JP7685912B2 - Embankment material quality control system and embankment material quality control method - Google Patents

Description

The present invention relates to a quality control system for embankment materials and a quality control method for embankment materials.

Until now, quality control of soil used as embankment material has been carried out based on visual inspection and the results of grain size tests specified by JIS.
However, with a visual inspection, it was only possible to distinguish the general properties of the soil (grain size, color).
On the other hand, particle size testing requires large-scale equipment (drying ovens, etc.) and takes at least two days to complete the measurement.
In recent years, a method has been proposed to measure the particle size distribution of soil by photographing the soil to be used as material with a CMOS camera and analyzing the obtained soil image (see, for example, Non-Patent Document 1 and Patent Documents 1 and 2).

Takehisa Shiiba et al., Development and Application Examples of Embankment Material Management System Using ICT, Foundation Works, Japan Civil Engineering Research Institute, November 2020, pp. 88-91

Patent No. 6243640 JP 2016-200518 A

However, the method described in Non-Patent Document 1 measures the particle size distribution on a vehicle that transports soil, and still requires large-scale equipment. In addition, this method only targets gravelly soil with a relatively large particle size (20 mm or more).
In addition, the methods described in Patent Documents 1 and 2 are for measuring the particle size distribution of soil used in dams, etc., and still require large-scale facilities such as the use of belt conveyors to transport the soil. In addition, these methods also only target gravelly soil with a relatively large particle size (5 mm or more).
For this reason, conventional methods such as those described in Non-Patent Document 1 and Patent Documents 1 and 2 can be difficult to use in embankment construction sites, etc., where it is difficult to install large-scale equipment.
In addition, embankments are sometimes constructed using sandy soil with a relatively small grain size, but conventional methods were not always able to measure the grain size distribution of such sandy soil.

The present invention was made in consideration of the above problems, and aims to make it possible to easily and quickly measure the particle size distribution of soil used as material at embankment construction sites.

In order to solve the above problem, the invention according to claim 1 comprises:
A fill material quality control system, comprising:
A portable housing having an opening on an upper surface;
A first photographing means is provided in the housing and photographs a first soil having a relatively large grain size that is poured through the opening and falling through the housing;
A second photographing means is provided in the housing and photographs a second soil having a relatively small grain size placed in the housing or the first soil;
An imaging device comprising:
a measuring device that measures the particle size distribution of the first soil based on an image of the first soil obtained by the first photographing means, and measures the particle size distribution of the second soil based on an image of the second soil obtained by the second photographing means;
The present invention is characterized by comprising:

The invention according to claim 2 is as follows:
The embankment material quality control system according to claim 1,
a camera attached to the housing and switchable between a state in which the lens is oriented horizontally and a state in which the lens is oriented downward;
The camera with the lens facing horizontally serves as the first photographing means, and the camera with the lens facing downward serves as the second photographing means.

The invention according to claim 3 is as follows:
The embankment material quality control system according to claim 1 or 2,
The measuring device is characterized in that it also measures the color of the first soil or the color of the second soil based on the image of the first soil or the image of the second soil obtained by the second photographing means.

The invention according to claim 4 is as follows:
The embankment material quality control system according to any one of claims 1 to 3,
The present invention is characterized in that it comprises a dispersion part having an inclined surface provided above the opening and sloping downward in a direction away from the first photographing means, and at least one protrusion provided on the inclined surface for dispersing the first soil sliding down the inclined surface in a direction along the inclined surface and perpendicular to the direction in which the first soil slides down.

The invention according to claim 5 is as follows:
A method for controlling quality of embankment materials, comprising:
an installation process for installing an imaging device at a construction site of an embankment, the imaging device comprising: a portable housing having an opening on an upper surface; a first imaging means for imaging a first soil having a relatively large grain size that is poured in through the opening and falling through the housing; and a second imaging means for imaging a second soil having a relatively small grain size that is placed in the housing;
a sample supply step of introducing a first sample extracted from the first soil into the opening when the soil to be used as the material is the first soil, and placing a second sample extracted from the second soil in the housing when the soil to be used as the material is the second soil;
an imaging step of imaging the first sample falling inside the housing by the first imaging means or imaging the second sample placed inside the housing by the second imaging means;
A measuring device measures the particle size distribution of the first soil based on the image of the first soil obtained by the first photographing means, and measures the particle size distribution of the second soil based on the image of the second soil obtained by the second photographing means, a measuring step of measuring the particle size distribution of the first soil based on the image of the first sample obtained in the photographing step, or measuring the particle size distribution of the second soil based on the image of the second sample;
a judgment step of judging whether the first soil or the second soil is suitable for construction based on the particle size distribution obtained in the measurement step;
The present invention is characterized by having the following.

