JP6932614B2 - Crack continuity judgment system, judgment method and judgment program, and crack detection device, detection method and detection program - Google Patents

Description

The present invention relates to a crack detection device, a crack continuity determination system, a crack detection method and a crack detection program.

In dam construction, in order to improve the water impermeability of the foundation ground, grouting is performed by forming a bore hole in the foundation ground and injecting grout to close the cracks in the foundation ground. Patent Document 1 proposes to calculate the distribution density of cracks from data such as the strike and dip symbol of cracks in a bore hole, and to determine the specifications of grouting based on the calculated distribution density.

Japanese Unexamined Patent Publication No. 2014-21374

The data such as the strike and dip symbol of the crack in Patent Document 1 is currently measured manually from the crack on the image by the measurer looking at the image obtained by photographing the inside of the bore hole. Therefore, there is a problem that it takes time to acquire crack data and the measurement accuracy differs depending on the measurer.

An object of the present invention is to detect cracks quickly and with constant accuracy.

According to an aspect of the present invention, the crack detection system analyzes the developed image obtained by photographing the inner walls of the first and second bore holes formed in the ground, and obtains a sinusoidal waveform based on the crack from the developed image. A crack detection device that detects cracks in the first and second boreholes and acquires the strike and inclination of the cracks from the extracted sinusoidal waveform, and cracks in the first and second boreholes detected by the crack detection device. An index calculation unit that calculates an index for determining the continuity between each other, and a continuity determination unit that determines the continuity between cracks in the first and second boreholes based on the index calculated by the index calculation unit. , Equipped with.
Further, according to another aspect of the present invention, the crack continuity determination method analyzes the developed image obtained by photographing the inner walls of the first and second bore holes formed in the ground, and cracks are obtained from the developed image. The sine waveform based on is extracted, and the cracks in the first and second boreholes are detected and the strike and inclination of the cracks are obtained from the sine waveform, and the continuity of the cracks in the detected first and second boreholes is obtained. An index for determination is calculated, and the continuity of cracks in the first and second bore holes is determined based on the calculated index.
Further, according to another aspect of the present invention, the crack continuity determination program analyzes the developed image obtained by photographing the inner walls of the first and second bore holes formed in the ground, and cracks are obtained from the developed image. The sine waveform based on the above is extracted, and the cracks in the first and second boreholes are detected from the sine waveform, and the strike and inclination of the cracks are obtained, and the continuity of the cracks in the detected first and second boreholes is obtained. An index for determination is calculated, and a computer is made to execute a process of determining the continuity of cracks in the first and second boreholes based on the calculated index.
Further, according to another aspect of the present invention, the crack detection device analyzes the developed image obtained by photographing the inner wall of the bore hole formed in the ground and extracts a sinusoidal waveform based on the crack from the developed image. A sine waveform extraction unit and a strike inclination acquisition unit that detects a crack in a bore hole and acquires the strike and inclination of the crack from the sine waveform based on the crack extracted by the sine waveform extraction unit are provided to extract the sine waveform. The unit superimposes a plurality of temporary sine waveforms on the developed image , calculates a representative value of brightness in a plurality of pixels through which each of the plurality of temporary sine waveforms passes, and calculates a representative value for each of the plurality of temporary sine waveforms. Based on the values , one of a plurality of tentative sine waveforms is extracted as a crack-based sine waveform.

Further, according to another aspect of the present invention, the crack detection method analyzes a developed image obtained by photographing the inner wall of a bore hole formed in the ground, and extracts a sinusoidal waveform based on the crack from the developed image. The sine waveform extraction step includes a plurality of tentative sine waveforms. The waveform is superimposed on the developed image, the representative value of the brightness in the plurality of pixels through which each of the plurality of temporary sine waveforms passes is calculated for each of the plurality of temporary sine waveforms, and the plurality of temporary sine waveforms are calculated based on the calculated representative values. One of the sine waveforms of is extracted as a sine waveform based on a crack.

Further, according to another aspect of the present invention, the crack detection program analyzes the developed image obtained by photographing the inner wall of the bore hole formed in the ground and extracts a sinusoidal waveform based on the crack from the developed image. It is a crack detection program for causing a computer to execute a sine waveform extraction process for performing a sine waveform extraction process and a strike inclination acquisition process for detecting a crack in a bore hole and acquiring the strike and inclination of the crack from the sine waveform based on the crack. In the sine waveform extraction process, a plurality of temporary sine waveforms are superimposed on the developed image, and a representative value of brightness in a plurality of pixels through which each of the plurality of temporary sine waveforms passes is calculated for each of the plurality of temporary sine waveforms. One of a plurality of tentative sinusoidal waveforms is extracted as a sinusoidal waveform based on the crack based on the representative value obtained.

According to the present invention, cracks can be detected quickly and with constant accuracy.

It is the schematic which shows the structure of the crack detection apparatus which concerns on embodiment of this invention. (A) is a perspective view showing a bore hole penetrating two cracks, and (b) is a developed image obtained by photographing and developing the wall surface of the bore hole shown in (a). It is a figure for demonstrating the strike and inclination of a crack. It is a block diagram which shows the structure of the crack detection apparatus which concerns on embodiment of this invention. It is a flowchart which shows the process of extracting the sine waveform which approximates a crack from the developed image. (A) is a developed image of the inner wall of the bore hole, and (b) is a graph showing a representative Gray luminance value. It is a flowchart which shows the process of acquiring the strike and the inclination of a crack. It is a flowchart which shows the process of acquiring the width of a crack. (A) is an enlarged view of the developed image of the inner wall of the bore hole, and (b) is a graph showing the Gray brightness. It is a simulated enlarged view which sees through the bore hole parallel to the strike of the crack. It is a flowchart which shows the process of acquiring the color information of a crack. It is a block diagram which shows the structure of the crack continuity determination system which concerns on embodiment of this invention. It is a figure explaining the index for determining the continuity between cracks. It is a flowchart which shows the process of calculating the apparent depth difference between cracks. It is a flowchart which shows the process of calculating the intersection angle of the normal vector between cracks. It is a flowchart which shows the process of calculating the width difference between cracks. It is a flowchart which shows the process of calculating the color information difference between cracks. It is a flowchart which shows the process of calculating the Ludion value difference between cracks. It is a flowchart which shows the process of determining the continuity of cracks. An example of displaying the judgment result of the continuity between cracks is shown. It is a figure explaining the inter-plane distance between cracks.

