WO2023233674A1

WO2023233674A1 - Ground improvement method

Info

Publication number: WO2023233674A1
Application number: PCT/JP2022/024844
Authority: WO
Inventors: 碓井博文
Original assignee: 株式会社テノックス九州
Priority date: 2022-06-02
Filing date: 2022-06-22
Publication date: 2023-12-07
Also published as: JP7464299B2; JP2023177571A

Abstract

The present method is a ground improvement method in which a ground improvement body 30 is constructed by mixing cement slurry 26 to which a water-soluble fluorescent dye at a predetermined concentration is added and soil S, the method comprising: a first step of irradiating the ground improvement body 30 with black light from a light source 6; a second step of measuring the ground improvement body 30 irradiated with the black light by the light source 6 using a camera 7a; and a third step of comparing a calculated value based on the data output by the camera 7a with a predetermined threshold value and determining whether or not the cement slurry is in a mixed state.

Description

Ground improvement method

The present invention relates to a soil improvement method that checks the stirring and mixing status of a soil improvement body when creating the soil improvement body in the ground.

As a ground improvement method, there is a deep mixing method that creates a ground improvement body in the ground by discharging cement slurry into the ground and mixing it with mechanical agitation. In this construction method, in order to ensure the quality of the soil improvement body, it is necessary that cement is evenly distributed throughout the soil improvement body, and it is necessary to ensure that cement is evenly distributed throughout the soil improvement body. It is necessary to confirm.

The amount of cement used in on-site construction is determined by the results of mixing tests conducted in the laboratory, and it is necessary to confirm that the cement is evenly distributed in this test as well.

However, when soil and cement slurry are mixed, as will be described later with reference to FIG. 7, both soil and cement slurry have the same color (almost gray) and cannot be distinguished.

Therefore, even if a mixture is illuminated with a normal light source such as a fluorescent light that emits visible light and observed visually or using equipment such as a camera, it is possible to determine whether there is any unevenness in the mixture or whether the mixture is uneven or not. It is extremely difficult to judge whether the condition is good or bad.

Patent Document 1 (Japanese Patent No. 6944605) discloses methods for (1) comparing the brightness of images taken before the improvement with images taken after the improvement, or (2) comparing the state of the ground taken in the past. We propose a method to check the condition of ground improvement bodies by comparing with known images.

However, since the black soil and gray cement are mixed, the difference in brightness is small and it is difficult to distinguish them from each other. In addition, lighting is required deep underground, making it difficult to accurately judge the mixing state.

Further, Patent Document 2 (Japanese Patent No. 4886921) discloses a method of injecting a colored hardening agent and checking the degree of mixing in a ground improvement body based on the distribution of the hardening agent.

However, even when a colored hardener is sprayed onto black-toned soil, as mentioned above, it remains almost black and the difference in brightness is insufficient, making it difficult to distinguish one from the other. Become. In addition, lighting is required deep underground, making it difficult to accurately judge the mixing state.

Furthermore, Non-Patent Document 1 (Japan Building Center "2018 Edition Improvement Ground Design and Quality Control Guidelines for Buildings") states that by spraying a phenolphthalein solution during a stirring condition test, an alkaline reaction (red-purple ) is described.

The discoloration of phenolphthalein is caused by alkaline conditions of pH > 10.0, and is based on the fact that phenolphthalein discolors in areas where cement is present, and indicates the state of cement mixing.

Here, confirmation using phenolphthalein is performed by utilizing the phenomenon in which the area containing cement, which is an alkaline component, changes color to reddish-purple.

However, in reality, the phenolphthalein solution oozes or drips into the surrounding area, which tends to discolor areas that should not originally be discolored. As a result, there is a problem in that the boundary between areas containing cement and areas not containing cement becomes unclear, making it impossible to appropriately determine the mixing state.
Patent No. 6944605 Patent No. 4886921 Japan Building Center "2018 Edition Design and Quality Control Guidelines for Improved Ground for Buildings"

Therefore, an object of the present invention is to provide a ground improvement method that can clearly distinguish between areas where cement slurry is contained and areas where it is not.