According to the present invention, the particle size distribution of soil used as material at an embankment construction site can be easily and quickly measured.

FIG. 1 is a side view showing an example of a quality control system for embankment materials according to an embodiment of the present invention. FIG. 2 is a rear view showing an example of an imaging device provided in the system. FIG. 11 is a front view showing the upper part of the photographing device when the first soil is being poured in. FIG. 13 is a schematic diagram illustrating a second method for preparing soil for measuring particle size distribution. FIG. 13 is a perspective view showing the inside of the photographing device when photographing a second soil for measuring particle size distribution. 1 is a perspective view showing the inside of the photographing device when photographing a first soil or a second soil to measure color. FIG. 1 is a graph showing the particle size distribution of a first sample obtained by a particle size test, and a graph showing the particle size distribution of a first sample obtained by a fill material quality control system. 1 is a graph showing the particle size distribution of a second sample obtained by a particle size test, and a graph showing the particle size distribution of a second sample obtained by a fill material quality control system. 1 is a graph showing the colors of the first to third samples obtained using the fill material quality control system.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
However, the technical scope of the present invention is not limited to the following embodiments and examples shown in the drawings.

<1. Embankment material quality control system>
First, a banking material quality control system (hereinafter, system 100) according to an embodiment of the present invention will be described.
FIG. 1 is a side view showing an example of a system 100, FIG. 2 is a rear view showing an example of a photographing device provided in the system 100, and FIG. 3 is a front view showing the upper part of the photographing device when the first soil is being added.

The system 100 includes, for example, an imaging device 1 and a measuring device 2 as shown in FIG.
The system 100 according to this embodiment further includes a power supply device 3 .

(Photographing device)
The photographing device 1 includes a housing 11 and a camera 12 .
In this embodiment, the photographing device 1 further includes a dispersion unit 13 , a first illumination unit 14 , a second illumination unit 15 , and a tray 16 .

The housing 11 is of a portable type and has an opening 11a on the top surface.
The housing 11 according to this embodiment has a vertically long rectangular parallelepiped shape.
As shown in FIG. 2, the housing 11 according to this embodiment has a second opening 11b on the rear surface.
Moreover, the housing 11 according to this embodiment includes a camera support portion 11c.
As shown in FIG. 1, the camera support portion 11c is rod-shaped.
One end of the camera support portion 11c is supported by a shaft rod 11d that extends in the left-right direction at the lower end of the second opening 11b, and is capable of rotating around the shaft rod 11d.

The housing 11 does not necessarily have to be box-shaped as long as it is configured to support the camera 12.

The dispersion section 13 is provided above the opening 11a of the housing 11 and disperses the first soil _S1 that is poured into the opening 11a.
The first soil _S1 is a relatively large-grained soil intended to be used as a filling material.
The first soil _S1 according to this embodiment is gravel soil containing gravel having a grain size in the range of 2 to 75 mm.
The dispersion portion 13 according to this embodiment has an inclined surface 13a and at least one protrusion 13b.
The distribution section 13 according to this embodiment further includes a hopper 13c.

The inclined surface 13 a is provided above the opening 11 a and is inclined downward in a direction away from the camera 12 .
The inclined surface 13a according to this embodiment is inclined downward toward the front.
The protrusions 13b are provided on the inclined surface 13a and disperse the first soil _S1 sliding down the inclined surface 13a in a direction along the inclined surface 13a and perpendicular to the direction of the first soil S1 sliding down the inclined surface 13a.
As described above, since the inclined surface 13a according to this embodiment is inclined downward toward the front, the protrusions 13b according to this embodiment disperse the first soil _S1 in the left-right direction.
The hopper 13c is provided above the upper part of the inclined surface 13a and is designed to drop the input first soil _S1 onto the upper part of the inclined surface 13a.
By the dispersion section 13 configured in this manner, the first soil _S1 put into the hopper 13c falls inside the housing 11 in a dispersed state in the left and right directions.