Hereinafter, the crack detection device 100, the crack continuity determination system 1000, the crack detection method, and the crack detection program according to the embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing the foundation ground 1 in a dam or the like. In the dam construction, in order to improve the water impermeability of the foundation ground 1, a plurality of bore holes 2 are formed in the foundation ground 1 and grout is injected to close the cracks 3 in the foundation ground 1. In grouting, first, a plurality of primary bore holes 2 are formed on the foundation ground 1 at predetermined intervals, and if necessary, higher-order bore holes such as secondary bore holes and tertiary bore holes are additionally formed between the primary bore holes 2. .. It is desirable that the position and number of higher-order bore holes are determined according to the size and number of cracks 3 in the foundation ground 1.

The crack continuity determination system 1000 (see FIG. 12) according to the present embodiment estimates the crack 3 based on the information of the crack 3 in the inner wall of the bore hole 2 formed in advance. By estimating the crack 3 by the crack continuity determination system 1000, it becomes possible to easily determine the number and position of the additional higher-order bore holes 2. Further, the crack detection device 100 detects the crack 3 in the inner wall of the bore hole 2 formed in the foundation ground 1 and acquires information on the crack 3 such as the strike and inclination of the crack 3. By acquiring the information of the crack 3 in the bore hole 2 by the crack detection device 100, the estimation accuracy of the crack 3 in the crack continuity determination system 1000 can be improved.

First, the crack detection device 100 and the crack detection method will be described with reference to FIGS. 1 to 11. The crack detection device 100 includes a computer 20 as an analysis means for analyzing the developed image obtained by the borehole camera 10 as an image creation means. The borehole camera 10 photographs the inner wall of the borehole 2 to create a developed image. The computer 20 includes a CPU (central processing unit) that performs arithmetic processing, a ROM (read-only memoryY) in which a program executed by the CPU is stored in advance, data input from the borehole camera 10, CPU arithmetic results, and the like. RAM (random access memoryY) for storing the data, and the like.

The borehole camera 10 is formed so that the inner wall of the borehole 2 can be photographed in 360-degree color in the circumferential direction. The borehole camera 10 is attached to one end of a wire 12 wound around the winch 11, and moves up and down in the borehole 2 by driving the winch 11. By photographing the inner wall of the bore hole 2 while moving the bore hole camera 10 up and down, a color development image (see FIG. 2B) over the entire depth of the bore hole 2 can be obtained.

FIG. 2A is a perspective view showing a bore hole 2 penetrating the two cracks 3a and 3b, and FIG. 2B is an image of the wall surface of the bore hole 2 shown in FIG. 2A and developed. It is a developed image obtained by. As shown in FIG. 2A, the cracks 3a and 3b form an elliptical shape on the inner wall of the bore hole 2 according to the strike and inclination.

FIG. 3 is a diagram for explaining the “strike” and “inclination” of the crack 3. The "strike" is the direction in which the line of intersection IL formed by the intersection of the crack 3 and the virtual horizontal plane HS extends. Here, the "strike" is expressed as the angle θ [deg] between the line of intersection IL and the axis extending in the north-south direction, and the west (W) direction is the positive direction with respect to the north (N). Further, the "inclination" is a direction in which the perpendicular line PL orthogonal to the line of intersection IL extends along the crack 3. Here, "inclination" is expressed as an angle φ [deg] between the perpendicular line PL and the virtual horizontal plane HS.

As shown in FIG. 2B, in the developed image, the cracks 3a and 3b draw a shape similar to a sine wave. Specifically, the directions of the upper peak point PUa and the lower peak point PLa of the crack 3a in the developed image are determined according to the strike θa of the crack 3a, and according to the inclination φa of the crack 3a and the radius R of the bore hole 2. , The amplitude Aa of the crack 3a in the developed image is determined. Similar to the crack 3a, the crack 3b also draws a shape close to a sine wave according to the strike θb and the inclination φb of the crack 3b in the developed image. The crack detection device 100 (see FIG. 1) acquires strikes θa, θb and slopes φa, φb of the cracks 3a, 3b based on the shapes of the cracks 3a, 3b in the developed image.

As shown in FIG. 4, the computer 20 includes an image capturing unit 21 that captures an image, a sinusoidal waveform extracting unit 22 that extracts a sinusoidal waveform that approximates the cracks 3a and 3b from the developed image, and a strike and dip symbol θa of the cracks 3a and 3b. , Θb and a strike and dip symbol acquisition unit 23 that acquires the inclinations φa and φb. The computer 20 is connected to the borehole camera 10 via the signal line 13, and the color development image created by the borehole camera 10 is captured by the image capture unit 21 into the computer 20. Hereinafter, the processing performed by the sinusoidal waveform extraction unit 22 and the strike and dip symbol acquisition unit 23 will be specifically described.

First, the sine waveform extraction process performed by the sine waveform extraction unit 22 will be described with reference to FIGS. 2 to 6.

As shown in FIG. 5, first, in step S501, the captured color development image is converted into a grayscale image. Specifically, the weighted average of the brightness of red (R), green (G), and blue (B) is calculated for each pixel in the color development image. This weighted average is the Gray luminance of each pixel in the grayscale image. By converting the color development image into a grayscale image, the brightness of each pixel becomes only the Gray brightness, and it becomes easy to compare the crack determination threshold value described later with the brightness of the development image.

Next, in steps S502 to S506, a sine waveform that approximates the cracks 3a and 3b (see FIG. 2B) is obtained from the grayscale image. Specifically, the sine waveform represented by the function F (Y) of the following equation (1) is superimposed on the grayscale image, and the function is based on the average value of the Gray brightness of a plurality of pixels through which the sine waveform passes. It is determined whether or not the sinusoidal waveform represented by F (Y) is close to the cracks 3a and 3b.

F (Y) = Z + R × tanφ × sin (Y−θ) ・ ・ ・ ・ Equation (1)
Here, Y: an angle [deg] representing an arbitrary direction with respect to north (N).
Z: Depth [m]
R: Radius of bore hole 2 [m]
θ: Strike [deg]
φ: Inclination [deg]

Hereinafter, the process of obtaining a sine waveform similar to the cracks 3a and 3b performed in steps S502 to S506 will be described in more detail.

In FIG. 2, the depth Z in the function F (Y) is Z1, the R × tan φ representing the amplitude of the sine waveform is A1, and the sine waveform SW1 when the strike θ is θ1 is shown by a chain line. Usually, the Gray brightness of the cracks 3a and 3b is smaller than the Gray brightness of the portion other than the cracks 3a and 3b. Therefore, the smaller the average value of the Gray brightness of the plurality of pixels through which the sinusoidal waveform SW1 passes, the closer the sinusoidal waveform SW1 is to the cracks 3a and 3b. That is, it is possible to determine whether or not the sinusoidal waveform SW1 is close to the cracks 3a and 3b based on the average value of the Gray luminances of the plurality of pixels through which the sinusoidal waveform SW1 passes.

In order to obtain a sinusoidal waveform SW1 that approximates the cracks 3a and 3b in the developed image, first, in step S502, the depth Z is set to a constant value and the strike θ is changed in the range of −180 to +180 [deg] (for example, 1). The inclination φ is changed in the range of 0 to 90 [deg] with each [deg] (for example, every 1 [deg]). At this time, the sine waveforms under the conditions of strike θ and inclination φ are superimposed on the grayscale image, and the average value of the Gray luminances of the plurality of pixels through which the sine waveform passes is calculated.

Next, in step S503, the minimum value of the plurality of calculated gray luminance average values and the strike θ and the slope φ from which the minimum value of the gray luminance average values are calculated are acquired. The sinusoidal waveform from which the minimum value of the Gray brightness average value is calculated is the sinusoidal waveform that most closely approximates the crack when there is a crack at the depth Z. In the following, the minimum value of the average Gray luminance value at the depth Z will be referred to as a “representative Gray luminance value” at the depth Z.

Next, in step 504, it is determined whether or not the representative Gray luminance value has been acquired over a predetermined depth range. The predetermined depth range is, for example, the total depth of the bore hole 2. The predetermined depth range may be changeable by the operator.

If it is determined in step S504 that the representative Gray luminance value has not been acquired over a predetermined depth range, the depth Z is changed by, for example, 0.01 [m] in step S505, and step S502, Execute S503 again. As a result, the representative Gray luminance value is acquired over a predetermined depth range. If it is determined in step S504 that the representative Gray luminance value has been acquired over a predetermined depth range, step S506 is executed.

FIG. 6B shows a graph showing representative Gray luminance values obtained by executing steps S502 and S503 over a predetermined depth range. As shown in FIGS. 6A and 6B, the representative Gray luminance value is usually smaller in the depth section where the cracks 3a and 3b are present than in the other depth sections. Therefore, the crack detection device 100 determines the presence or absence of cracks 3a and 3b based on the representative Gray luminance value.

As shown in FIGS. 5 and 6, in step S506, the representative Gray luminance value at each depth Z is compared with the predetermined crack determination threshold value, and when the representative Gray luminance value is equal to or less than the crack determination threshold value. It is determined that there are cracks 3a and 3b. Further, it is determined that the sinusoidal waveforms SWa and SWb for which the representative Gray luminance value equal to or less than the crack determination threshold value is calculated are sinusoidal waveforms that approximate the cracks 3a and 3b. The crack determination threshold value may be changeable by the operator.

As described above, the sine waveform is extracted from the developed image based on the cracks 3a and 3b, and the crack extraction process is completed.

Next, the strike and dip symbol acquisition process performed by the strike and dip symbol acquisition unit 23 will be described with reference to FIGS. 6 and 7.

As shown in FIGS. 6A and 6B, the cracks 3a and 3b have a width in the depth direction of the bore hole 2. Therefore, first, in step S701 (see FIG. 7), the representative depths Za and Zb of the cracks 3a and 3b are obtained. Specifically, in each depth section ZRa, ZRb where it is determined that there are cracks 3a, 3b, the depth Z at which the representative Gray luminance value is minimized is obtained, and the depth Z is defined as the representative depth Za of the cracks 3a, 3b. , Zb. From the above, the representative depths Za and Zb of the cracks 3a and 3b can be obtained.

Next, in step S702 (see FIG. 7), the strike θ and the inclination φ are obtained from the sinusoidal waveform determined to be close to the cracks 3a and 3b at the representative depths Za and Zb. Specifically, since the strike θ and the inclination φ for calculating the representative Gray luminance value for each depth Z are acquired in step S503 (FIG. 5), the strike θ acquired at the representative depths Za and Zb is acquired. And read out the slope φ.

As described above, the strike θ and the inclination φ in the function F (Y) correspond to the elliptical strike and inclination drawn on the inner wall of the bore hole 2. Therefore, the strike θa and the inclination φa of the crack 3a can be obtained by regarding the strike θa and the inclination φ obtained at the representative depth Za as the strike θa and the inclination φa of the crack 3a (see FIG. 2). Similarly, the strike θb and the inclination φb of the crack 3b can be obtained by regarding the strike θb and the inclination φ acquired at the representative depth Zb as the strike θb and the inclination φb (see FIG. 2) of the crack 3b.

As described above, the strikes θa and θb and the inclinations φa and φb (see FIG. 2) of the cracks 3a and 3b in the inner wall of the bore hole 2 are acquired from the sine waveform extracted by the sine waveform extraction unit 22, and the strike and dip symbol acquisition process is performed. finish.

In the present embodiment, in step S502, the depth Z is set to a constant value, the strike θ is changed, and the inclination φ is changed to calculate the average value of the Gray brightness. However, the strike θ and the inclination φ are calculated respectively. The average value of the Gray brightness may be calculated by setting the value to a constant value and changing the depth Z. In this case, in step S503, a section in which the average value of the Gray brightness values continuously falls below the threshold value at a predetermined depth or more in the depth direction is extracted as a crack candidate section, and the minimum value of the Gray brightness average value in the crack candidate section (representative Gray). Luminance) and the depth Z from which the representative Gray luminance is calculated are acquired. Then, the crack candidate section and the representative Gray luminance value are acquired over a predetermined strike range and inclination range. Comparing crack candidate sections with strike θ and slope φ that differ by the analysis accuracy, if the depth distributions overlap at a predetermined depth or more, and one of the strike θ and slope φ is the same and the other is different by the analysis accuracy, they are the same. Judged as a crack section. All crack candidate sections that were not used to determine the same crack section are determined as individual crack sections. In this way, the strike and dip symbol acquisition process may be performed.

In the crack detection device 100, a sine waveform similar to the cracks 3a and 3b is extracted from the color development image created by the borehole camera 10 by the processing of the computer 20, and the cracks 3a and 3b are extracted from the extracted sine waveforms. The strikes θa and θb and the inclinations φa and φb are acquired. Therefore, the cracks 3a and 3b can be detected quickly and with a constant accuracy, and the strikes θa and θb and the inclinations φa and φb of the cracks 3a and 3b can be obtained.

The strikes θa and θb and the slopes φa and φb of the acquired cracks 3a and 3b are used in the crack continuity determination process described later.

In the crack continuity determination process described later, in addition to the strikes θa and θb and the inclinations φa and φb of the cracks 3a and 3b, the width and color information of the cracks 3a and 3b are used. The width and color information of the cracks 3a and 3b are acquired by the crack width acquisition unit 24 and the crack color information acquisition unit 25 (see FIG. 4) of the crack detection device 100, respectively. Hereinafter, the processes for acquiring the width and color information of the cracks 3a and 3b will be described.

First, the process of acquiring the width of the crack 3a performed by the crack width acquisition unit 24 will be described with reference to FIGS. 2, 8 to 10.

As shown in FIG. 2, the width of the crack 3a in the developed image is not constant with respect to the azimuth axis. Therefore, here, the width calculated based on the width WUa of the crack 3a at the upper peak point PUa and the width WUb of the crack 3a at the lower peak point PLa is acquired as the representative width of the crack 3a.

First, in step S801 (see FIG. 8), a sinusoidal waveform that approximates the crack 3a at the representative depth Za of the crack 3a is acquired. Specifically, since the strike θ and the inclination φ for calculating the representative Gray luminance value are acquired for each depth Z in step S503 (see FIG. 5), the strike θ and the strike θ acquired at the representative depth Za are obtained. A sine waveform is obtained by reading the slope φ and substituting it into the function F (Y).

Next, in step S802 (see FIG. 8), the width WUa of the crack 3a at the upper peak point PUa is obtained based on the Gray brightness. The process of obtaining the width WUa of the crack 3a will be described more specifically with reference to FIG.

FIG. 9A is an enlarged view of a grayscale image, showing the vicinity of the upper peak point PUa of the crack 3a. In FIG. 9A, a sinusoidal waveform SWa similar to the crack 3a is superimposed on the crack 3a at a representative depth Za, and a straight line L extending in the depth direction of the bore hole 2 through the upper peak point P of the sinusoidal waveform SWa is a chain line. It is shown. Further, FIG. 9B is a graph showing the Gray brightness for each depth along the straight line L.

As shown in FIGS. 9A and 9B, the Gray brightness along the straight line L is usually smaller in the depth section where the crack 3a exists than in the other depth sections. Therefore, in step S802 (see FIG. 8), the Gray brightness along the straight line L is compared with the predetermined crack width acquisition threshold value, and the length of the depth section in which the Gray brightness is equal to or less than the crack width acquisition threshold value is cracked. Obtained as a width WUa of 3a. The threshold value for acquiring the crack width may be changed by the operator.

By the above treatment, the width WUa of the crack 3a can be obtained.

Next, in step S803 (see FIG. 8), the width WLa of the crack 3a at the lower peak point PLa shown in FIG. 2 is obtained based on the Gray brightness. Since the process in step S803 is substantially the same as the process in step S802, the description thereof will be omitted here.

Next, in step S804, the average value of the width WUa and the width WLa of the crack 3a is calculated.

Here, the relationship between the width WUa and the width WLa of the crack 3a and the inclination φa of the crack 3a obtained from the developed image will be described with reference to FIG. FIG. 10 is a simulated enlarged view of the crack 3a in the bore hole 2 seen through in parallel with the strike. FIG. 10 shows a virtual crack 3a'in which the slope φa of the crack 3a is reduced.

The widths WUa and WLa obtained in steps S803 and S804 (see FIG. 8) correspond to the width of the crack 3a on the inner wall of the bore hole 2, that is, the width of the crack 3a in the depth direction of the bore hole 2. Therefore, the average value of the width WUa and the width WLa of the crack 3a corresponds to the width WAa of the crack 3a in the depth direction at the center of the bore hole 2. The width WAa of the crack 3a becomes larger as the inclination φ is larger, as is clear from a comparison between the crack 3a and the virtual crack 3a'. Therefore, in the crack continuity determination process described later, if the crack continuity is determined using the width WAa of the crack 3a, the determination accuracy may decrease due to the influence of the inclination φa of the crack 3a.

Therefore, in the crack detection device 100, the average value (width WAa) of the width WUa and the width WLa of the crack 3a is corrected in S805 (see FIG. 8) based on the inclination φa of the crack 3a. Specifically, the width WAa is corrected by multiplying the width WAa by the cosine value (cosφa) of the slope φa. As a result, the width WNa in the normal direction of the crack 3a at the center of the bore hole 2 is obtained. Hereinafter, the width WNa is also referred to as a "representative width WNa".

As a result, the representative width WNa of the crack 3a is acquired from the developed image, and the crack width acquisition process is completed. Since the process of acquiring the representative width of the crack 3b is substantially the same as the process of acquiring the representative width WNa of the crack 3a, the description thereof will be omitted here.

In the present embodiment, the average value (width WAa) of the width WUa and the width WLa of the crack 3a is calculated, and the width WAa is corrected by multiplying the cosine value (cosφa) of the slope φa of the crack 3a to correct the representative width WNa. However, the representative width WNa may be obtained by calculating the section length (apparent crack width) of the crack section and correcting it with the slope φa. In this case, the representative width WNa is calculated as an average crack width, not as an actual crack width.

In the crack detection device 100, the representative width WNa of the crack 3a is acquired from the developed image by the processing of the computer 20. Therefore, the representative width WNa of the crack 3a can be obtained quickly and with a constant accuracy.

Further, the crack detection device 100 obtains a representative width WNa in the normal direction of the crack 3a by correcting the width WAa of the crack 3a in the depth direction of the bore hole 2 by multiplying the cosine value of the inclination φ. Therefore, it is possible to obtain a width that is not affected by the inclination φa of the crack 3a.

Next, the crack color information acquisition process performed by the crack color information acquisition unit 25 will be described with reference to FIG. Although not shown, the color of the crack 3a is not constant with respect to the azimuth axis, similar to the width of the crack 3a shown in FIG. Therefore, here, the average value of the color information of the crack 3a at the upper peak point PUa and the color information of the crack 3a at the lower peak point PLa is acquired as the representative color information of the crack 3a.

First, as shown in FIG. 11, in step S1101, a sine waveform similar to the crack 3a is acquired at the representative depth Za of the crack 3a. Specifically, since the strike θ and the inclination φ for calculating the representative Gray luminance value are acquired for each depth Z in step S503 (see FIG. 5), the strike θ and the strike θ acquired at the representative depth Za are obtained. A sine waveform is obtained by reading the slope φ and substituting it into the function F (Y).

Next, in step S1102, the RGB luminance of the crack 3a at the upper peak point PUa shown in FIG. 9A is extracted from the color development image. Specifically, the RGB luminance along the straight line L is extracted in the depth section of the width WUa obtained in step S802 (see FIG. 8).

Next, in step S1103, the RGB color system is converted to the L * a * b * color system. As a result, the L * value, the a * value, and the b * value at the upper peak point PUa are calculated.

Next, in step S1104, the RGB luminance of the crack 3a at the lower peak point PLa shown in FIG. 2 is extracted from the developed color image. Next, in step S1105, the L * value, the a * value, and the b * value are calculated based on the RGB luminance at the lower peak point PLa. Since the processing in steps S1104 and S1105 is substantially the same as the processing in steps S1102 and S1103, the description thereof will be omitted here.

Next, in step S1106, the average values of the L * value, a * value, and b * value at the upper and lower peak points PUa and PLa are calculated, respectively, and these average values are used as the representative colors of the cracks 3a and 3b. Get as information.

As a result, the representative color information of the crack 3a is acquired from the developed image, and the crack color information acquisition process is completed. Since the process of acquiring the representative color information of the crack 3b is substantially the same as the process of acquiring the representative color information of the crack 3a, the description thereof will be omitted here.

In the present embodiment, the average value of the RGB brightness of the crack 3a at the upper peak point PUa and the RGB brightness of the crack 3a at the lower peak point PLa is obtained, but all the pixels on the sine wave are used. The average value of RGB luminance may be obtained.

In this way, the crack detection device 100 acquires the color information of the cracks 3a and 3b from the color development image by the processing of the computer 20. Therefore, the color information of the cracks 3a and 3b can be acquired quickly and with a constant accuracy.

Further, the crack detection device 100 extracts the RGB luminance in the depth section obtained in S802 (see FIG. 8). Therefore, it is possible to prevent the color information in the portions other than the cracks 3a and 3b from being extracted, and the color information in the cracks 3a and 3b can be acquired more accurately.

By the above processing of the crack detection device 100, the depth, strike, inclination, crack width and color information of the cracks 3a and 3b are acquired.

Next, the crack continuity determination system 1000 will be described with reference to FIGS. 12 to 20. The crack continuity determination system 1000 is obtained by carrying out an index calculated using crack information (crack depth, strike, inclination, width and color information) acquired by the crack detection device 100, or a so-called luzion test. Based on the index calculated using the Luzion value (Lu value), the continuity of the cracks is determined and the result is displayed.

The continuity determination threshold value may be set in advance for each index, and an index exceeding the continuity determination threshold value or an index smaller than the continuity determination threshold value may be excluded as an error value.

As shown in FIG. 12, the crack continuity determination system 1000 includes a crack information acquisition unit 31 that acquires crack information from the crack detection device 100, and an index calculation unit 33 that calculates an index for determining the continuity between cracks. And a continuity determination unit 34 for determining the continuity of the cracks. The index calculated by the index calculation unit 33 includes an apparent depth difference between cracks, an intersection angle of normal vectors, a width difference, a color information difference, and a luzion value difference. The continuity determination unit 34 determines the continuity between cracks based on the continuity determination score calculated using these indexes.

Hereinafter, the process of calculating the index for determining the continuity of the cracks and the process of determining the continuity of the cracks based on the continuity determination score calculated using these indexes are shown in FIGS. 13 to 13. A specific description will be given with reference to 18. FIG. 13 is a perspective view showing the first and second bore holes 2c and 2d. Here, an index for determining the continuity of one of the plurality of cracks detected in the first bore hole 2c, one of the cracks 3c, and one of the plurality of cracks detected in the second bore hole, 3d. The calculation will be described.

First, a case where the apparent depth difference between the cracks 3c and 3d is calculated as an index will be described.

Here, the "apparent depth difference" will be described with reference to FIG. The "apparent depth difference" is, for example, the depth at the intersection Pc where the virtual crack 3c'in which the crack 3c in the first bore hole 2c is linearly extended to the second bore hole 2d intersects the second bore hole 2d, and the crack 3d. The difference Dc from the depth of. Since the cracks usually extend substantially linearly in the foundation ground 1 (see FIG. 1), the smaller the apparent depth difference Dc, the higher the possibility that the cracks 3c and 3d are continuous. In other words, it is possible to determine the continuity between the cracks 3c and 3d by using the apparent depth difference between the cracks 3c and 3d as an index. Hereinafter, the case of calculating the apparent depth difference between the cracks 3c and 3d will be specifically described with reference to FIGS. 13 and 14.

First, in step S1401, the crack 3c is linearly extended to the second bore hole 2d based on the representative depth, strike and inclination of the crack 3c. Next, in step S1402, the depth of the intersection Pc between the extended virtual crack 3c'and the central axis of the second bore hole 2d is calculated. Next, in step S1403, the depth difference (apparent depth difference) Dc between the intersection Pc and the crack 3d is calculated.

Steps S1401, S1402, and S1403 are also performed on the crack 3d in the second bore hole 2d. It is determined in step S1404 whether steps S1401, S1402 and S1403 have been performed on both cracks 3c and 3d. By executing steps S1401, S1402, and S1403 for the crack 3d, the depth of the intersection Pd between the virtual crack 3d'and the central axis of the first bore hole 2c is calculated, and the depth difference between the intersection Pd and the crack 3c (apparent). Depth difference) Dd is calculated.

Next, in step S1405, the average value of the two apparent depth differences Dc and Dd is calculated. Next, in step S1406, the average value of the apparent depth differences Dc and Dd is divided by the distance between the cracks 3c and 3d. From the above, a normalized apparent depth difference can be obtained.

In the present embodiment, the average values of the depth differences Dc and Dd are calculated as the apparent depth difference, but the apparent depth difference may be calculated by the so-called inter-plane distance. The method of calculating the inter-plane distance will be specifically described with reference to FIG. First, the crack 3c is extended in a plane based on the representative depth, strike and inclination of the crack 3c. Next, the perpendicular line NLd is extended from the center of the crack 3d to the extended virtual crack plane 3c ″, and the length Ld of the perpendicular line NLd is calculated. Similarly, the perpendicular line NLc is extended from the center of the crack 3c to the virtual crack plane 3d ″ which is a planar extension of the crack 3d, and the length Lc of the perpendicular line NLc is calculated. Calculate the average value of the lengths Lc and Ld of the perpendicular lines NLc and NLd, and divide by the distance between the cracks 3c and 3d. From the above, the normalized face-to-face distance can be obtained.

Next, a case where the intersection angle between the unit normal vector of the crack 3c and the unit normal vector of the crack 3d is calculated as an index will be described. The cracks usually extend substantially linearly in the foundation ground 1 (see FIG. 1). Therefore, the closer the normal vectors of the cracks 3c and 3d are, that is, the closer the intersection angle of the unit normal vectors of the cracks 3c and 3d is to 0, the higher the possibility that the cracks 3c and 3d are continuous. .. In other words, it is possible to determine the continuity of the cracks 3c and 3d by using the intersection angle of the unit normal vectors of the cracks 3c and 3d as an index. Hereinafter, the case of calculating the intersection angle of the unit normal vectors between the cracks 3c and 3d will be specifically described with reference to FIGS. 13 and 15.

First, in step S1501, the equation of a plane of the crack 3c is calculated based on the strike and inclination of the crack 3c. Next, in step S1502, the unit normal vector Vc in the crack 3c is calculated from the equation of a plane.

Steps S1501 and S1502 are also performed on the crack 3d. Whether steps S1501 and S1502 are performed on both cracks 3c and 3d is determined in step S1503. By executing steps S1501 and S1502 on the crack 3d, the unit normal vector Vd in the crack 3d is calculated.

Next, in step S1504, the intersection angle of the unit normal vectors Vc and Vd between the cracks 3c and 3d is calculated. From the above, the intersection angle of the unit normal vectors Vc and Vd of the cracks 3c and 3d can be obtained.

Next, a case where the width difference between the cracks 3c and 3d is calculated as an index will be described. In one continuous crack, the width at the first bore hole 2c and the width at the second bore hole 2d are usually substantially the same. Therefore, the smaller the width difference between the cracks 3c and 3d, the higher the possibility that the cracks 3c and 3d are continuous. In other words, it is possible to determine the continuity between the cracks 3c and 3d by using the width difference between the cracks 3c and 3d as an index. Hereinafter, the case of calculating the width difference between the cracks 3c and 3d will be specifically described with reference to FIGS. 13 and 16.

First, in step S1601, the representative width WNc of the crack 3c and the representative width WNd of the crack 3d are acquired. Next, in S1602, the larger width of the representative width WNc and the representative width WNd is divided by the smaller width. From the above, the relative width difference between the cracks 3c and 3d can be obtained.

The representative widths WNc and WNd acquired in step S1601 are corrected by the inclination φ of the cracks 3c and 3d, respectively. Therefore, it is possible to obtain a width difference that is not affected by the inclination φ of the cracks 3c and 3d, and the accuracy of determining the crack continuity, which will be described later, is improved.

Next, a case where the color information difference between the cracks 3c and 3d is calculated as an index will be described. In one continuous crack, the color information of the crack in the first bore hole 2c and the color information of the crack in the second bore hole 2d are usually substantially the same. Therefore, the smaller the color information difference between the cracks 3c and 3d, the higher the possibility that the cracks 3c and 3d are continuous. In other words, it is possible to determine the continuity between the cracks 3c and 3d by using the color information difference between the cracks 3c and 3d as an index. Hereinafter, the case of calculating the color information difference between the cracks 3c and 3d will be specifically described with reference to FIGS. 13 and 17.

First, in step S1701, the color information (L * value, a * value, and b * value) of the cracks 3c and 3d is acquired. Next, in step S1702, the larger L * value of the L * value of the crack 3c and the L * value of the crack 3d is compared with the smaller L * value, and the difference between the L * values is calculated. do. Similarly, for the a * value and the b * value, the difference between the a * value and the b * value is calculated in steps S1503 and S1504, respectively. Next, in S1505, the average value of the differences between the L * value, the a * value, and the b * value is calculated. From the above, the color information difference between the cracks 3c and 3d can be obtained.

When the color information difference is a relative difference, not only a positive value but also a negative value may be taken, so convenience, relative difference, and absolute difference may be selected.

Next, as an index, a case of calculating the ludion value difference between the cracks 3c and 3d will be described. The Lugeon value is an index showing the ease of water passage when the ground is under the action of high water pressure, and the higher the Lugeon value, the easier it is for water to pass through (higher permeability). The ludion value is determined by the so-called luzion test. The luzion test is a test in which a water pressure of 1 [MPa] is applied to a bore hole formed in the ground, and the amount of water that permeates the ground in one minute while a water pressure of 1 [MPa] is applied is the luzion value. .. The luzion test is performed at each predetermined depth of the borehole (for example, every 1 m), and the ludion value is obtained at each predetermined depth of the borehole. The luzion value obtained by the luzion test is taken into the crack continuity determination system 1000 by the rudion value capturing unit 32 (see FIG. 12).

In one continuous crack, the rudion value in the first bore hole 2c and the rudion value in the second bore hole 2d are usually substantially the same. Therefore, the smaller the difference in the rudion value between the cracks 3c and 3d, the higher the possibility that the cracks 3c and 3d are continuous. In other words, it is possible to determine the continuity between the cracks 3c and 3d by using the difference in the rudion values between the cracks 3c and 3d as an index. Hereinafter, the case of calculating the luzion value difference between the cracks 3c and 3d will be specifically described with reference to FIG.

First, in step S1801, the representative depths of the cracks 3c and 3d are acquired. Next, in step S1802, the rudion values at the representative depths of the cracks 3c and 3d are acquired. Next, in step S1803, the rudion value of the crack 3c and the rudion value of the crack 3d are compared, and the larger rudion value is divided by the smaller rudion value. As a result, the relative difference between the luzion values is calculated.

From the above, the apparent depth difference between the cracks 3c and 3d, the intersection angle of the normal vector, the width difference, the color information difference, and the ludion value difference are calculated as indexes.

Next, with reference to FIG. 19, regarding the process of determining the continuity of the cracks using the apparent depth difference between the cracks 3c and 3d, the intersection angle of the normal vectors, the width difference, the color information difference, and the luzion value difference. I will explain. The process of determining continuity is performed by the continuity determination unit 34 (see FIG. 12).

First, in step S1901, a cumulative relative frequency distribution of the apparent depth difference between the cracks 3c and 3d, the intersection angle of the normal vectors, the width difference, the color information difference, and the luzion value difference is created. Next, in step S1902, the cumulative degree is calculated for each index of each of the cracks 3c and 3d. Next, in step S1903, the weighted average value of the cumulative degree is calculated and acquired as the continuity determination score.

Next, in step S1904, the continuity between the cracks 3c and 3d is determined based on the continuity determination score. Specifically, when the continuity determination score is equal to or higher than the predetermined continuity determination threshold value, it is determined that the cracks 3c and 3d are continuous, and when the continuity determination score is less than the continuity determination threshold value, it is determined. It is determined that the cracks 3c and 3d are not continuous.

As a result, the process of determining the continuity of the cracks 3c and 3d is completed.

The determination result output unit 35 (see FIG. 12) displays the result of determining the continuity of the cracks on a medium such as a monitor or paper. FIG. 20 shows an example of display. In the example shown in FIG. 20, the results of determining the continuity of the cracks 3e1, 3e2, 3e3, 3e4, 3e5 detected in the bore hole 2e and the cracks 3f1, 3f2, 3f3, 3f4 detected in the bore hole 2f are displayed. .. Specifically, the results of determining that the cracks 3e2, 3f3 are continuous and that the cracks 3e1, 3e3, 3e4, 3e5, 3f1, 3f2, 3f4 are not continuous with any other cracks are displayed. doing.

First, the indications relating to the cracks 3e1, 3e3, 3e4, 3e5, 3f1, 3f2, 3f4 that are determined to be non-continuous will be described on behalf of the cracks 3e1. The determination result output unit 35 virtualizes that a disk-shaped crack exists at a representative depth of the crack 3e1 as a result of the continuity determination regarding the crack 3e1, and displays the disk-shaped virtual crack 4e. The center, strike and slope of the virtual crack 4e are set to coincide with the center, strike and slope of the crack 3e1. The radius of the virtual crack 4e is set so that the outer circumference of the virtual crack 4e exceeds the inner wall of the bore hole 2e and does not reach the bore hole 2f.

The results of the continuity determination for the cracks 3e3, 3e4, 3e5, 3f1, 3f2, 3f4 are also displayed in the same manner as the virtual crack 4e.

Next, the display regarding the cracks 3e2, 3f3 determined to be continuous with each other will be described. The determination result output unit 35 virtualizes that a disk-shaped crack extending from the bore hole 2e to the bore hole 2f exists as a result of the continuity determination regarding the cracks 3e2 and 3f3, and displays the disk-shaped virtual crack 4ef. The center of the virtual crack 4ef is set at the midpoint of the line segment connecting the center of the crack 3e2 and the center of the crack 3f3. The strike and slope of the virtual crack 4ef are set to the average of the strike and slope of the crack 3e2 and the crack 3f3, respectively. The radius of the virtual crack 4ef is set so that the outer circumference of the virtual crack 4ef exceeds the bore holes 2e and 2f and does not reach other bore holes (not shown).

As described above, with respect to the cracks 3e2 and 3f3 determined to be continuous with each other, the virtual crack 4ef extending from the bore hole 2e to the bore hole 2f is displayed, so that the size and position of the continuous cracks can be easily grasped.

Although not shown, when it is determined that three or more cracks detected in three or more boreholes are continuous, a disk-shaped virtual crack is displayed so as to include these cracks. The virtual crack is not limited to a disk shape and may be displayed as a rectangular curved surface.

As described above, in the crack continuity determination system 1000, the continuity between cracks detected by the crack detection device 100 is determined by the processing of the computer 20. Therefore, the continuity of the cracks in the bore hole 2 can be detected quickly and with a constant accuracy, and the cracks in the foundation ground 1 (see FIG. 1) can be estimated. This makes it possible to more reliably determine the grouting specifications so as to close the cracks in the foundation ground 1.

For example, in the example shown in FIG. 20, it is possible to propose a grouting specification in which a crack corresponding to a virtual crack 4ef is closed by forming a new bore hole between the bore holes 2e and 2f and injecting grout. become. As a result, the crack corresponding to the highly permeable virtual crack 4ef presumed to exist between the bore holes 2e and 2f can be closed by grout, and the water impermeability of the foundation ground 1 can be enhanced.

According to the above embodiment, the following effects are exhibited.

In the crack detection device 100, a sinusoidal waveform is extracted from the developed image based on the crack, and the strike and inclination of the crack in the inner wall of the bore hole 2 are acquired from the sinusoidal waveform. Therefore, the crack can be detected quickly and with a constant accuracy, and the strike and inclination of the crack can be obtained.

Further, in the crack continuity determination system 1000, the continuity between cracks is determined based on an index for determining the continuity between cracks. Therefore, the continuity of cracks can be determined quickly and with constant accuracy. Thereby, the specifications of the grouting can be easily determined.

Further, in the crack continuity determination system 1000, the apparent depth difference and the intersection of normal vectors calculated based on the strike and inclination acquired by the crack detection device 100 are used as indexes for determining the continuity between cracks. Angle is included. Since the strike and inclination of the crack can be detected quickly and with constant accuracy, the apparent depth difference and the intersection angle of the normal vector can be calculated quickly and with constant accuracy. Therefore, the continuity of cracks can be quickly determined and the accuracy thereof can be improved.

Further, in the crack continuity determination system 1000, the width difference calculated based on the width of the crack acquired by the crack width acquisition unit 24 is included in the index. Since the width of the crack can be detected quickly and with a constant accuracy by the crack detection device 100, the width difference can be calculated quickly and with a constant accuracy. Therefore, the continuity of cracks can be quickly determined and the accuracy thereof can be improved.

Further, in the crack continuity determination system 1000, the width of the crack acquired by the crack width acquisition unit 24 is a width corrected by using the inclination acquired by the strike and dip symbol acquisition unit 23. Therefore, it is possible to obtain a width difference that is not affected by the inclination of the crack, and the accuracy of determining the continuity of the crack is improved.

Further, in the crack continuity determination system 1000, the difference in the color information of the cracks acquired by the crack color information acquisition unit 25 is included in the index. Since the color information of the crack can be detected quickly and with a constant accuracy by the crack detection device 100, the difference in the color information can be calculated quickly and with a constant accuracy. Therefore, the continuity of cracks can be quickly determined and the accuracy thereof can be improved.

Further, in the crack continuity determination system 1000, the difference in the rudion value at the depth of the crack is included in the index. Therefore, continuous and highly permeable cracks can be easily and highly accurately determined.

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. No.

The crack continuity determination system 1000 determines the continuity of cracks by using all of the apparent depth difference between cracks, the intersection angle of normal vectors, the width difference, the color information difference, and the luzion value difference. The continuity of cracks may be determined based on at least one of these indicators.

1 ... Ground 2,2c, 2d, 2e, 2f ... Bore hole 3,3a, 3b, 3c, 3d, 3e, 3ec, 3ed, 3f ... Crack 10 ... Bore hole camera (image creation unit)
22 ... Rhagades extraction unit 23 ... Strike and dip symbol acquisition unit 24 ... Rhagades width acquisition unit 25 ... Rhagades color information acquisition unit 33 ... Index calculation unit 34 ... Continuity judgment unit 100 ...・ Crack detection device 1000 ・ ・ ・ Crack continuity judgment system

Claims (12)

The developed image obtained by photographing the inner walls of the first and second bore holes formed on the ground is analyzed to extract a sine waveform based on a crack from the developed image, and the first sine waveform is extracted from the extracted sine waveform. A crack detection device that detects the cracks in the first and second bore holes and acquires the strike and inclination of the cracks.
An index calculation unit that calculates an index for determining the continuity of the cracks in the first and second bore holes detected by the crack detection device, and
A crack continuity determination system including a continuity determination unit for determining continuity between cracks in the first and second bore holes based on the index calculated by the index calculation unit. The index is a virtual crack formed in the second bore hole and the second bore hole when the crack in the first bore hole is extended to the second bore hole based on the strike and inclination of the crack in the first bore hole. The crack continuity determination system according to claim 1, which includes a depth difference from the crack. Claim 1 includes the intersection angle of the normal vector obtained from the strike and inclination of the crack in the first bore hole and the normal vector obtained from the strike and inclination of the crack in the second bore hole. Or the crack continuity determination system according to 2. The crack detection device further includes a crack width acquisition unit that analyzes the developed image and acquires the width of the crack.
The crack continuity determination system according to any one of claims 1 to 3, wherein the index includes a difference between the width of the crack in the first bore hole and the width of the crack in the second bore hole. The crack continuity determination system according to claim 4, wherein the width of the crack in the first bore hole and the width of the crack in the second bore hole are widths corrected by using the inclination. The crack detection device further includes a crack color information acquisition unit that analyzes the developed image and acquires color information of the crack.
The crack continuity determination system according to any one of claims 1 to 5, wherein the index includes a difference between the color information of the crack in the first bore hole and the color information of the crack in the second bore hole. The index according to any one of claims 1 to 6, which includes a difference between a rudion value at the depth of the crack in the first bore hole and a rudion value at the depth of the crack in the second bore hole. Crack continuity judgment system. The developed image obtained by photographing the inner walls of the first and second bore holes formed on the ground was analyzed, and a sine waveform based on the crack was extracted from the developed image.
From the sinusoidal waveform, the cracks in the first and second bore holes are detected, and the strike and inclination of the cracks are obtained.
An index for determining the continuity of the cracks in the detected first and second bore holes was calculated.
A crack continuity determination method for determining the continuity between cracks in the first and second bore holes based on the calculated index. The developed image obtained by photographing the inner walls of the first and second bore holes formed on the ground was analyzed, and a sine waveform based on the crack was extracted from the developed image.
From the sinusoidal waveform, the cracks in the first and second bore holes are detected, and the strike and inclination of the cracks are obtained.
An index for determining the continuity of the cracks in the detected first and second bore holes was calculated.
A crack continuity determination program for causing a computer to execute a process of determining the continuity of the cracks in the first and second bore holes based on the calculated index. A sine waveform extraction unit that analyzes a developed image obtained by photographing the inner wall of a bore hole formed in the ground and extracts a sine waveform based on a crack from the developed image.
A strike and dip symbol acquisition unit that detects the crack in the borehole and acquires the strike and dip of the crack from the sine waveform based on the crack extracted by the sine waveform extraction unit is provided.
The sine waveform extraction unit superimposes a plurality of tentative sine waveforms on the developed image, and sets a representative value of brightness in a plurality of pixels through which each of the plurality of tentative sine waveforms passes for each of the plurality of tentative sine waveforms. Calculated, and based on the calculated representative value , one of the plurality of provisional sine waveforms is extracted as a sine waveform based on the crack.
Crack detector. A sine waveform extraction step of analyzing a developed image obtained by photographing the inner wall of a bore hole formed in the ground and extracting a sine waveform based on a crack from the developed image, and a sine waveform extraction step.
A strike and dip symbol acquisition step for detecting the crack in the bore hole and acquiring the strike and dip of the crack from the sinusoidal waveform based on the crack is provided.
In the sine waveform extraction step, a plurality of tentative sine waveforms are superimposed on the developed image, and a representative value of brightness in a plurality of pixels through which each of the plurality of tentative sine waveforms passes is set for each of the plurality of tentative sine waveforms. Calculated, and based on the calculated representative value , one of the plurality of provisional sine waveforms is extracted as a sine waveform based on the crack.
Crack detection method. A sine waveform extraction process that analyzes the developed image obtained by photographing the inner wall of the bore hole formed in the ground and extracts a sine waveform based on the crack from the developed image.
A strike and dip symbol acquisition process for detecting the crack in the borehole and acquiring the strike and dip of the crack from the sinusoidal waveform based on the crack.
Is a crack detection program that allows a computer to execute
In the sine waveform extraction process, a plurality of tentative sine waveforms are superimposed on the developed image, and a representative value of brightness in a plurality of pixels through which each of the plurality of tentative sine waveforms passes is set for each of the plurality of tentative sine waveforms. A crack detection program for causing the computer to execute a process of calculating and extracting one of the plurality of provisional sine waveforms as a sine waveform based on the crack based on the calculated representative value.

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