The ground improvement method according to the first invention is a ground improvement method in which a cement slurry to which a water-soluble fluorescent dye of a predetermined concentration is added is mixed with soil to construct a ground improvement body, and the ground improvement body is black from a light source. A first step of irradiating light, a second step of measuring the ground improvement body irradiated with black light by a light source using a measuring device, and comparing a calculated value based on data output by the measuring device with a predetermined threshold value. , and a third step of determining whether or not the cement slurry is in a mixed state.

Here, the ground improvement body is irradiated with black light, which is different from visible light, and by using a measuring instrument to measure the ground improvement body irradiated with black light by the light source, it is possible to identify the location where the cement slurry is contained. It becomes possible to clearly distinguish the parts that are not included. Furthermore, whether or not the cement slurry is in a mixed state is determined based on a clear standard of comparing a calculated value based on data output by the measuring device with a predetermined threshold value. Here, even if underground, the water-soluble fluorescent dye illuminated with black light will smoothly emit light, allowing accurate recognition of the condition. Furthermore, the results will not become unstable due to complicated processing or disturbance elements.

Here, the measuring instrument may be a sensor that captures reflected light from the soil improvement body, or a camera that captures an image of the soil improvement body.

The wavelength of the black light is preferably 365 to 405 nanometers. In this way, a light source can be easily secured.

Preferably, the soil is soil at a construction site, and the first, second, and third steps are performed while the ground improvement body is not yet solidified.

According to this configuration, while carrying out ground improvement on site, it is possible to determine whether or not the cement slurry is in a mixed state in parallel.

Preferably, the soil is soil prepared in a laboratory, the first step, the second step, and the third step are performed in the laboratory, and the third step is to determine the appropriate amount of cement addition. It is carried out for the purpose of

According to this configuration, when determining the appropriate amount of cement to be added in the laboratory, the amount of cement to be added can be accurately determined while clearly distinguishing between areas that contain cement slurry and areas that do not. be able to.

According to the present invention, based on a clear standard that clearly distinguishes between areas where cement slurry is present and areas where it is not, and comparing a calculated value based on data output by a measuring device with a predetermined threshold value, It is possible to determine whether the cement slurry is in a mixed state. Therefore, it is possible to make a determination that will not be adversely affected by the shooting conditions, the color of the soil, the level of lighting, etc.

(Embodiment 1)
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1(a) is a side view of the soil improvement device in Embodiment 1 of the present invention, FIG. 1(b) is a partial view showing how to replace the stirring head, and FIG. 2(a) is the same soil improvement device. FIG. 2(b) is a side view showing a state in which the mixing state is examined, and FIG. 2(b) is a partially enlarged cross-sectional view of the inspection head of the soil improvement device.

Embodiment 1 relates to a case where a columnar ground improvement body made of soil S is constructed in a relatively deep location using the ground improvement device (column construction machine) shown in FIG.

As shown in Fig. 1, this ground improvement device includes a base machine 1 that runs on the ground G, a leader 2 that stands up vertically, and a leader 2 that is movable up and down. A drive unit 10 that is supported and includes an actuator such as a motor, a rotation shaft 3 that is given rotational force by the drive unit 10 and rotates horizontally about a vertical axis underground, and is attached to the lower end of the rotation shaft 3. A stirring head 4 is provided.

The stirring head 4 attached to the tip of the rotating shaft 3 is equipped with the following elements. First, at the lower end of the agitation head 4, there is provided an excavation blade 5 which has claws for excavating underground and excavates earth and sand, and this excavation blade 5 is pivotally attached to the rotating shaft 3. As shown in FIG. 1(b), it is desirable that the stirring head 4 is provided with a stirring blade 12 and a co-rotation prevention blade 11 above the excavation blade 5, but these are not essential and may be omitted. .

The type of cement can be selected as usual. Next, a water-soluble fluorescent dye is added to the cement slurry. Water-soluble fluorescent dyes include strontium fluoroborate (SrB4O7F:Eu2+, peak wavelength is 368-371 nm) with a trace amount of europium added, and barium silicide (BaSi2O5:Pb+, peak wavelength is 350-371 nm) with a trace amount of lead added. 353 nanometers), florescen, quinine sulfate, etc. can be suitably used.