As shown in FIG. 1, the dispersion unit 13 according to this embodiment is configured to be movable in the horizontal direction (front-rear direction) (the width of the opening 11a of the housing 11 in the front-rear direction can be adjusted).
In this way, when the grain size of the first soil _S1 to be added is relatively large, the dispersion section 13 can be lowered backward (opening the opening 11a of the housing 11 wide) to prevent the first soil _S1 from getting stuck between the opening 11a and the dispersion section 13.
Furthermore, by moving the dispersion portion 13 forward (closer to the front of the housing 11), the first soil _S1 falling will hit the rear front surface of the housing 11, and the first soil _S1 will be dispersed more.

The camera 12 is attached to the housing 11, and as shown in FIG. 1, is switchable between a state in which the lens 12a faces horizontally and a state in which the lens 12a faces downward.
The camera 12 according to this embodiment is fixed to the camera support portion 11c of the housing 11, and is capable of the above-mentioned switching by rotating together with the camera support portion 11c.
The camera 12, with its lens oriented horizontally, can photograph the first soil _S1 that has been inserted through the opening 11a and is falling through the housing 11.
On the other hand, the camera 12 with its lens facing downward can photograph the second soil _S2 or the first soil _S1 placed in the housing 11.
The second soil _S2 is a relatively fine-grained soil intended to be used as fill material.
The second soil _S2 according to this embodiment is a sandy soil containing sand having a grain size of 2 mm or less.
That is, the camera 12 with the lens facing horizontally serves as a first imaging means, and the camera 12 with the lens 12a facing downward serves as a second imaging means.

In this way, by having one camera 12 serve as both the first photographing means and the second photographing means, the housing 11 can be made smaller than when a camera with a lens facing horizontally and a camera with a lens facing downward are provided separately.
In addition, the camera 12 according to the present embodiment is capable of repeating the photographing several times in a short period of time (for example, 14 times per second), so that the camera 12 according to the present embodiment can photograph the first soil S1 falling without missing any of the first soil _S1 .
Moreover, the camera 12 according to this embodiment is configured to transmit data of the captured image to the measuring device 2 via a communication network N (wired or wireless).

The first illumination unit 14 is provided inside the housing 11 and emits light toward the first imaging means (rearward).
The first illumination unit 14 according to this embodiment is provided on the front rear surface of the housing 11 so as to face rearward.
Moreover, the first illumination unit 14 according to this embodiment emits white light.
Moreover, the first illumination unit 14 according to this embodiment is also capable of illuminating downward.

The second illumination unit 15 is provided inside the housing 11 and emits light toward the second imaging means (upward).
The second illumination unit 15 according to this embodiment is provided on the upper surface of the bottom of the housing 11 so as to face upward.
Moreover, the second illumination unit 15 according to this embodiment is capable of placing the first soil _S1 or the second soil _S2 on its upper surface.

The tray 16 is provided inside the housing 11 between the downward-facing camera 12 and the second lighting unit 15 (for example, placed on the upper surface of the second lighting unit 15), and serves to receive the first soil _S1 that falls inside the housing 11.
The tray 16 is removable from the housing 11 and is removed when photographing the second soil _S2 placed on the second illumination unit 15 for measuring the particle size distribution.

The photographing device 1 may be provided with a camera serving as the first photographing means and a camera serving as the second photographing means separately.
In addition, the photographing device 1 may be provided with a platform for placing the second soil _S2 , separate from the second illumination unit 15.

(Measuring device)
The measuring device 2 according to this embodiment is configured as a PC on which a program is installed.
Furthermore, the measuring device 2 according to this embodiment is configured to receive image data from the camera 12 via a communication network.
The measuring device 2 then measures the particle size distribution of the first soil S1 based on the image of the first soil _S1 obtained by the first photographing means, and measures the particle size distribution of the second soil _S2 based on the image of the second soil _S2 obtained by the second photographing means _.
The measuring device 2 according to this embodiment analyzes the images of the first and second soil _S2 and calculates the particle size distribution of the soil.
The image analysis for measuring the soil particle size distribution can be carried out using conventional techniques such as those described in the above-mentioned Non-Patent Document 1, Patent Documents 1 and 2, and the like.

In addition, the measuring device 2 according to this embodiment also measures the color of the first soil _S1 or the color of the second soil _S2 based on an image of the first soil _S1 or an image of the second soil _S2 obtained by the second photographing means.
The measuring device 2 according to this embodiment analyzes the images of the first and second soils _S2 and calculates the chromaticity and saturation of the soils, respectively.
Various conventionally known techniques can be used to analyze the images to measure the color and saturation of the soil.

