the outer peripheral edge of the barcode 30. Is also good.

The bar code symbol may have no particular meaning so that it can be determined whether or not the reading by the bar code reader 31 has been performed correctly. The data for specifying the position of the monitoring place and the site information itself such as the type of the crack 12 may be included.

The barcode 30 configured as described above is attached to the monitoring position of the DUT 11. Where the sticking position is round or has irregularities, a barcode 30 made of a flexible material is used. DUT 1
The user goes to one monitoring site every predetermined period, and irradiates a reading light 32 such as a visible light semiconductor laser beam from a bar code reader 31 to read the bar code 30. If a reading error does not occur in the barcode reader 31 and reading is performed normally, this information is stored in a memory in the barcode reader 31.

In reading the barcode 30, if the crack 12 advances, the barcode 30 is broken as shown in FIG. 3A or the barcode 30 is extended as shown in FIG. 3B. For example, when a displacement of 0.15 mm or more occurs in the width or shape of the symbol of the barcode 30,
Since the format is different from the format constructed in advance, the barcode reader 31 cannot read accurate numerical values, characters, symbols, and the like, and a reading error occurs in the barcode reader 31. The information of the reading error is stored in a memory in the barcode reader 31. At this time, crack 12
Is detected whether a reading error occurs irrespective of the vertical, horizontal, or oblique direction.
Note that the barcode reader 31 can read even if a little dirt occurs, even if the line of the barcode 30 can be recognized diagonally without irradiating the reading light 32 at a right angle to the barcode 302.

When a reading error occurs due to the breakage or extension of the bar code 30, or when the bar code 30 becomes dirty or peeled off even after being read, the bar code 30 may be built in the bar code reader 31 at the site or separately. With the provided bar code writer, a new bar code 30 can be printed and attached. In addition, when a new crack 12 is found, a new barcode 30 can be printed and attached to a new monitoring position at the site by a barcode writer.

The data such as whether the bar code reader 31 can read the data at the site or whether a reading error has occurred is returned to the management office and connected to a data processing computer 33 as shown in FIG. This computer 3
3 is an input unit 3 for connecting the barcode reader 31
4. It comprises a control CPU 35, a ROM 36 and a RAM 37 coupled to the CPU 35, a monitor 38, a printer 39, and the like.

In the above configuration, the data in the barcode reader 31 when the barcode reader 31 has read normally is taken into the computer 33, and the data is updated with "no abnormality". It is stored in the RAM 37. When the data in the barcode reader 31 when an error occurs in reading by the barcode reader 31 is taken into the computer 33, "crack progress", "local reissuance of the barcode 30", "secondary consideration" Is updated.

[0020]

According to the first aspect of the present invention, the barcode 30 is provided at the position where the crack 12 is monitored on the DUT 11 and the barcode reader 3 of the barcode 30 is provided.
Since the progress of the crack 12 is detected based on the presence or absence of a reading error due to 1, the progress of the crack can be detected with a simple method at a resolution of a fraction of 1 mm.

According to the second aspect of the present invention, the DUT 1
1 includes a barcode 30 provided at a position where the crack 12 is monitored, and a barcode reader 31 that reads a barcode symbol of the barcode 30 and stores information when the reading is normal and when the reading is error. Therefore, the progress of the crack can be reliably detected with a simple device such as the barcode 30 and the barcode reader 31.

According to the third aspect of the present invention, since the bar code 30 is made of a material which is easily broken by the progress of the crack 12, the shape of the bar code symbol can be obtained in any of vertical, horizontal and diagonal directions. Changes, and the progress of the crack 12 can be reliably detected as a reading error.

According to the fourth aspect of the present invention, since the barcode 30 is made of a material that easily expands due to the progress of the cracks 12, the shape of the barcode symbol changes regardless of whether it extends vertically, horizontally, or diagonally. Thus, the progress of the crack 12 can be reliably detected as a reading error.

According to the fifth aspect of the present invention, since the bar code symbol of the bar code 30 indicates the monitoring position information of the crack 12, the bar code reader 3
1, the data read is stored as it is as the information indicating the monitoring position, and the data can be easily managed.

According to the sixth aspect of the invention, the DUT 1
1, a barcode 30 provided at a position where the crack 12 is monitored, a barcode reader 31 that reads a barcode symbol of the barcode 30 and stores information when the reading is normal and when an error occurs. A computer 33 for updating and storing the data of the code reader 31; managing whether the progress of the click at the monitoring position is normal or abnormal, and updating the data over time; Can be implemented in a unified way.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a crack detection method and device according to the present invention.

FIG. 2 is a front view showing one embodiment of a barcode 30 used in the present invention.

FIG. 3A is a front view of a case where a barcode 30 is broken due to the progress of a crack when a crack is detected according to the present invention,
(B) is a front view when the barcode 30 is extended due to the progress of the crack when the crack is detected according to the present invention.

FIG. 4 is a block diagram showing an example in which a computer 33 is connected to the crack detection device according to the present invention.

FIG. 5 is an explanatory diagram of a conventional measurement method using a caliper 13.

FIG. 6 is an explanatory diagram of a conventional measuring method using a nail 14.

FIG. 7 is an explanatory view of a conventional measuring method using an anchor bolt 15 and a narrow plate 16;

FIG. 8 is an explanatory diagram of a conventional three-dimensional measurement method.

[Explanation of symbols]

11: object to be measured, 12: crack, 13: caliper, 14
... Nail, 15 ... Anchor bolt, 16 ... Narrow plate, 17 ... Mark, 18 ... X and Y scale plate, 19 ... X direction scale, 20 ... Y
Direction scale plate, 21 ... Transparent plate, 22 ... Y direction base line, 23 ...
X direction base line, 24 ... Z scale plate, 25 ... Z direction scale, 26
... Base plate, 27 ... Z direction base line, 29 ... Cut, 30 ...
Bar code, 31 ... Bar code reader, 32 ... Reading light, 33 ... Computer, 34 ... Input unit, 35 ... CP
U, 36: ROM, 37: RAM, 38: Monitor, 3
9 ... Printer.

Claims (6)

[Claims] 1. A bar code 30 is provided at a position where an occurrence of a crack 12 in an object under test 11 is monitored.
A crack detection method, wherein the progress of the crack 12 is detected based on the presence or absence of a reading error by the 0 barcode reader 31. 2. A bar code 30 provided at a position where a crack 12 is monitored on the device under test 11 and a bar code symbol of the bar code 30 are read, and information when the reading is normal and when the reading is error is stored. A crack detection device comprising a barcode reader 31. 3. The crack detecting device according to claim 2, wherein the bar code is made of a material which is easily broken by the progress of the crack. 4. The crack detecting device according to claim 2, wherein the bar code 30 is made of a material that easily expands as the crack 12 advances. 5. The crack detecting device according to claim 2, wherein the bar code symbol of the bar code 30 indicates monitoring position information of the crack 12. 6. A bar code 30 provided at a position where an occurrence of a crack 12 is monitored on the device under test 11 and a bar code symbol of the bar code 30 are read, and information when the reading is normal and when the reading is error is stored. A crack detection device comprising: a barcode reader 31; and a computer 33 for updating and storing data of the barcode reader 31.