More specifically, it is sufficient to use a commercially available fluorescent leakage testing agent (for example, Super Glow Fluorescent Leakage Testing Agent DF-300 (trademark) manufactured by Marktec Co., Ltd.), and it is sufficient to use fluorescent dyes against water. The concentration may be 0.05 to 20 (%). Note that there is usually no need to change the water-soluble fluorescent dye depending on the type of cement.

Next, as shown in FIG. 1(a), the agitation head 4 of the excavation agitation device is set at an initial position close to the ground G, the drive unit 10 is started to operate, and the rotating shaft 3 is rotated. In this way, the excavating blade 5 is brought to the initial depth H1.

Next, below the initial depth H1, the slurry is discharged from the root of the excavation blade 5, and excavation mixing is performed by the stirring head 4. Here, as mentioned above, unlike usual, since a water-soluble fluorescent dye is added to the slurry, the water-soluble fluorescent dye will be mixed in the ground improvement body to be constructed as well. This state continues until the target depth H2 (the lowest part of the soil improvement body to be constructed) is reached.

Thereafter, the stirring head 4 is rotated and raised (raised) until it reaches the ground, thereby constructing a cylindrical ground improvement body using the soil S at the site underground.

After constructing the soil improvement body, while it is still unsolidified, the stirring head 4 is replaced with the inspection head 14 and installed in the apparatus.

FIG. 2(b) is a sectional view of the lower part of the inspection head 14. A portion of the lower part and side of the inspection head 14 is recessed to form a storage chamber 14a. Inside the accommodation chamber 14a, a pair of a light source 6 and a measuring instrument 7 are housed, each facing laterally outward. Note that the storage chamber 14a may be configured to open downward. The light source 6 may be any type of fluorescent lamp, incandescent lamp, mercury lamp, or LED that irradiates the ground improvement body with black light (wavelength: 365 to 405 nanometers) underground, but LEDs are small and easy to use. The measuring device 7 may be a sensor such as a fluorometer or a camera equipped with an image sensor, which measures the ground improvement body irradiated with black light by the light source 6, but in the first embodiment, it is a sensor. . Note that details of the luminescence rate will be described later with reference to FIG. 6.

Further, by attaching a transparent or translucent protective cover 14b to the opening of the storage chamber 14a, the storage chamber 14a is sealed, and the light source 6 and the measuring instrument 7 are protected from surrounding dirt, slurry, etc. be protected as such. The protective cover 8 can be suitably constructed from a resin plate such as acrylic or a tempered glass plate. Therefore, the light source 6 and the measuring instrument 7 move up and down integrally with the rotating shaft 3. The inspection head 14 is pivotally attached to the rotating shaft 3, but the rotating shaft 3 may or may not be rotated when moving the inspection head 14 up and down. Furthermore, the test attachment disclosed in Japanese Patent No. 6742633 can also be applied.

(Embodiment 2)
FIG. 3 is a side view of the soil improvement device in Embodiment 2 of the present invention, FIG. FIG. 3 is a partially enlarged sectional view of the inspection head of the improved device.

Embodiment 2 relates to the case where a flat ground improvement body made of soil S at the site is constructed in a relatively shallow place using the ground improvement device (vertical construction machine) shown in FIG.

As shown in FIG. 3, this ground improvement device includes a main body 21 that runs on the ground G, and an operating section 20 that rotates vertically within a vertical plane and discharges cement slurry and stirs it with the soil S. .

The preparation of cement and the water-soluble fluorescent dye added thereto are the same as in Embodiment 1. Further, after constructing the ground improvement body, a similar inspection head 14 in Embodiment 1 as shown in FIG. 4(b) is attached to the tip of the operating section 20 to inspect the mixing state of cement. Note that details of the luminescence rate will be described later with reference to FIG. 6.

(Embodiment 3)
FIGS. 5(a) to 5(d) show each step of the method in Embodiment 3 of the present invention.

Embodiment 3 is carried out for the purpose of constructing a simulated ground improvement body using soil S prepared in a laboratory and determining an appropriate amount of cement to be added. The preparation of cement and the water-soluble fluorescent dye added thereto are the same as in the first embodiment.