Furthermore, the measurement device 2 according to this embodiment is adapted to display the measurement results.
The measuring device 2 may be configured as a dedicated device.
Furthermore, the measurement device 2 may be configured to notify the measurement results by a method other than display (for example, by voice).

(power supply)
The power supply device 3 supplies power to the first and second lighting units 14 and 15 .
The power supply device 3 may be configured to supply power to at least one of the camera 12 and the measuring device 2 .

(Modification)
The system 100 may be an integrated system of at least two of the imaging device 1, the measuring device 2, and the power supply device 3.
Furthermore, in the system 100, the measuring device 2 may be disposed at a location away from the installation location (construction site) of the imaging device 1.
Furthermore, in the system 100, the camera 12 and the measuring device 2 may not have a communication function. The camera 12 may write image data to a medium, and the measuring device 2 may read the data from the medium.
Furthermore, the system 100 may be configured to receive power from a household power source or the like. In this case, the power supply device 3 is not necessary.

<2. Quality control method for embankment materials>
Next, a method for controlling the quality of embankment materials (hereinafter, the control method) using the above-mentioned system 100 will be described.
Figure 4 is a schematic diagram explaining a method of preparing the second soil for measuring its particle size distribution, Figure 5 is a perspective view showing the inside of the photographing device 1 when photographing the second soil for measuring its particle size distribution, and Figure 6 is a perspective view showing the inside of the photographing device 1 when photographing the first soil or the second soil for measuring its color.

The management method includes an installation step, a sample supplying step, an imaging step, a measurement step, and a determination step.
Furthermore, in the management method according to this embodiment, the sample supplying step, the photographing step, the measuring step, and the judging step are repeated periodically (for example, every few days).

(Installation process)
In the first installation step, at least the image capturing device 1 of the system 100 is installed at the embankment construction site.
The photographing device 1 is of a portable size and can therefore be installed even at construction sites where it is difficult to install large-scale equipment.
In the installation process, the measuring device 2 and the power supply device 3 are connected to the imaging device 1 .

(Sample supply process/photography process)
After the imaging device 1 is installed, the process proceeds to a sample supplying step and an imaging step.
In this sample supplying process, the contents to be carried out vary depending on the soil material and the measurement contents.
For example, when the soil material is a first soil _S1 and the measurement content is particle size distribution, the first illumination unit 14 is turned on and a first sample _S1 extracted from the first soil _S1 is placed into the opening 11a (the dispersion unit 13 above it).
At this time, the position of the dispersion section 13 in the front-rear direction is adjusted in advance depending on the apparent grain size of the sample and the degree of agglomeration.
Then, the first sample _S1 falling inside the housing 11 is photographed by the first photographing means (the camera 12 with the lens 12a facing horizontally).
In the sample supplying step according to this embodiment, the first sample _S1 is repeatedly photographed at high speed.

On the other hand, when the soil material is the second soil _S2 and the measurement content is particle size distribution, the tray 16 is removed from the housing 11, the second illumination unit 15 is turned on, and the second sample _S2 extracted from the second soil _S2 is placed inside the housing 11 (on the upper surface of the second illumination unit 15).
In the sample supplying step according to the present embodiment, for example, as shown in FIG. 4(a), the second sample _S2 is placed in a small dish D (e.g., a petri dish) with at least a transparent bottom, and then water W is poured into the dish D to wet the sample. Then, as shown in FIG. 4(b), the fine components C of the second sample _S2 float on the surface of the water W, and the fine components C are removed. Then, as shown in FIG. 4(c), the water W is removed from the dish D. Then, as shown in FIG. 5, for example, the second sample _S2 from which the fine components C have been removed is placed on the upper surface of the second illumination unit 15 in a dispersed state (a state in which the outlines of individual particles are visible).
At that time, the second sample _S2 may be placed directly on the second illumination unit 15, or the entire dish D may be placed thereon.
Thereafter, the second sample _S2 placed in the housing 11 is photographed by the second photographing means (camera 12 with lens 12a facing downward).

