WO2016006049A1 - Concrete structure crack survey method and crack survey system - Google Patents

Abstract

To provide a concrete structure crack survey method capable of accurately surveying a crack state even if corner chipping occurs at a crack location as a result of drilling. A concrete structure crack survey method (SA) includes a first boring step (S1) in which a hole of a survey-subject depth is bored in a concrete structure, injection steps (S2, S3) for injecting a liquid material having a specific color upon curing into the hole bored in the first boring step, a second boring step (S4) for reboring a hole having a larger hole diameter than that of the hole into which the liquid material was injected in the injection step after the liquid material has been cured, and detection steps (S5-S7) for inserting an imaging device into the hole bored in the second boring step and detecting cracking by detecting the specific color.

Description

Method and system for investigating cracks in concrete structures

The present invention relates to a crack investigation method and a crack investigation system for a concrete structure for investigating the state of cracks generated inside the concrete.

Conventionally, the investigation of cracks in concrete structures such as road bridge decks has been carried out by visually inspecting the concrete surface or measuring the size of cracks using an optical device equipped with a magnifying lens with a scale. It has been broken.
Furthermore, in recent years, in order to grasp the cause of deterioration of concrete structures, the state of deterioration, etc., there are increasing cases of investigating cracks inside concrete structures.

As a method for investigating the cracks in the concrete structure, a method is generally used in which the concrete structure is perforated and the interior is imaged and investigated.
For example, a researcher drills a concrete structure with a vibration drill. The investigator then inserts a bar-shaped scanner into the hole and analyzes the image obtained by scanning to investigate cracks. Alternatively, the investigator inserts an industrial endoscope inside the hole and confirms the state of cracking (see, for example, Patent Document 1, Non-Patent Documents 1 and 2).

Further, as a method for investigating cracks in a concrete structure, a method for observing a microscopic cross section of concrete using a fluorescent epoxy resin impregnation method has been proposed (for example, see Non-Patent Document 3).
The technique using this fluorescent epoxy resin impregnation method is to inject and cure an epoxy resin with a fluorescent dye added to a core sample collected from a concrete structure in a low vacuum state and irradiate the core cut surface with ultraviolet rays. The evaluation is made by visualizing fine cracks with a fluorescent color.

JP-A-8-29413

The above-mentioned method of observing the inside of a concrete structure with an endoscope or the like performs drilling with a vibration drill, so even if cleaning is performed at the time of drilling with air cleaning, water cleaning, etc., the chips that have entered fine cracks are removed. It cannot be removed reliably. For this reason, in this method, the width of the crack is determined to be smaller than the actual width at a fine crack portion where the chip is clogged.

Also, in this method, the drilling is performed by vibrating the concrete with the vibration drill, so that a corner chip occurs at the position of the crack inside the concrete facing the position where the drill penetrates. For this reason, the crack width is determined to be larger than the actual width at the portion where the corner chip is generated.

In addition, when using a drill that uses a diamond bit to drill at high speed while flowing fresh water, clogging of fine cracks can be suppressed. However, even when such a drill is used, it is impossible to prevent a phenomenon in which a small corner chip occurs at a cracked portion.
As described above, the conventional method of drilling a concrete structure with a vibration drill and observing the interior with an endoscope or the like has a problem that the actual crack width cannot be accurately investigated.

Further, in the method using the fluorescent epoxy resin impregnation method described above, a core sample must be collected from a concrete structure. In other words, since this method is aimed at investigating cracks rather than maintaining the current state of concrete structures, it destroys a concrete structure that opens a large-diameter hole (for example, a diameter of 50 mm or more) to the concrete structure. This is a survey method.
In this way, the conventional method of investigating cracks by the fluorescent epoxy resin impregnation method using the core sample is not a microdestructive inspection like the conventional investigation method of endoscopes, but a destructive inspection. When repairing an object, there is a problem that it takes time and cost.

The present invention has been made in view of such problems, and on the premise of investigating cracks by microfracture by drill drilling, even when corner cracks occur at the cracks, the state of cracks is accurately investigated. It is an object of the present invention to provide a crack investigation method and a crack investigation system for a concrete structure that can be performed.

In order to solve the above-mentioned problems, the method for investigating cracks in a concrete structure according to the present invention is as follows.

In other words, the method for investigating cracks in a concrete structure includes a first drilling step of drilling a hole having a depth to be investigated in the concrete structure with a predetermined hole diameter by a drilling machine, and the first drilling step. A press-fitting process for press-fitting a liquid member having a specific color at the time of curing, and a hole larger than the hole diameter after curing of the liquid member with respect to the hole into which the liquid member is press-fitted in the press-fitting process. A second drilling step for drilling a hole of the depth to be investigated with a diameter, and an image pickup device is inserted into the hole drilled in the second drilling step, and the crack is detected by detecting the specific color And a detection step.

According to such a procedure, the method for investigating cracks in a concrete structure opens a hole for investigating cracks in the first drilling step. And this crack investigation method hardens | cures with progress of time at a press-fit process, and press-fits the liquid member which has a specific color at the time of hardening. The specific color is different from the color of the concrete structure to be investigated.
As a result, the liquid member is filled in the cracked portion and, if the crack has a corner chip, along with the drilled hole.
And this crack investigation method is a hole diameter larger than the hole diameter (for example, about 2 mm larger) after hardening of a liquid member with respect to the hole into which the liquid member was press-fitted in the press-fitting process in the second drilling step. Drill a hole at the depth to be investigated.

In this way, by re-drilling with a larger hole diameter, the corner chipped portion generated in the first drilling process is cut. Note that, in the second drilling step, since the liquid member press-fitted in the press-fitting step is hardened, no cracked corners due to drilling occur. Therefore, the surface of the hole drilled in the second drilling step is exposed in a state where the liquid member is cured at a cracked portion without a corner chip, and the size at the time of occurrence of the crack is accurately set on the inner surface of the hole. It will appear.