First, as shown in FIG. 5(a), a water-soluble fluorescent dye as described above is added to the cement slurry in the beaker 25, and this is further added to the soil S to obtain a mixture.

Next, as shown in FIG. 5(b), the mixture is placed in a container 27 and mixed and stirred using a mixer 28. After thorough mixing and agitation, as shown in FIG. 5(c), the agitated soil 30 is placed in a vat 29 having a predetermined volume to the full extent.

Next, as shown in FIG. 5(d), the bat 29 prepared as described above is placed in the dark room 31. In the dark room 31, a light source 6 that emits black light and a camera 7a serving as a measuring device that photographs the stirred soil 30 in the vat 29 that is irradiated with the black light from the light source 6 are arranged.

Next, examples of actual photography will be explained with reference to FIGS. 7 to 10. FIG. 7 shows that in the state of FIG. 5(d), visible light (a fluorescent lamp or the like or sunlight itself may be used) without using the light source 6 that irradiates a black light. This is an example of a photo taken using . This photo may be in full color or in grayscale. A characteristic feature of the screen is that there is almost no difference in shading throughout the screen, making it difficult to distinguish between light and dark.

On the other hand, FIG. 8 is a photograph taken of the same object as in FIG. 7, using black light (wavelength: 365 to 405 nanometers) irradiated by the light source 6 instead of visible light. This photo may be in full color or in grayscale. What can be said characteristically is that the difference in shading appears more clearly than in FIG. 7 over the entire screen, making it easier to distinguish between light and dark.

When the image in FIG. 7 (here, full color) is converted to grayscale, it becomes as shown in FIG. 9, and when it is further converted into black and white, it becomes as shown in FIG. 10. To reduce colors, well-known techniques such as approximate colors, patterns, error diffusion methods, etc. may be used.

When using a camera image, data on a two-dimensional plane is usually obtained, so it is desirable to calculate the luminescence rate (%) on a pixel-by-pixel basis. In other words, in the example of FIG. 10, the total number of pixels A is 236672 pixels, and the number B of pixels in the white part is 1641778 pixels, so luminous rate (%) = (A/B) * 100 = (1641778/ 2336672)*100=70(%).

In the third embodiment, TH=80(%) is adopted as the threshold value for determining the quality of the luminescence rate (%). Needless to say, this numerical value is only an example, and it should be understood that even if a higher or lower threshold value is used, it still falls within the protection scope of the present invention. Therefore, in the above numerical example, the luminescence rate is insufficient and the mixed state is denied. In other words, the amount of solution in the beaker 25 relative to the soil S should be increased. On the other hand, if the luminescence rate is 80 (%) or more, the mixed state is confirmed.

As described above, the following points are common to Embodiments 1 to 3.

In accordance with Embodiment 3, when constructing the soil improvement body 30 by mixing cement slurry with a predetermined concentration of water-soluble fluorescent dye added and soil S, black light is applied to the soil improvement body 30 from the light source 6. A second step of measuring the ground improvement body 30 irradiated with black light by the light source 6 using the measuring device 7a, and calculating a calculated value based on the data outputted by the measuring device 7a and a predetermined threshold value. and a third step of comparing the above and determining whether or not the cement slurry is in a mixed state.

The wavelength of the black light emitted by the light source 6 is 365 to 405 nanometers.

In Embodiments 1 and 2, the soil S is soil at a construction site, and the first, second, and third steps are performed while the ground improvement body has not yet solidified.

In Embodiment 3, the soil S is soil prepared in a laboratory, the first step, the second step, and the third step are carried out in the laboratory, and the third step is performed by adding appropriate cement. It is carried out for the purpose of determining the amount.

With reference to FIG. 6, the configuration of the information processing device in the equipment of Embodiments 1 to 3 will be described. FIG. 6 is a functional block diagram of an information processing apparatus in Embodiments 1 to 3 of the present invention. First, the light source 6, measuring device 7, etc. are as already described.

Of this device, the storage unit 40 consists of a storage such as a memory or a hard disk for storing control programs (including well-known processes for image processing) and various data to be temporarily stored.

The control unit 41 includes a processor and the like, and executes a control program stored in the storage unit 40 to control peripheral elements.

The monitor 42 is a display that displays the operating status to the user.

The interface 43 is controlled by the control unit main body 21 to turn on/off the light source 6 and input a measurement value (measurement signal) from the measuring device 7.

Next, the luminescence rate calculated by the luminescence rate calculation unit 44 will be explained.

Regarding the third embodiment, as already explained with reference to FIG. 10, when the total number of pixels is A and the number of pixels in the white part is B,
Luminescence rate (%) = (A/B) * 100 (%) (1)
And it is sufficient.

In the first and second embodiments, the measuring instrument 7 moves linearly, so distance may be used.

If the distance L that the inspection head 14 moves and the distance that the measuring instrument 7 captures the reflected light is l, then
Luminous rate = (l/L) * 100 (%) (2)
And it is sufficient.

Of course, the above formula is merely an example, and it goes without saying that various different formulas or equivalent formulas can be used as long as the gist of the present invention is not changed.

(a) Side view of the soil improvement device in Embodiment 1 of the present invention (b) Partial view showing how to replace the stirring head in Embodiment 1 of the present invention (a) Side view showing a state in which the excavation agitation device in Embodiment 1 of the present invention examines the mixing state (b) A partially enlarged sectional view of the inspection head of the excavation agitation device in Embodiment 1 of the present invention Side view of the ground improvement device in Embodiment 2 of the present invention (a) Side view showing a state in which the excavation agitation device according to Embodiment 2 of the present invention examines the mixing state (b) A partially enlarged sectional view of the inspection head of the excavation agitation device according to Embodiment 2 of the present invention (a) An explanatory diagram of each process in Embodiment 3 of the present invention (b) An explanatory diagram of each process in Embodiment 3 of the present invention (c) An explanatory diagram of each process in Embodiment 3 of the present invention (d ) Explanatory diagram of each process in Embodiment 3 of the present invention Functional block diagram of information processing apparatus in Embodiments 1 to 3 of the present invention Photograph taken of the soil surface under natural light in Embodiment 3 of the present invention A photograph taken of the soil surface using a black light in Embodiment 3 of the present invention Diagram showing a grayscale image of Figure 8 A diagram showing an image obtained by converting FIG. 9 into black and white

1 Base machine 2 Reader 3 Rotating shaft 4 Stirring head 5 Excavation blade 6 Light source 7 Measuring device 7a Camera 10 Drive unit 11 Co-rotation prevention blade 12 Stirring blade 14 Inspection head 14a Accommodation chamber 14b Protective cover 20 Operating unit 21 Main body 25 Beaker 26 Solution 27 Container 28 Mixer 29 Vat 30 Mixed soil 31 Dark room 40 Storage unit 41 Control unit 42 Monitor 43 Interface 44 Luminous rate calculation unit G Ground S Soil H1 Initial depth H2 Target depth

Claims

A ground improvement method in which a soil improvement body is constructed by mixing cement slurry with a predetermined concentration of water-soluble fluorescent dye added and soil, the method comprising:
A first step of irradiating the ground improvement body with black light from a light source;
a second step of measuring the ground improvement body irradiated with black light by the light source using a measuring instrument;
A ground improvement method comprising: a third step of comparing a calculated value based on data output by the measuring device with a predetermined threshold value to determine whether or not the cement slurry is in a mixed state.
The ground improvement method according to claim 1, wherein the measuring device is a sensor that captures reflected light from the ground improvement body.
The ground improvement method according to claim 1, wherein the measuring device is a camera that takes an image of the ground improvement body.
The ground improvement method according to claim 1, wherein the wavelength of the black light is 365 to 405 nanometers.
The soil improvement according to claim 1, wherein the soil is soil at a construction site, and the first step, the second step, and the third step are performed while the ground improvement body is not yet solidified. Method.
The soil is soil prepared in a laboratory, the first step, the second step, and the third step are performed in the laboratory, and the third step is performed by adding an appropriate amount of cement. The ground improvement method according to claim 1, which is carried out for the purpose of determining.