In addition, when the soil material is the first soil _S1 or the second soil _S2 and the measurement content is color, the first lighting unit 14 is turned on and the first soil _S1 or the second soil _S2 is spread over the entire upper surface of the second lighting unit 15, for example, as shown in FIG. 6 (so that the upper surface of the second lighting unit 15 is not visible due to the soil).
In this case, the first sample _S1 or the second sample _S2 may be directly spread on the second illumination unit 15, or may be spread on a large dish (e.g., a receiving dish 16) placed on the second illumination unit 15.
Thereafter, the first sample S ₁ or the second sample S ₂ placed in the housing 11 is photographed by the second photographing means.
As described above, the first lighting unit 14 also illuminates downward, so that during photography, the first soil _S1 or the second soil _S2 spread out on the second lighting unit 15 is illuminated by the white light emitted by the first lighting unit 14.

(Measurement process)
After photographing the soil, the measurement process begins.
In this measurement step, the measuring device 2 measures the particle size distribution of the first soil _S1 based on the image of the first sample _S1 obtained in the photographing step, or measures the particle size distribution of the second soil _S2 based on the image of the second sample _S2 .
In the measurement process according to this embodiment, after measuring the particle size distribution, the measuring device 2 displays the measurement results (graphs showing the particle size distribution (see FIGS. 7 and 8 ), classification of the soil according to particle size (coarse gravel, medium gravel, fine gravel, coarse sand, medium sand, fine sand, etc.), the difference from the previous measurement result, etc.).

In addition, in the measurement process according to this embodiment, the measuring device 2 also measures the color of the first soil _S1 or the color of the second soil _S2 based on an image of the first soil _S1 or the second soil _S2 obtained by the second photographing means.
As described above, when photographing, the first soil _S1 or the second soil _S2 spread on the second illumination unit 15 is illuminated with white light emitted by the first illumination unit _14. By measuring the color using an image of the first sample _S1 or the second sample S2 obtained by photographing the first sample _S1 or the second sample _S2 illuminated with this white light, it is possible to obtain measurement results similar to those obtained when the first sample _S1 or the second sample _S2 is wet (even if the water content is high). As a result, a step of drying the first sample _S1 or the second sample _S2 before photographing is not required.
After measuring the color, the measuring device 2 displays the measurement results (a graph showing the color (see Figure 9), the classification of the soil according to the color (gravel soil, sandy soil, clayey soil, etc.), the difference from the previous measurement result, etc.).

(Judgment process)
After measuring the soil particle size distribution and color, the process moves to the judgment step.
In this judgment step, it is judged whether the first soil S ₁ or the second soil S ₂ is suitable for construction based on the particle size distribution obtained in the measurement step.
In addition, in the judgment step according to this embodiment, it is judged whether the first soil S ₁ or the second soil S ₂ is suitable for construction based on the particle size distribution and color obtained in the measurement step.
Whether or not soil is suitable for construction is determined, for example, by checking whether the differences between the particle size distribution, color, and saturation of the soil obtained this time and the initial particle size distribution, color, and saturation of the soil obtained through tests at the beginning of construction are within specified ranges.
This determination may be made by the measuring device 2 or by a person who views the measurement results.

If it is determined in this determination process that the first soil S ₁ or the second soil S ₂ is not suitable for construction, for example, the soil is returned to its original location.
On the other hand, if it is determined in this judgment process that the first soil S ₁ or the second soil S ₂ is suitable for construction, it is transported to the embankment in the middle of construction.

(Modification)
In addition, when it is difficult to distinguish whether the soil to be measured is the first soil _S1 or the second soil _S2 , the properties of the soil may be determined, for example, based on both the particle size distribution measured based on an image obtained by pouring the soil into the opening 11a in the same manner as the first soil and photographing it with the first photographing means, and the particle size distribution measured based on an image obtained by placing the soil inside the housing 11 in the same manner as the second soil and photographing it with the second photographing means.

<3. Effects>
The system 100 described above comprises an imaging device 1 having a portable housing 11 having an opening 11a on the top surface, a first imaging means (camera 12 with lens 12a facing horizontally) that images a first soil _S1 (gravel soil) having a relatively large grain size that is inserted through the opening 11a and falling through the housing 11, and a second imaging means (camera 12 with lens 12a facing downward) that images a second soil _S2 (sandy soil) having a relatively small grain size that is placed inside the housing 11, and a measuring device 2 that measures the grain size distribution of the first soil _S1 based on the image of the first soil _S1 obtained by the first imaging means, and measures the grain size distribution of the second soil _S2 based on the image of the second soil _S2 obtained by the second imaging means.
The method for controlling the quality of embankment materials described above includes an installation step of installing the system 100 at the construction site of the embankment; a sample supply step of feeding a first sample _S1 extracted from the first soil _S1 into the opening _11a when the soil material is the first soil _S1 , and placing a second sample S2 extracted from the second soil _{S2 in the housing 11 when the soil material is the second soil S2 ;} an imaging step of photographing the first sample _S1 falling in the housing 11 by the first imaging means, or photographing the second sample _S2 placed in the housing 11 by the second imaging means; a measurement step of measuring the particle size distribution of the first soil _S1 based on the image of the first sample _S1 obtained in the imaging step, or measuring the particle size distribution of the second soil S2 based on the image of the second sample S2 by the measuring device _{2 ;} and a judgment step of judging whether the first soil _S1 or the second soil _S2 is suitable for construction based on the particle size distribution obtained in the measurement step.