In the crack investigation method, in the detection process, an imaging device such as an endoscope is inserted into the hole drilled in the second drilling process, and a specific color different from the color of the concrete structure to be investigated is detected. To detect cracks.
As a result, this crack investigation method can accurately investigate the occurrence of cracks by imaging the holes drilled in the second drilling step.

The present invention has the following excellent effects.
According to the present invention, even when corner breakage occurs in the cracked part due to microfracture by drilling, after the liquid member is press-fitted and hardened, by drilling with a hole diameter larger than the previously drilled hole diameter, The chipped corners can be removed, and the cracks can be accurately exposed on the surface inside the hole. Thereby, this invention can investigate correctly the crack state inside a concrete structure.
Further, according to the present invention, by using a liquid member having a specific color at the time of curing, a crack can be recognized as a specific color from an image obtained by imaging the inside of the hole, and the presence or absence of a crack is accurately recognized by color. can do.

It is a flowchart which shows an example of the procedure of the crack investigation method of the concrete structure which concerns on this invention. It is a system configuration figure showing the composition of the crack investigation system of the concrete structure concerning the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the state which mounted | worn with various tools in the tool mounting part of the crack investigation system of the concrete structure which concerns on this invention, Comprising: (a) is sectional drawing which shows the state which mounted | worn the drilling machine, (b) is a press-fit apparatus. FIG. 4 is a cross-sectional view showing a state where the (syringe) is mounted, FIG. 3C is a cross-sectional view showing a state where the imaging device is mounted, and FIG. It is a rear view of the perforation direction showing a state where the tool is fixed to the tool mounting portion, (a) is a diagram showing a state when the tool is inserted, (b) is a diagram showing a state where the tool is fixed. It is explanatory drawing explaining an example of the procedure of the drilling | boring in the crack investigation method of the concrete structure which concerns on this invention with (a)-(f). It is a figure for demonstrating the corner chip | corner which generate | occur | produces by drill drilling, Comprising: (a) is sectional drawing which shows the state which the crack generate | occur | produced in the concrete structure, (b) shows the state which drilled the concrete structure. Sectional drawing, (c) is an enlarged view showing an enlarged corner missing portion of (b). It is a figure for demonstrating the method of inject | pouring a liquid member into the hole drilled. It is a figure which shows typically the 1st drilling process, press-fit process, and 2nd drilling process in the crack investigation method of the concrete structure which concerns on this invention, Comprising: (a) shows the state after a drilling (1st drilling process). FIG. 5B is a diagram showing a state after a liquid member (epoxy resin) is press-fitted into the hole (press-fitting step), and FIG. 5C is a diagram showing a state after re-piercing (second punching step). It is explanatory drawing for demonstrating the observation process included in the detection process in the crack investigation method of the concrete structure which concerns on this invention, Comprising: (a) is a figure which shows an observation process typically, (b) is an observation process. The figure which shows an example of the imaging device to be used, (c) is a figure which shows an example of the image imaged with the imaging device. It is sectional drawing which shows the internal structure of an endoscope front-end | tip part. It is explanatory drawing for demonstrating the measurement process included in the detection process in the crack investigation method of the concrete structure which concerns on this invention, Comprising: (a) is a figure which shows a measurement process typically, (b) is a measurement process. The figure which shows an example of the imaging device to be used, (c) is a figure which shows an example of the stereo image imaged with the imaging device. It is explanatory drawing for demonstrating the method of calculating the position of the point designated by the stereo image. It is a figure which shows the example of the other imaging device used at the detection process in the crack investigation method of the concrete structure which concerns on this invention. It is a figure which shows the holding mechanism which hold | maintains several tools, Comprising: (a) is a figure which shows the example arrange | positioned so that the center axis of the 1st tool may correspond to the center axis of a hole, (b) is two It is a figure which shows the example which moved and arrange | positioned the center axis | shaft of the eye tool so that it might correspond with the center axis | shaft of a hole.

Hereinafter, embodiments of the present invention will be described.
[Outline of crack investigation method for concrete structures]
The method for investigating cracks in a concrete structure according to the present invention is a micro-destructive inspection using drill drilling, in which a concrete structure to be investigated is drilled with a drill (first drilling step), and the inside of the hole is specified at the time of hardening. A liquid member having a color is press-fitted (press-fitting process) and cured. And after hardening of a liquid member, this crack investigation method is again drilled in the same position by enlarging a hole diameter (second drilling step). By increasing the diameter of the hole, the cracked corner missing portion generated by the previous drilling is scraped off.
Thereafter, in the crack investigation method, an image pickup device is inserted into the hole, and a crack imaged in a specific color is detected to investigate the state of the crack (detection step).
Hereinafter, a crack investigation method for a concrete structure of the present invention (hereinafter referred to as a crack investigation method) will be described in detail with reference to the drawings.

[Details of crack investigation method for concrete structures]
With reference to FIG. 1, the 1st drilling process of the crack investigation method which concerns on embodiment of this invention, a press injection process, a 2nd drilling process, and a detection process are demonstrated one by one.
The crack investigation method according to the embodiment of the present invention can be realized by, for example, a concrete structure crack investigation system (hereinafter referred to as a crack investigation system) S as shown in FIG.

The individual configuration and processing of the crack investigation system S will be described in detail in the description of each process, but is as follows.
The crack investigation system S includes a drilling machine 13 for drilling in a concrete structure Co, a syringe (pressing apparatus) 20 for press-fitting a liquid member having a specific color into a hole drilled by the drilling machine 13, and a drilling machine. And an imaging device 40 that images the inside of the hole and is configured to be detachably mounted on the tool mounting portion 18 that moves along the guide 12a of the support column 12.
In this crack inspection system S, a concrete structure Co is first drilled by a small-diameter bit 16 and then a liquid member is press-fitted into the hole by a syringe 20. Then, after the liquid member is hardened, the crack investigation system S re-perforates a hole having the same central axis as the small-diameter bit 16 with the small-diameter bit 16b having a larger hole diameter than the small-diameter bit 16.

And the crack investigation system S inserts the imaging device 40 into the re-drilled hole, and images the state of the crack inside the hole. The punching machine 13, the syringe 20, and the imaging device 40 are detachably attached to the tool mounting portion 18 by means of attachment means (here, key structure and fixing screw) via tool fixing tools (insertion assisting tools) 19, 29, and 49. It is configured to be. The tool fixtures 19, 29, and 49 are formed in shapes that can hold the tools (the punching machine 13, the syringe 20, and the imaging device 40), and can be supported in common by the tool mounting unit 18. It is configured.
The tool mounting portion 18 includes a sliding portion 18a that moves along the guide 12a, a holder portion 18b that is formed on the sliding portion 18a and that holds the tool fixtures 19, 29, and 49, and the holder portion 18b. A key groove 18c and a fixing screw 18d for fixing the tool fixtures 19, 29, 49 to the holder portion 18b are provided.
Hereinafter, each step will be described in detail mainly with reference to FIG.

[First drilling step]
As shown in FIG. 1, first, the crack investigation method SA uses a drilling machine (drill) 13 to investigate a concrete structure such as a road bridge deck to be examined for cracks with a predetermined hole diameter. Is drilled (step S1).

The drilling machine 13 can use, for example, a general drill that uses a small-diameter diamond bit and drills at high speed while flowing fresh water. Here, the drilling machine 13 is used by holding the diamond bit on the tool fixture 19 and mounting it on the tool mounting portion 18 as shown in the figure. The tool fixture 19 includes a holding main body 19a for holding the punching machine 13, and a key 19b formed on one end side of the holding main body 19a. Further, the hole diameter by the punch 13 in the first drilling step is, for example, about 4 mm to 25 mm.
In addition, when a reinforcing bar exists in the concrete structure, it is needless to say that the crack investigation method SA searches for the reinforcing bar in advance with a reinforcing bar probe before the step S1 and drills to avoid the reinforcing bar part. .

Here, with reference to FIG. 5, the procedure of drilling in the crack investigation method SA will be described. Note that this drilling procedure is an example, and general drilling may be performed.
As shown in FIG. 5A, in this drilling procedure, first, the base 10 is attached to the wall surface of the concrete structure Co. Here, an example is shown in which a vacuum pad is used as the base 10 and the base 10 is attached to the wall surface by vacuum suction with the vacuum pump 11. Of course, when the vacuum pad cannot be attached, the base 10 may be fixed with an anchor bolt.

Then, as shown in FIG. 5 (b), the drilling procedure is performed by holding the drilling machine 13 on the tool fixture 19 and mounting it on the tool mounting part 18, and the guide of the column 12 installed on the base 10 by the drilling machine 13. It is attached so that it can move linearly along 12a. When the tool fixture 19 is attached to the tool attachment portion 18, as shown in FIGS. 4A and 4B, the key 19b of the tool fixture 19 is engaged with the key groove 18c, as shown in FIG. By fixing with the fixing screw 18d, the drilling machine 13 held by the tool fixing tool 19 is mounted on the tool mounting portion 18.
Then, as shown in FIG. 5C, in the drilling procedure, the centering rod 14 is attached to the punching machine 13, and the tip thereof is set to the position of the marking position T previously attached to the position of the hole to be investigated.
Further, as shown in FIG. 5D, in the drilling procedure, a right-angle jig 15 for holding the drilling angle vertically is attached.

Thereafter, as shown in FIG. 5 (e), the drilling procedure is performed by removing the centering rod 14 and attaching a small-diameter bit (diamond bit) 16. At this time, although not shown, the inside of the hole is always cleaned. Thereby, clogging of cracks can be prevented.

Then, as shown in FIG. 5 (f), in the drilling procedure, the rod 17 is appropriately added according to the drilling depth, and the small-diameter bit 16 is extended to drill to a desired depth.
Thus, the crack investigation method SA drills a small-diameter hole for investigating cracks by drilling as the first drilling step.

Here, with reference to FIG. 6, the state inside the concrete structure in a 1st drilling process is demonstrated.
As shown in FIG. 6A, it is assumed that cracks Cr are generated inside the concrete structure Co.
In this state, as shown in FIG. 6B, in the crack investigation method, in the first drilling step, the drilling machine 13 drills to the depth of the crack investigation target (for example, 1 cm to 1000 cm).
At this time, in the region A where the hole H opened by the punching machine 13 and the crack Cr intersect, corner breakage occurs at the cracked portion.

FIG. 6C is an enlarged view of the region A in FIG. As shown in FIG. 6C, when the inside of the hole H is observed in a state where the corner chip B is generated, a crack larger than an actual crack before the hole H is opened by the drilling machine 13 is observed. Become. For example, if the hole diameter is about 4 mm to 25 mm, corner cracks of about 0.05 mm to 1.0 mm occur at most from the actual end of the crack.
In the crack investigation method according to the present invention, corner chipping in the first drilling step is allowed. The reason for this is to remove corner defects in the following steps.
Returning to FIG. 1, the description of the procedure of the crack investigation method SA will be continued.

[Press-fit process]
After step S1, the crack investigation method SA press-fits a synthetic resin (here, methyl methacrylate resin) that is an organic injection material mixed with a fluorescent dye into the hole drilled in the first drilling step (step S1). S2). The tool fixture 19 holding the punch 13 is removed from the tool mounting portion 18, and the tool fixture 29 holding the syringe 20 is mounted on the tool mounting portion 18, so that the synthetic resin is used using the support 12. It is comprised here so that it can press-fit. The organic injection material is mixed with a curing agent just before press-fitting.

Thus, the methyl methacrylate resin, which is a liquid member, is press-fitted into the hole drilled in the first drilling step, so that not only the drilled hole but also the inside of the crack including the corner missing portion is methyl methacrylate resin. Penetrates and fills.
Here, by mixing a fluorescent dye into the methyl methacrylate resin, it is possible to inspect the cracked state with a fluorescent color different from the color of the concrete structure to be investigated. For example, by using an orange color (light wavelength of 590 to 610 nm) as a color different from the color of the concrete structure, it is possible to make it easier to visually recognize cracks in comparison with the color of concrete.
In this press-fitting process, it is desirable to perform press-fitting at a pressure of about 0.1 MPa in order to prevent damage inside the concrete structure.

This press-fitting process can be performed by a general press obtaining method. For example, as shown in FIG. 7, a needle (blunt needle) 21 is attached to a syringe (press-fit device) 20, and methyl methacrylate resin E, which is a liquid member, is placed inside the syringe 20. The methyl methacrylate resin E is mixed with a curing agent immediately before being put into the syringe 20.
Here, as shown in FIG. 2, the tool 20 is held by the tool fixture 29 and mounted on the tool mounting portion 18. That is, by engaging the key 29b formed at one end of the tool fixture 29 with the key groove 18c of the tool mounting portion 18 and fixing the holding main body portion 29a holding the syringe 20 with the fixing screw 18d, the syringe 20 Is mounted on the tool mounting portion 18. Then, the methyl methacrylate resin E, which is a liquid member, is placed inside the syringe 20 attached to the tool attachment portion 18. The methyl methacrylate resin E is mixed with a curing agent immediately before being put into the syringe 20.

Then, the hole H drilled in the first drilling step is covered with the sealing plug 22, and then the needle 21 is inserted into the sealing plug 22, and methyl methacrylate resin E is press-fitted. The sealing plug 22 may be a rubber plug such as a natural rubber plug, a synthetic rubber plug, a silicon rubber plug, or a fluorine rubber plug, a Teflon plug, a uni-stopper plug (silicon + Teflon powder bonding plug), or the like. it can. The sealing plug 22 may not be used depending on the viscosity of the liquid member to be press-fitted.
In this press-fitting step, for example, in the drilling procedure described in FIG. 5, after FIG. 5 (f), the fixing screw 18d abutting on the tool fixture 19 holding the drilling machine 13 is removed, and the key 19b is pressed. By removing from the keyway 18c, the tool mounting part 18 is removed from the tool mounting part 18, and the tool fixing tool 29 holding the syringe 20 is mounted on the holder part 18b instead. Then, a synthetic resin (methyl methacrylate resin E) is press-fitted from the attached syringe 20.
After this press-fitting process, curing curing according to the time required for curing the press-fitted synthetic resin is performed (step S3).

[Second drilling step]
After the methyl methacrylate resin is cured in step S3, the crack investigation method SA again drills a hole having a depth to be investigated with a hole diameter larger than the hole diameter in the first drilling step (step S1) (step S4). .
At this time, the center axis of the hole to be re-drilled is matched with the center axis of the hole opened in the first drilling step.
The drilling in the second drilling step can be performed in the same manner as the drilling in the first drilling step described with reference to FIG. That is, in the second drilling process, the small-diameter bit 16 (16b: see FIG. 2) having a different hole diameter is attached to the drilling machine 13 used in the first drilling process, and the column 12 installed at the same position as the first drilling process. By moving the drilling machine 13 along the guide 12a, it is possible to drill a hole having the same central axis as the hole drilled in the first drilling process. The punching machine 13 is mounted on the tool mounting portion 18 by the tool fixture 19 as described above.

In addition, the hole diameter of the drilling in the second drilling process may be a size that scrapes off the corner missing portion generated in the first drilling process. For example, as described above, if the hole diameter is about 4 mm to 25 mm, a corner chip of about 0.05 mm to 1.0 mm is generated even if it is large. Re-drilling is performed with a large hole diameter in the range of 0 mm, preferably in the range of 2.0 mm to 4.0 mm.

Here, with reference to FIG. 8, the state inside the concrete structure from the first drilling process to the second drilling process will be described. 8A, 8 </ b> B, and 8 </ b> C show a cross-sectional view in the drilling direction of the concrete structure on the left side, and a cross-sectional view perpendicular to the drilling direction on the right side.

As shown to Fig.8 (a), the corner chip B has generate | occur | produced in the location where the drilled hole H and the crack Cr cross | intersect inside the concrete structure Co after a 1st drilling process.
And as shown in FIG.8 (b), the crack investigation method press-fits the methyl methacrylate resin E which mixed the fluorescent dye in the hole H in the press-fit process. Since this methyl methacrylate resin E is a liquid member, it penetrates into the cracked Cr by being press-fitted.

And as shown in FIG.8 (c), a crack investigation method re-drills with a hole diameter larger than the hole diameter drilled by 1st drilling in a 2nd drilling process. As a result, the corner chip B existing in the hole H shown in FIG. 8A is scraped off as a region inside the hole H ₂ shown in FIG. 8C, and the width of the crack Cr is accurately set in the hole H _2. Will appear on the inside surface.
Returning to FIG. 1, the description of the procedure of the crack investigation method SA will be continued.

[Detection process (observation process)]
After step S4, the crack investigation method SA inserts an imaging device equipped with a direct-view camera into the hole drilled in the second drilling step, and an operator (inspector) selects a specific color (here) from the captured image. Then, the presence or absence of cracks is observed by detecting the fluorescent color (step S5).
As shown in FIG. 3, the endoscope 40 as an imaging device used here is held by a tool fixture 49 and attached to the tool attachment unit 18. The tool fixture 49 includes a main body holding portion 49a that abuts and holds the outer periphery of the tube of the endoscope 40, a key 49b that protrudes outward from the rear side of the main body holding portion 49a, and the key An engaging portion 49c formed in a concave shape toward the front side on the inner peripheral side of 49b, and a positioning holder 49d that engages with the engaging portion 49c and supports the endoscope 40 are provided. . And the engaging part 49c has a recessed space and an internal thread part (not shown) here. The positioning holder 49d has an insertion hole through which the endoscope 40 can be inserted at the center, includes an elastic member (fixed rubber) provided on the distal end side, and a washer, and is provided in the concave space of the engaging portion 49c. The endoscope 40 is supported by being inserted and screwed into the female screw portion. That is, the positioning holder 49d can be screwed into the female screw portion to deform the tip elastic member so as to spread in a single-handed direction, and fix the inserted endoscope 40. At this time, when inserting the endoscope, the operator measures the depth from the surface of the concrete structure to the position where the crack is generated, based on the inserted depth (insertion depth). It is good to do.

In this observation step, for example, an endoscope 40 that includes an imaging unit that captures an image for direct viewing at the tip can be used as the imaging device. In this observation step, the endoscope cable is sequentially inserted into the hole and picked up to display an image including a crack inside the hole on the screen of a display device (not shown).

Here, the detection step (observation step) will be described in more detail with reference to FIG.
As shown in FIG. 9A, in the observation process, an endoscope 40 and a display device 30 that displays an image captured by the endoscope 40 are used.
That is, in the crack investigation method, as shown in FIG. 9A, the inside of the hole drilled in the concrete structure Co is imaged with the endoscope 40. An image captured by the endoscope 40 is transmitted to the display device 30 via a cable and displayed on the screen of the display device 30.

Here, as shown in FIG. 9B, the endoscope 40 is provided with an optical adapter Dv that captures an image for direct viewing (forward direction) at the distal end.
The optical adapter Dv includes a camera C and a light emitting unit L.

Here, the structure of the optical adapter Dv of the endoscope 40 will be further described with reference to FIG.
The camera C captures an image in the direct viewing direction. The camera C includes an objective lens group 41, an imaging device 42, and an imaging unit 43. The camera C captures an image through an observation window 44, and displays the captured image signal through a signal line 45 on the display device 30 ( Output to FIG.

The objective lens group 41 is a lens that guides light incident from the observation window 44 to the image sensor 42, and may be a single lens or a combined lens in which a plurality of lenses are combined. .
The image sensor 42 converts incident light such as a CCD (Charge Coupled Device) into an image signal (electric signal).
The image pickup unit 43 drives and controls the image pickup element 42 to pick up an image, and is a general circuit board or the like. The imaging unit 43 outputs an image signal captured by the imaging element 42 to the signal line 45.

Note that when the inside of the hole is imaged with a wider viewing angle (field angle), the objective lens group 41 may be a wide-angle lens. Further, when the inside of the hole is imaged widely, the objective lens group 41 may be a fish-eye lens (for example, an angle of view of about 180 to 220 degrees). In that case, the camera C may be configured by omitting the observation window 44 and projecting the fisheye lens from the distal end of the endoscope 40.

The light emitting unit L emits light for the camera C to image the inside of the hole. Here, the light emitting unit L emits light from the light guide 47 in which a plurality of optical fibers 47 a are bundled through the illumination window 46. An LED may be used for the light emitting portion L. The light emitted from the light emitting portion L uses ultraviolet rays to cause the methyl methacrylate resin inserted in the cracked Cr to emit light.
The display device 30 displays an image captured by the endoscope 40. The display device 30 includes light emitting means (not shown) in order to emit light (in this case, ultraviolet rays) from the light emitting portion L.
Returning to FIG. 9, the description will be continued.

As described above, the endoscope 40 includes the camera C that captures an image and the light emitting unit L that emits ultraviolet light at the distal end portion, so that a cracked portion inside the hole is formed as illustrated in FIG. Can be captured with a fluorescent color, and a captured image F obtained by capturing the inside of the hole can be displayed on the display device 30.

Thus, the operator can easily confirm the presence or absence of cracks by visually recognizing the captured image F displayed on the display device 30. In addition, when an operator inserts the endoscope 40, from the surface of the concrete structure Co to the position where the crack is generated by measuring the insertion depth (insertion depth). The depth of the can be grasped.
The display device 30 may not only display the captured image but also record the captured image on a recording medium that is not illustrated.

Thus, the crack investigation method provides the operator with an image in which the cracked portion is expressed in a fluorescent color, thereby making it possible to easily recognize whether or not the crack has occurred. Moreover, if a wider-angle image is captured as the captured image, the field of view for investigating the inside of the hole is further expanded, so that the presence or absence of cracks can be easily and quickly confirmed.
Returning to FIG. 1, the description of the procedure of the crack investigation method SA will be continued.

If no crack is observed in the observation in step S5 (No in step S6), the crack investigation is terminated. On the other hand, when a crack is observed (Yes in step S6), the crack investigation method SA proceeds to a crack measurement process.

[Detection process (measurement process)]
When a crack is observed in step S5 (Yes in step S6), the crack investigation method SA inserts an imaging device equipped with a side-view camera into the hole drilled in the second drilling step, and images the measurement device. By analyzing the image, the width of the crack is measured (step S7). At this time, when inserting the endoscope, the operator measures the depth from the surface of the concrete structure to the position where the crack is generated, based on the inserted depth (insertion depth).

In addition, in the detection process (observation process) of step S5, when the depth to the position where the crack has already occurred is measured, the measurement is not performed here, and the endoscope is inserted to the measured depth. do it. As a result, the endoscope can be quickly inserted to the position where the crack width is measured, and the crack investigation time can be shortened.

In this measurement process, for example, an endoscope provided with an image pickup unit for picking up a stereo image for side view can be used as the image pickup apparatus. In this measurement step, the size (width) of the crack is measured by sequentially inserting the endoscope cable into the hole and analyzing the captured stereo image.

Here, the detection process (measurement process) will be described in more detail with reference to FIG.
As shown in FIG. 11A, in the measurement process, an endoscope 40B and a measuring device 30B that measures the size of a crack from a stereo image captured by the endoscope 40B are used.
That is, in the crack investigation method, as shown in FIG. 11A, the inside of the hole drilled in the concrete structure Co is imaged with the endoscope 40B. The image captured by the endoscope 40B is transmitted to the measuring device 30B via a cable and analyzed, whereby the size of the crack is measured.

Here, as shown in FIG. 11B, the endoscope 40B is provided with an optical adapter Sv that captures a stereo image for side view (lateral direction) at the tip.
The optical adapter Sv includes cameras C _L and _CR and a light emitting unit L on the side surface side.

Camera C _L, C _R is for imaging the different stereo image parallax.
Emitting portion L is for camera C _L, C _R emits light for imaging an interior bore. The light emitting portion L is the same as the light emitting portion L described with reference to FIG.

The measuring device 30B measures the size (width) of a crack by analyzing a stereo image captured by the endoscope 40B.
Here, the stereo image, for example, as shown in FIG. 9 (c), the camera different two viewpoint position _C L, _{C R} the two images _F L captured by a _{F R.} Measuring device 30B displays the stereo image _F L, the _{F R} on the screen.

Then, the measuring device 30B, the operator, one of the images on the screen (e.g., image F _R) on, point 2 for specifying the width of the crack locations are represented by fluorescent color (e.g., the image F _R (P _R1 , P _R2 ) are designated, the distance between the two points is calculated and the value is displayed.
Note that a general method can be used as a method of measuring the distance between two points designated in the stereo image. That is, the distance between two points may be calculated by calculating the position of the corresponding three-dimensional coordinates (xyz coordinates) from the stereo image for each designated point, and obtaining the distance between the two three-dimensional coordinate positions.

Here, with reference to FIG. 12 (refer to FIG. 11 as appropriate), a method of calculating the three-dimensional coordinates (xyz coordinates) of one point designated from the stereo image will be described. The lens _L L, _{L R} is the camera _C L described in FIG. 11, respectively, the _{C R} of the lens. The focal length of each lens is f, and the distance between the lenses is d.
Note that the image is an image _F L shown in FIG. 11, the _{F R,} the horizontal and vertical direction in FIG. 12, to be imaged on the lens _L L, the imaging element away from the _{L R} by the focal length f (not shown) (Positive and negative in x direction and y direction) are reversed.

Here, as shown in FIG. 12 (a), the pixels on the image sensor (not shown) corresponding to the image point F designated by _R P _R1 shown in FIG. 11 (c) is a positive x-axis from the image center Assume that the distance a is away in the direction. The pixel on the image sensor (not shown) corresponding to the point P _L1 of image F _L showing the same position as the point P _R1 image F _R has spaced negative direction of the x-axis by a distance b from the image center Shall.
Incidentally, the point P _L1 of image F _L showing the same position as the point P _R1 image F _R, the measurement device 30B is determined by the block matching image feature in the pixel area of a predetermined size to explore the regions similar be able to.

Further, as shown in FIG. 12 (b), the pixels on the image sensor (not shown) corresponding to the image point F designated by _R P _R1 shown in FIG. 11 (c) is, the positive direction of the y-axis from the image center Is a distance c.
Thus, when a, b, c, and d are known information, the measuring device 30B, based on the principle of triangulation, as shown in the following formula (1), the designated point P _The three-dimensional coordinates (x, y, z) corresponding to _R1 are calculated.

Thus, the measuring device 30B calculates the three-dimensional coordinates (x, y, z) of one point out of the two points that specify the width of the cracked portion. Similarly, the measuring device 30B designates the other one point (for example, _PR2 on the image _FR ) of the two points that specify the width of the cracked portion, so that the three-dimensional coordinates (x , Y, z).
Then, the measuring device 30B _(here, P _{R1, P R2)} points designated 2 by calculating the distance of the three-dimensional coordinates of (x, y, z), determining the width of the crack locations. In addition, since this distance is a value based on the pixel of the image sensor, it is not necessary to actually convert it to an actual distance according to the resolution of the image sensor.

By using the method described above, cracks inside the hole drilled in the concrete structure can be observed with a fluorescent color, and the presence or absence of cracks can be quickly confirmed.
Further, in this method, even when a corner defect is generated at a cracked part due to microfracture by drill drilling, the cornered chipped part can be scraped off, and the cracked part can be accurately exposed to the surface inside the hole. Thus, this method can accurately measure the size and position of cracks generated in the concrete structure.

In addition, although it does not specifically limit here about the process after a crack evaluation, For example, if a crack does not exist, what is necessary is just to fill a hole with methyl methacrylate resin or concrete again. Thus, since this method is a microdestructive inspection, the time and cost of repairing a concrete structure can be reduced compared with the conventional destructive inspection which extracts a core sample.

In addition, since this method can accurately measure the location where a crack occurs, when repairing a concrete structure, it can be repaired without waste by shaving and repairing the portion where the crack occurred.
As mentioned above, although the crack investigation method of the concrete structure which concerns on embodiment of this invention was demonstrated, this invention is not limited to this procedure. Hereinafter, modifications of the present invention will be described.

[Modified example of crack investigation method for concrete structures]
Here, in the press-fitting process of step S2 shown in FIG. 1, the methyl methacrylate resin mixed with the fluorescent dye is press-fitted. However, the member to be press-fitted in this press-fitting step is not particularly limited as long as it is a liquid member having a specific color after curing.

For example, instead of methyl methacrylate resin mixed with fluorescent dye, other synthetic resins mixed with fluorescent dye (for example, acrylic resin, epoxy resin, etc.) may be used. These synthetic resins may be thermosetting resins or thermoplastic resins. In this way, by using an acrylic resin, an epoxy resin, or the like mixed with a fluorescent dye as the liquid member, the crack investigation method is the same as when using a methyl methacrylate resin. By imaging the surface of the hole drilled in the two drilling steps, the crack can be investigated in a state where the cracked portion is colored with a fluorescent color.

Also, instead of fluorescent dyes, colorants (dyes, pigments, etc.) of specific colors (for example, red, pink, etc.) that are different from the color of the concrete structure under investigation are synthesized with synthetic resins (methyl methacrylate resin, acrylic resin, You may mix in an epoxy resin etc.). In that case, using a light emitting part that emits white light instead of a light emitting part that emits ultraviolet rays as the light emitting part of the endoscope, the crack inside the hole is observed and measured as a spot imaged in a specific color. Can do.

Also, as a liquid member used in the press-fitting process, a blast furnace slag cement (ultrafine blast furnace) that is an inorganic injection material is used without using a synthetic resin (methyl methacrylate resin, acrylic resin, epoxy resin, etc.) that is an organic injection material. Slag cement cracking injection material (for example, TS crack filler)) may be used.
In this way, by using blast furnace slag cement as the liquid member, the crack investigation method detects the crack surface in the detection process by imaging the surface of the hole drilled in the second drilling process. It is possible to investigate cracks in the state.

This blast furnace slag cement is concrete using blast furnace slag fine powder as an admixture. This blast furnace slag cement hardens in about 24 to 30 hours and develops a blue color. Therefore, in the detection process (observation process, measurement process) of steps S5 to S7 shown in FIG. 1, a light emitting unit that emits white light is used as the light emitting unit of the endoscope instead of the light emitting unit that emits ultraviolet rays. Thus, the crack inside the hole can be observed and measured as a spot imaged in blue.

Further, in this blast furnace slag cement, fine powder of blast furnace slag reacts with calcium hydroxide produced by cement hydration reaction, thereby densifying the hardened body structure. Therefore, the blast furnace slag cement is resistant to water and can be used in a wet environment and a leaked environment.
On the other hand, the synthetic resin, which is an organic injection material, is vulnerable to water, so the inside of the hole must be used in a dry environment. However, since the synthetic resin has a high viscosity, the liquid of the liquid member press-fitted in the press-fitting process can be used without using the sealing plug 22 as shown in FIG. No one will occur.
Therefore, the liquid member to be press-fitted in the press-fitting process may be appropriately selected depending on the perforating direction and the dry state inside the hole.

In addition, here, as shown in steps S5 to S7 in FIG. 1, the observation process (step S5) is performed as the detection process, and the measurement process (step S7) is performed at the stage where cracks are observed. .
However, it is not always necessary to perform the observation process in the detection process. For example, after the second drilling process (step S4), the observation process may be omitted and the measurement process (step S7) may be performed.

In other words, in the crack detection method, in the detection step, an imaging device that captures a side-viewing stereo image is used as an imaging device, and the stereo image is analyzed as a specific color by analyzing the stereo image. Only the measurement process of measuring the width of the imaged crack and specifying the position of the crack by the insertion depth of the distal end portion of the endoscope may be performed.
By this procedure, the crack investigation method can measure the width of the crack from a stereo image captured by the imaging unit of the endoscope. Moreover, this crack investigation method can specify the position of a crack by the depth inserted to the crack location of the front-end | tip part of an endoscope.

In addition, the detection process may be performed by performing only the observation process (step S5) without performing the measurement process (step S7) and examining only the presence or absence of cracks. Even in this case, the present investigation method can visually examine the cracked state in a state where there is no corner chipping.

Here, as shown in steps S5 to S7 in FIG. 1, the observation process (step S5) and the measurement process (step S7) are sequentially performed as the detection process.
However, the detection step may be performed simultaneously with the observation step and the measurement step.

That is, in the detection step, as an imaging device, an endoscope provided with an imaging unit that captures a direct-view image and an imaging unit that captures a side-viewing stereo image at the distal end portion is used to check for cracks from the image. While observing and analyzing the stereo image, the width of the crack captured as the specific color may be measured, and the position of the crack may be specified by the insertion depth of the distal end portion of the endoscope.

In the detection process in which the observation process and the measurement process are performed simultaneously, for example, as an imaging apparatus that images the inside of the hole, an imaging unit that captures a direct-view image as illustrated in FIG. 13 and a stereo image for side-view are captured. An endoscope 40C provided with an imaging unit at the tip may be used.

As illustrated in FIG. 13, the endoscope 40C includes an optical adapter DSv that includes an imaging unit that captures an image for direct viewing (forward direction) and an imaging unit that captures a stereo image for side viewing (lateral direction). It is formed as.

The configuration for direct viewing of the optical adapter DSv (camera C, light emitting unit L) of the endoscope 40C is the same as the configuration of the optical adapter Dv shown in FIG. Further, the configuration for side viewing of the optical adapter DSv (camera C _L , C _R , light emitting unit L) of the endoscope 40C is the same as the configuration of the optical adapter Sv shown in FIG. .

As an image the endoscope 40C is captured, the image captured by the camera C, the camera C _L, and the stereo image captured by C _R, is displayed on the screen of the not shown measuring device. Note that the image captured by the camera C is the same image as that described with reference to FIG. In addition, the stereo image captured by the cameras C _L and _CR is the same image as that described with reference to FIG.
That is, a measuring device (not shown) displays a direct-view image and a side-view stereo image in respective areas that are divided on the screen. Of course, each image may be switched to display a direct-view image or a side-view stereo image on the entire screen.

As described above, the optical adapter DSv including the imaging unit that captures an image for direct viewing (forward direction) and the imaging unit that captures a stereo image for side viewing (lateral direction) at the distal end portion of the endoscope 40C. By using this, in the detection step, the operator searches for a cracked portion quickly by visually recognizing an image for direct viewing. And in the stage which found the crack location, an operator designates two points which identify a crack in the stereo image for side view, and a measuring device (not shown) is the distance between two points, ie, The size (width) of the crack is calculated and the value is displayed on the screen.
At this time, the operator can specify the position (depth) of the crack by measuring the depth at which the distal end portion of the endoscope 40C is inserted.

According to this cracking investigation method, it is possible to quickly find (observe) a crack inside a concrete structure with a color different from that of the concrete structure under investigation, and to reduce the width of the crack inside the concrete structure. From a stereo image, it can be measured accurately.

Further, as the tool mounting portion 18A, for example, as shown in FIG. 14, the position of the holder portion 18b may be configured to move vertically with respect to the support column 12. That is, the tool mounting portion 18A may be configured such that the position of the holder portion 18b and the sliding portion 18a can be adjusted by the extendable arm 18e. The telescopic arm 18e has, for example, a first holder part 18b and a second holder part 18f as a holding mechanism, and is configured to be fixed at a predetermined position by screws (not shown). The telescopic arm 18e is set in advance so that the endoscope 40 attached to the second holder portion 18f in the extended state is positioned on the center axis of the hole attached to the first holder portion 18b and perforated. This makes positioning easy. Therefore, the tool mounting portion 18A mounts the drilling machine 13 on the first holder portion 18b via the tool fixture 19 as described above, and mounts the endoscope 40 on the second holder portion 18f. The two tools are held at the same time. Then, after the tool mounting portion 18A is punched by the punching machine 13, the telescopic arm 18e is extended in a direction perpendicular to the drilling direction, so that the endoscope 40 can be placed on the center axis of the hole immediately drilled. Can be performed smoothly. In FIG. 14, the first holder portion 18 b and the second holder portion 18 f have been described as holding mechanisms. However, the configuration further includes a third holder portion (not shown), for example, on the circumference. A cylindrical configuration (holding mechanism) having a plurality of holder portions may be used.

Furthermore, although it has been described that the tool mounting portion 18 is mounted via the tool fixtures 19, 29, and 49 having the same outer dimensions, for example, the holder portion 18b directly on the basis of the outer dimensions of the syringe 20. The perforator 13 and the endoscope 40 may be attached to the holder portion 18b via the tool fixtures 19 and 49. Further, when the positioning operation is not necessary when the syringe 20 and the endoscope 40 are used, the punching machine 13 is moved to the rear side of the support column 12 to secure a working space and press-fitting step (S2, S2). You may make it perform S3) and an inspection process (S5, S6).

S crack investigation system SA crack investigation method S1 first drilling process S2, S3 press-fitting process S4 second drilling process S5, S6 detection process (observation process)
S7 Detection process (measurement process)
Co Concrete Structure 10 Base 11 Vacuum Pump 12 Strut 13 Punching Machine 14 Centering Rod 15 Right Angle Jig 16 Small Diameter Bit (Diamond Bit)
17 Rod 18 Tool mounting part 19 Tool fixing tool (insertion aid)
20 Syringe (press-fit device)
21 Needle 22 Seal plug 29 Tool fixture (insertion aid)
30 Display device 30B Measuring device 40, 40B, 40C Endoscope 49 Tool fixture (insertion aid)
C, C _L , C _R camera L Light emitting part Dv Optical adapter (For direct viewing)
Sv optical adapter (for side view)
DSv optical adapter (for direct / side view)

Claims (11)

1. A crack investigation method for investigating cracks in a concrete structure,
   A first drilling step of drilling a hole having a depth to be investigated in the concrete structure with a predetermined hole diameter by a drilling machine;
   A press-fitting step of press-fitting a liquid member having a specific color at the time of curing into the hole drilled in the first perforation step;
   A second drilling step of drilling a hole of the depth to be investigated with a hole diameter larger than the hole diameter after the liquid member is hardened with respect to the hole into which the liquid member is press-fitted in the press-fitting step;
   A detection step of detecting the crack by inserting an imaging device into the hole drilled in the second drilling step and detecting the specific color;
   A method for investigating cracks in a concrete structure characterized by comprising:
2. The method for investigating cracks in a concrete structure according to claim 1, wherein the liquid member is a synthetic resin mixed with the colorant of the specific color.
3. The method for investigating cracks in a concrete structure according to claim 1, wherein the liquid member is blast furnace slag cement.
4. In the detection step, as the imaging device, an endoscope having an imaging unit that captures a stereo image for side view is provided at a distal end portion, and the stereo image is imaged and imaged as the specific color. The concrete according to any one of claims 1 to 3, further comprising a measuring step of measuring a width of a crack and specifying a position of the crack based on an insertion depth of a distal end portion of the endoscope. Method for investigating cracks in structures.
5. The detection step includes an observation step of observing the presence or absence of the crack from the image before the measurement step, using an endoscope provided with an image pickup unit for picking up a direct-view image as the imaging device. The method for investigating cracks in a concrete structure according to claim 4, comprising:
6. In the detection step, as the imaging device, an endoscope including an imaging unit that captures an image for direct viewing is provided at the tip, and the presence or absence of the crack is observed from the image, and the tip of the endoscope is An observation process for identifying the position of the crack according to the insertion depth;
   As the imaging device, an endoscope having an imaging unit for capturing a side-viewing stereo image at a distal end portion is inserted, and the endoscope is inserted up to a crack position specified in the observation step, and the stereo image By measuring the width of the crack imaged as the specific color,
   The method for investigating cracks in a concrete structure according to any one of claims 1 to 3, characterized by comprising:
7. The detection step uses, as the imaging device, an endoscope having an imaging unit that captures a direct-view image and an imaging unit that captures a side-viewing stereo image at a distal end, and the crack is detected from the image. Observing the presence / absence and analyzing the stereo image to measure the width of the crack imaged as the specific color and identifying the position of the crack by the insertion depth of the tip of the endoscope The method for investigating cracks in a concrete structure according to any one of claims 1 to 3, wherein the crack is investigated.
8. A crack investigation system for investigating cracks in a concrete structure,
   A perforator that perforates holes of the same central axis by exchanging bits having different hole diameters along a pillar provided with a guide in a perforation direction installed in the concrete structure;
   A press-fitting device for press-fitting a liquid member having a specific color at the time of curing into a hole first perforated by the perforator;
   An imaging device that inserts into a hole drilled with a hole diameter larger than the hole first drilled by the drilling machine, and images the inside of the hole;
   A crack investigation system for concrete structures characterized by comprising:
9. It further includes a tool mounting portion for positioning the punching machine, the press-fitting device and the imaging device on the central axis and detachably holding at least one of the punching machine, the press-fitting device and the imaging device. The crack investigation system for a concrete structure according to claim 8.
10. The tool mounting portion has an inner diameter that is larger than an outer diameter in a short direction of the punching machine, the press-fitting device, and the imaging device, and at least one of the punching machine, the press-fitting device, and the imaging device is provided. The crack inspection system for a concrete structure according to claim 9, wherein the crack is investigated through an insertion aid that fills a gap between the outer diameter and the inner diameter in the short direction.
11. The tool mounting portion includes a holding mechanism for simultaneously holding at least any two of the drilling machine, the press-fitting device, and the imaging device in a direction orthogonal to a central axis, and the holding mechanism is The system for investigating cracks in a concrete structure according to claim 9, wherein the system is capable of moving in a direction perpendicular to the axis.

Images