At least the imaging device 1 and the measuring device 2 are portable (small and lightweight), and since measurements are performed using samples extracted from the soil material, they can be easily installed at embankment construction sites where it is difficult to install large-scale equipment.
Furthermore, by installing this system 100 at a construction site, the particle size distribution of the soil that has been brought in can be immediately measured.
Therefore, according to this system 100 or a method for controlling the quality of embankment materials using this system 100, the particle size distribution of soil used as material at the embankment construction site can be easily and quickly measured.

In addition, in the system 100 according to this embodiment, the measuring device 2 also measures the color of the first soil _S1 or the color of the second soil _S2 based on the image of the first soil _S1 or the image of the second soil _S2 obtained by the second photographing means.
In addition, in the fill material quality control method of this embodiment, in a measurement process, the measuring device 2 also measures the color of the first soil _S1 or the color of the second soil _S2 based on the image of the first soil _S1 or the second soil _S2 obtained by the second photographing means, and in a judgment process, it is judged whether the first soil _S1 or the second soil _S2 is suitable for construction based on the particle size distribution and color obtained in the measurement process.

Conventional soil quality control methods using image analysis only measure the particle size distribution of the soil. Therefore, even if the color of the soil delivered at a later date is different from that of the original construction, if the particle size distribution remains the same, the properties of the soil delivered at a later date may be judged to be the same as that of the original construction.
However, according to this system 100 or a method for controlling the quality of fill material using this system 100, for example, even if the particle size distribution of soil brought in at a later date is the same as that at the time of construction, if the color has changed, it can be determined that the properties of the soil brought in at a later date have changed from those at the time of construction, and changes in soil properties that might have been overlooked in the past can be more reliably detected.

Next, an embodiment of the present invention will be described.
FIG. 7 is a graph showing the particle size distribution of the first sample _S1 obtained by the particle size test, and a graph showing the particle size distribution of the first sample _S1 obtained by the system 100. FIG. 8 is a graph showing the particle size distribution of the second sample _S2 obtained by the particle size test, and a graph showing the particle size distribution of the second sample _S2 obtained by the system 100. FIG. 9 is a graph showing the colors of the first to third samples obtained by the system 100.

<Study Overview>
First, a first sample S ₁ (gravel soil) weighing 4 to 6 kg was prepared.
Then, the first sample _S1 was subjected to a grain size test (JIS A 1204).
Furthermore, the particle size distribution of the first sample _S1 was measured using the system 100.
Then, the particle size distribution of the first sample _S1 obtained by the particle size test and the particle size distribution of the first sample _S1 obtained by the system 100 were graphed on the same plane.

Next, a second sample S ₂ (sandy soil) weighing 1 to 2 kg was prepared.
Then, the second sample _S2 was used to carry out the same grain size test as the first sample _S1 .
The particle size distribution of the second sample _S2 was also measured using the system 100.
Then, the particle size distribution of the second sample _S2 obtained by the particle size test and the particle size distribution of the second sample _S2 obtained by the system 100 were graphed on the same plane with the particle size on the horizontal axis and the passing mass percentage on the vertical axis.

In addition, eight types of first samples _S1 (gravel soil) each having a different moisture content, four types of second samples _S2 (sandy soil) each having a different moisture content, and four types of third samples (clay soil) each having a different moisture content were prepared.
Then, the chromaticity and saturation of each sample were measured using the system 100.
Finally, the measured color of each sample was plotted on a plane with chromaticity on the horizontal axis and saturation on the vertical axis.

<Test Results>
A comparison of the graph _G11 showing the particle size distribution of the first sample _S1 obtained by the system 100 with a graph _G12 showing the particle size distribution of the first sample _S1 obtained by a particle size test showed that the two graphs _G11 and _G12 were roughly consistent, as shown in FIG. 7.
Next, the graph _G21 showing the particle size distribution of the second sample _S2 obtained by the system 100 was compared with the graph _G22 showing the particle size distribution of the second sample _S2 obtained by the particle size test. As a result, as shown in FIG. 8, both graphs _G21 and _G22 were roughly consistent, similar to the first sample _S1 .
This indicates that the system 100 can measure particle size distribution with similar accuracy as conventional particle size testing.

In addition, the positions of points _P1 , _P2 , and _P3 indicating the chromaticity and chroma of each sample were compared, and as a result, as shown in Figure 9, points _P1 , _P2 , and _P3 indicating samples of the same type were closely spaced (the chromaticity and chroma were roughly the same) even though the water content was different.
This demonstrates that system 100 can accurately determine soil type without having to dry the sample before measuring color.

100 Filling material quality control system 1 Photographing device 11 Housing 11a Opening 11b Second opening 11c Camera support part 11d Axle rod 12 Camera (first photographing means, second photographing means)
12a Lens 13 Dispersion section 13a Inclined surface 13b Protrusion 13c Hopper 14 First lighting section 15 Second lighting section 16 Receptacle 2 Measuring device 3 Power supply device D Dish G ₁₁ Graph G showing particle size distribution of first soil (sample) obtained by embankment material quality control system ₁₂ Graph G showing particle size distribution of first soil (sample) obtained by particle size test ₂₁ Graph G showing particle size distribution of second soil (sample) obtained by embankment material quality control system ₂₂ Graph N showing particle size distribution of second soil (sample) obtained by particle size test Communication network P ₁ Point P showing chromaticity and saturation of first soil (sample) ₂ Point P showing chromaticity and saturation of second soil (sample) ₃ Point S showing chromaticity and saturation of third soil (sample) ₁ First soil (sample)
S ₂ Second soil (sample)
C Fine component W Water

Claims (5)

A portable housing having an opening on an upper surface;
A first photographing means is provided in the housing and photographs a first soil having a relatively large grain size that is poured through the opening and falling through the housing;
A second photographing means is provided in the housing and photographs a second soil having a relatively small grain size placed in the housing or the first soil;
An imaging device comprising:
a measuring device that measures the particle size distribution of the first soil based on an image of the first soil obtained by the first photographing means, and measures the particle size distribution of the second soil based on an image of the second soil obtained by the second photographing means;
A quality control system for embankment materials comprising: a camera attached to the housing and switchable between a state in which the lens is oriented horizontally and a state in which the lens is oriented downward;
The embankment material quality control system according to claim 1, characterized in that the camera with the lens facing horizontally constitutes the first photographing means, and the camera with the lens facing downward constitutes the second photographing means. The embankment material quality control system according to claim 1 or 2, characterized in that the measuring device also measures the color of the first soil or the color of the second soil based on the image of the first soil or the image of the second soil obtained by the second photographing means. The embankment material quality control system according to any one of claims 1 to 3, characterized in that it comprises a dispersion part having an inclined surface provided above the opening, inclined downward in a direction away from the first imaging means, and at least one protrusion provided on the inclined surface, which disperses the first soil sliding down the inclined surface in a direction along the inclined surface and perpendicular to the direction of the first soil falling down. an installation process for installing an imaging device at a construction site of an embankment, the imaging device comprising: a portable housing having an opening on an upper surface; a first imaging means for imaging a first soil having a relatively large grain size that is poured in through the opening and falling through the housing; and a second imaging means for imaging a second soil having a relatively small grain size that is placed in the housing;
a sample supply step of introducing a first sample extracted from the first soil into the opening when the soil to be used as the material is the first soil, and placing a second sample extracted from the second soil in the housing when the soil to be used as the material is the second soil;
an imaging step of imaging the first sample falling inside the housing by the first imaging means or imaging the second sample placed inside the housing by the second imaging means;
A measuring device measures the particle size distribution of the first soil based on the image of the first soil obtained by the first photographing means, and measures the particle size distribution of the second soil based on the image of the second soil obtained by the second photographing means, a measuring step of measuring the particle size distribution of the first soil based on the image of the first sample obtained in the photographing step, or measuring the particle size distribution of the second soil based on the image of the second sample;
a judgment step of judging whether the first soil or the second soil is suitable for construction based on the particle size distribution obtained in the measurement step;
A method for controlling the quality of embankment materials, comprising: