JP7616639B2 - Soil reformation state measuring method and soil reformation state measuring device - Google Patents

Description

The present invention relates to a method for measuring the state of soil modification when modifying the soil by introducing a modifier.

Traditionally, methods of introducing modifiers into the ground have been used to improve the ground's earthquake resistance and to prevent the elution of heavy metals. These modifiers include cement milk (cement-based solidifier), lime-based solidifier, composite solidifiers that are a mixture of cement and lime, polymer-based solidifiers, and grout materials that use inorganic and organic hardeners and water glass, etc.

There are various ground improvement methods. For example, when improving the ground from the surface to a depth of about 2m, a backhoe or stabilizer is used to spread powdered cement- or lime-based solidification material (modifier) and mix it with the soft soil.

When carrying out ground improvement work in the middle layers, about 1 to 15 meters deep from the ground surface, for example, a trencher method is used. In the trencher method, an excavator that rotates a bucket-shaped agitator vertically by connecting it with a chain or the like, or an excavator that rotates an agitator blade, is used to mix and stir the soil underground with the modifier.

Furthermore, when carrying out ground improvement work at depths of 10m or more from the ground surface, in addition to the method of mixing and stirring the soil and modifier underground using an excavator with rotating mixing blades, high-pressure jet mixing methods are often used. There are various high-pressure jet mixing methods, such as high-pressure jet injection of air or water simultaneously with or separately from the modifier to mix and stir the modifier and soil, or high-pressure jet injection of the modifier directly into the ground to mix the soil and modifier. In either case, this high-pressure jet mixing method uses the force of the jet injection of gas or liquid to mix the materials, making it essential to measure the extent to which the ground has been improved by the modifier as early as possible.

For example, Patent Document 1 proposes a technology to measure the extent of ground improvement by penetrating a rod-shaped member horizontally (radially) into the soil from a borehole through which a high-pressure jet is injected and measuring the pH or temperature.

For example, Patent Document 2 proposes a technology to measure the extent of ground improvement by penetrating a rod equipped with a camera into the ground at a point away from the borehole from which the high-pressure jet is injected, displaying the image captured by the camera on a monitor, and confirming the presence of the modifying agent liquid.

Patent No. 4721268 Patent No. 4886921

However, in Patent Document 1, when a rod-shaped member is inserted horizontally into the soil, there is a possibility that the modifier will diffuse through the penetration hole, making it difficult to accurately measure the area of ground improvement. To solve this problem, it is necessary to wait until the modifier hardens before forming the penetration hole, which reduces measurement efficiency and poses the problem that after hardening, it is difficult to carry out repairs after discovering that no modification is necessary.

In addition, in Patent Document 2, there is a problem that it is difficult to determine the presence of the modifier liquid from the image of the inner peripheral wall of the penetration hole. Therefore, in Patent Document 2, it is necessary to spray a coloring agent to color the modifier and then measure the inner wall with a camera, but since it is difficult to cause the coloring agent and the modifier to react in the soil, there are cases where the modifier is not properly colored, resulting in a problem of poor measurement accuracy.

In light of this situation, the present invention aims to provide a technology that can reliably and accurately measure the state of ground modification.

The present invention, which achieves the above-mentioned object, is a soil reforming state measurement method for measuring the diffusion state of a soil reforming agent introduced into the ground, characterized in that it includes a solution measurement step for measuring the physical properties of the reforming agent that accumulates inside a vertical hole formed in a place where the reforming agent is assumed to be mixed with the soil, or the physical properties of the reforming agent solution that is generated by dissolving the reforming agent in a solvent that accumulates inside the vertical hole.

In relation to the above-mentioned soil reform state measurement method, the solvent may be groundwater.

The above-mentioned soil reforming state measurement method may be characterized by including a solvent supplying step for supplying the solvent to the vertical hole.

In relation to the above-mentioned soil reforming state measurement method, it may be characterized in that the electrical characteristics of the reforming agent or the reforming agent solution are measured as the physical property value.

In relation to the above-mentioned soil reforming state measurement method, it may be characterized in that the temperature of the reforming agent or the reforming agent solution is measured as the physical property value.

In relation to the above-mentioned soil modification state measurement method, the physical property value may be measured to be at least one of the pH value, electrical conductivity, redox potential, and ion concentration of the modifier or the modifier solution.

In relation to the above-mentioned soil modification state measurement method, a solution transfer process for transferring the modifier or the modifier solution may be provided, and the solution measurement process may be characterized in that it measures the physical property value of the modifier or the modifier solution transferred by the solution transfer process.

In relation to the above-mentioned soil reforming state measurement method, a feature may be that the sensor for measuring the physical property value is moved relative to the reforming agent or the reforming agent solution at the contact portion between the sensor and the reforming agent or the reforming agent solution.

In relation to the above-mentioned soil modification state measurement method, the physical property value may be measured multiple times at a common depth by intervening relative movement between the modifier or the modifier solution and the sensor.

In relation to the above-mentioned soil reforming state measurement method, the solution transfer process may be characterized in that the modifier or modifier solution being transferred is passed through a filter, and the solution measurement process may be characterized in that the physical property values of the modifier or modifier solution that has passed through the filter are measured.

In relation to the above-mentioned soil modification state measurement method, the solution moving step may be characterized in that the modifier or the modifier solution is moved to the ground.

In relation to the above-mentioned soil modification state measurement method, the solution measurement step may be characterized in that the physical property values of the modifier or the modifier solution that has been moved to the ground are measured.

The above-mentioned soil reforming state measurement method may be characterized by including an inner wall imaging process for imaging the inner wall of the vertical hole.

In relation to the above-mentioned soil reforming state measurement method, the reforming material may be made to contain an electrolyte for detection in advance, and the solution measurement process may be characterized in that the ion concentration of the electrolyte is measured.

The present invention, which achieves the above-mentioned object, is a soil reforming state measuring device that measures the diffusion state of a soil reforming agent impregnated into the ground, and is characterized by comprising an insertion member that is inserted into a vertical hole formed in a place where the reforming agent is assumed to be mixed with the soil, and a sensor that is placed in the insertion member and detects the physical property values of the reforming agent that accumulates inside the vertical hole or the physical property values of the reforming agent solution that is generated by dissolving the reforming agent in a solvent that accumulates inside the vertical hole.

The soil reforming state measuring device may be characterized by having a solvent supplying means for supplying the solvent to the vertical hole.

In relation to the above soil modification state measuring device, the sensor may be characterized by detecting electrical characteristics of the modifier or the modifier solution.

The soil modification state measuring device may be characterized in that it is provided with a temperature detection unit that is disposed in the insertion member and detects the temperature of the modifier or the modifier solution.

In relation to the above soil modification state measuring device, the sensor may be characterized by detecting at least one of the pH value, electrical conductivity, redox potential, and ion concentration of the modifier or the modifier solution.

In relation to the above soil modification state measuring device, the device may be characterized in that it includes a solution movement path provided in the insertion member to guide the modifier or the modifier solution, and the sensor detects the physical property values of the modifier or the modifier solution taken into the solution movement path.

The soil modification state measuring device may be characterized by having a solution moving means for moving the modifier or the modifier solution in the solution movement path.

In relation to the above soil modification state measuring device, it may be characterized in that it is provided with a filter for filtering the modifier or the modifier solution, and the sensor detects the physical property value of the modifier solution that has passed through the filter.

In relation to the above-mentioned soil modification state measuring device, the solution movement path may be characterized in that it guides the modifier or the modifier solution to the ground.

The soil reforming state measuring device may be characterized in that it is provided with an imaging device that is disposed in the insertion member and captures an image of the inner wall of the vertical hole.

In relation to the above soil reforming state measuring device, the insertion member may have a sensor housing section in which the sensor is disposed, and an imaging device housing section in which the imaging device is disposed, and the sensor housing section and the imaging device housing section may be characterized in that they are freely separable.

The soil reforming state measuring device may be characterized in that the sensor housing is disposed above the imaging device housing.

The present invention, which achieves the above-mentioned object, is a soil reforming state measuring device that measures the mixed state of soil modifiers impregnated in the ground, and is characterized by comprising: a pumping means that is inserted into a vertical hole formed in a place where the modifier is assumed to be mixed, and pumps up to the ground the modifier that accumulates inside the vertical hole or a modifier solution that is generated by dissolving the modifier in a solvent that accumulates inside the vertical hole; and a sensor that is placed on the ground and detects the physical property values of the modifier or the modifier solution that is pumped up to the ground by the pumping means.

The present invention has the excellent effect of being able to measure the state of ground modification reliably and with high accuracy.

1 is a front view showing the overall configuration of a soil reforming state measuring device according to an embodiment of the present invention. 2A is a front view showing an enlarged view of an insertion member of the soil reformation state measuring device, and FIG. 2B is a front cross-sectional view showing the same. 1A to 1D are process diagrams showing a method for measuring a soil reformed state according to an embodiment of the present invention. 2 is a block diagram showing the functional configuration of a control device of the soil modification state measuring device. FIG. 2 is a flowchart of the soil reformation state measuring method. 1A is a front cross-sectional view showing the operation of the insert during measurement, and FIG. 1B is a graph showing a sample of the measured data. 1 is a graph showing sample data measured by the soil reformation state measuring method. 13 is an enlarged front cross-sectional view showing a modified example of the insertion member of the soil reformation state measuring device. FIG. 1A is a front view showing an enlarged view of a modified example of the insertion member of the soil reformation state measuring device, and FIG. 13A is a front cross-sectional view showing the operation of the insertion member according to the modified example during measurement, and FIG. 13B is a graph showing a sample of the measured data. FIG. 13 is a front view showing the overall configuration of a soil modification state measuring device according to a modified example.

The following describes an embodiment of the present invention with reference to the attached drawings.

<Overall structure of the soil reformation status measuring device>

Figure 1 shows the overall structure of a soil reforming state measuring device 1 according to an embodiment of the present invention. This soil reforming state measuring device 1 includes an excavation device (insertion device) 10 that excavates a vertical hole 5 in the ground, an insertion member 20 that is inserted into the vertical hole 5, a sensor 50 provided on the insertion member 20, a temperature detection unit 58 provided on the insertion member 20, and an imaging device 65 provided on the insertion member 20. The insertion member 20 is fixed to the lower end of a plurality of insertion rods 12 that are connected to each other. By moving the insertion rods 12 up and down using the excavation device 10, the insertion member 20 advances and retreats in the vertical direction within the vertical hole 5. In other words, the excavation device 10 also serves as a moving mechanism that moves the insertion member 20 up and down.

The soil reforming state measuring device 1 further has a solvent supply path 30 that supplies water as a solvent to the vertical hole 5 via the outlet 30A of the insertion member 20. A solvent tank 32 is provided on the ground, and the solvent supply path 30 connects the outlet 30A and the solvent tank 32. A liquid delivery pump 33 that serves as a solvent transport means is provided in the middle of the solvent supply path 30, and the solvent (water) in the solvent tank 32 is sucked in and discharged from the outlet 30A. The solvent transport means is not limited to the liquid delivery pump 33, and a pressure control device (compressor) that controls the pressure in the internal space of the solvent tank 32 can be provided, and the solvent can be delivered to the solvent supply path 30 side by controlling the internal pressure. A control valve can be provided in the middle of the solvent supply path 30 to control the solvent delivery state.

The vertical hole 5 stores a modifier solution Y, which is generated by dissolving the soil modifier in the water that acts as a solvent. The water that acts as the solvent may be supplied from above ground, or it may be groundwater that is already present underground.

The insertion member 20 is provided with a solution movement path 40 (see FIG. 2). One end (lower end) of the solution movement path 40 is connected to the suction port 40A of the insertion member 20. As a result, the modifier solution Y present in the vertical hole 5 flows into the inside of this solution movement path 40. A solution tank 42 is provided on the ground. The solution movement path 40 is extended from the insertion member 20 toward the ground, and the other end is connected to the solution tank 42. A pressure control device 43, which serves as a solution movement means, is connected to the solution tank 42 to control the internal pressure in the solution tank 42. In this embodiment, the pressure control device 43 is, for example, a vacuum pump, and when the gas in the solution tank 42 is exhausted to lower the internal pressure, the modifier solution Y in the vertical hole 5 is sucked into the solution movement path 40, sucked up to the ground, and flows into the solution tank 42. On the other hand, when the pressure control device 43 stops exhausting the solution tank 42 and increases the internal pressure, the suction of the modifier solution Y in the vertical hole 5 is stopped. The pressure control device 43 can also pressurize the solution tank 42 to cause the aspirated modifier solution Y to flow back underground. Although the solution moving means is illustrated here as a pressure control device 43, a liquid delivery pump may also be used. The delivery state (movement state) of the modifier solution Y may be controlled by providing a control valve midway along the solution movement path 40.

The soil reforming state measuring device 1 further includes a control device 70 arranged on the ground. The control device 70 includes a controller 71 and a personal computer 80. The controller 71 receives detection signals (detection currents) from the sensor 50 and the temperature detector 58 via the detection wiring 72. The controller 71 receives a video signal from the imaging device 65 via the video wiring 74. The controller 71 also receives information on the insertion distance (insertion depth) of the insertion member 20 from the ground by the drilling device 10 via the position information wiring 76. The controller 71 can control the pressure control device 43, the liquid delivery pump 33, and various control valves (not shown). The controller 71 is connected to a personal computer 80 having a display. Note that, although a configuration including the controller 71 and the personal computer 80 is illustrated here, a single computer can also function as both the controller 71 and the personal computer 80. Of course, they can also be distributed among multiple computers.

The controller 71, which is a part of the control device 70, has a built-in so-called calculator (not shown), and more specifically, includes a CPU, RAM, ROM, an input/output interface, a bus, etc. The CPU is a so-called central processing unit, and various programs are executed to realize various functions of the control device 70. The RAM is a random access memory, and is used as a working area for the CPU. The ROM is a read-only memory, and stores the basic OS and various programs (e.g., a soil reforming state measurement program) executed by the CPU. The input/output interface receives operation information from the input keys, the keyboard and mouse of the personal computer 80. The input/output interface receives and outputs control signals between the power supply that operates the storage device, the detection wiring 72, the video wiring 74, the pressure control device 43, the liquid delivery pump 33, and the personal computer 80. The bus is a wiring that integrally connects the CPU, RAM, ROM, input device, input/output interface, etc. to communicate. When the basic OS and soil reforming state measurement program stored in the ROM are executed by the CPU, soil reforming state measurement is performed by the soil reforming state measurement device 1.

<Detailed structure of the insert>

Figure 2 shows the detailed structure of the insertion member 20. The insertion member 20 has a sensor housing section 22 that houses the sensor 50, and an imaging device housing section 60 that houses the imaging device 65. The sensor housing section 22 and the imaging device housing section 60 are detachably connected by a screw fastening structure.

The sensor housing 22 has a cylindrical sensor side housing 24. A male thread 24A is formed on the outer periphery of the upper end of the sensor side housing 24, which screws into a female thread formed at the lower end of the insertion rod 12 (see FIG. 1). A female thread 24B is formed on the inner periphery of the lower end of the sensor side housing 24, which screws into the imaging device housing 60. An outlet 30A opens on the periphery of the sensor side housing 24. A solvent supply path 30 is housed inside the sensor side housing 24, and one end of the path is connected to the outlet 30A. The other end of the solvent supply path 30 extends to the upper end side of the sensor side housing 24 and into the rod 12. The other end of the solvent supply path 30 reaches the solvent (water) in the solvent tank 32 on the ground. As a result, the solvent (water) in the solvent tank 32 is discharged from the outlet 30A into the vertical hole 5 via the solvent supply path 30. In this example, the solvent supply path 30 and the discharge port 30A are provided in the sensor housing 22, but they may be provided in a housing (dedicated solvent supply side housing) of a separate member (dedicated solvent supply path housing) separated from the sensor housing 22.

An intake port 40A opens on the periphery of the sensor side housing 24. A solution movement path 40 is housed inside the sensor side housing 24, and one end of the path is connected to the intake port 40A. The other end of the solution movement path 40 extends to the upper end side of the sensor side housing 24 and into the insertion rod 12. The other end of the solution movement path 40 reaches a solution tank 42 on the ground. As a result, the modifier solution Y that accumulates in the vertical hole 5 is sucked in from the intake port 40A and discharged into the solution tank 42 via the solution movement path 40.

A filter 44 is placed in the middle of the solution flow path 40 (here, at the intake port 40A). This filter 44 filters out gravel, soil, etc. contained in the modifier solution Y. Furthermore, in the middle of the solution flow path 40, downstream of the filter 44 (here, the intake port 40A is defined as the upstream side), a buffer space 40B is formed that is larger than the other flow paths. A sensor 50 and a temperature detection unit 58 are placed on the peripheral wall that defines this buffer space 40B, and come into contact with the modifier solution Y passing through the buffer space 40B to measure its physical properties and temperature.

The sensor 50 in this embodiment is a pH meter and has a sensitive electrode 51 and a comparison electrode 52. The sensitive electrode 51 is a glass electrode, which selectively responds to hydrogen ions in the modifier solution Y by a glass response membrane and outputs an electromotive force (electric potential) corresponding to the pH value of the modifier solution Y. The comparison electrode 52 outputs a stable electric potential that is not dependent on the pH value of the modifier solution Y. As a result, the sensor 50 can measure the pH value based on the electric potential difference between the sensitive electrode 51 and the comparison electrode 52. The temperature detection unit 58 measures the temperature of the modifier solution. Since the electromotive force (electric potential) generated in the sensitive electrode 51 changes depending on the temperature of the modifier solution Y, the electromotive force (electric potential) is corrected (compensated) using the measured temperature. The detection signals (detection current and detection electric potential) of the sensor 50 and the temperature detection unit 58 are transmitted to the control device 70 via the detection wiring 72.

In this embodiment, the sensor 50 is a pH meter, but the present invention is not limited to this. The sensor 50 may be any sensor capable of detecting the electrical characteristics of the modifier solution Y. The sensor 50 may be any sensor capable of detecting the physical properties of the modifier solution. For example, the sensor 50 may be a conductivity meter, an oxidation-reduction potentiometer, an ion concentration meter, or the like.

The imaging device housing 60 has a cylindrical imaging device side housing 64. A male thread 64A is formed on the outer periphery of the upper end of the imaging device side housing 64, which screws into a female thread 24B formed on the lower end of the sensor side housing 24. A female thread 64B is formed on the inner periphery of the lower end of the imaging device side housing 64, which screws into a conical tip cone 69. An imaging port 65A opens on the peripheral surface of the imaging device side housing 64. An imaging device 65 is fixed inside the imaging device side housing 64, and its imaging lens faces the imaging port 65A. As a result, the imaging device 65 can capture an image of the inner wall of the vertical hole 5. The video signal of the imaging device 65 is transmitted to the control device 70 via the video wiring 74.

In this insertion member 20, the sensor housing 22 is located at the top and the imaging device housing 60 is located at the bottom. That is, the movement range of the imaging device 65 is wider than the movement range of the sensor 50 inside the vertical hole 5. For example, if there is a large error in the physical property values of the modifier solution measured by the sensor 50 or if the physical property values include abnormal values, the cause of the error etc. can be visually analyzed using the wider range of the inner wall image of the imaging device 65.

In addition, since it is equipped with a tip cone 69, the vertical hole 5 itself can be excavated at the same time by penetrating the insertion member 20 into the soil using the excavation device 10. In other words, the insertion member 20 can also simultaneously perform the excavation process of excavating the vertical hole 5.

If the imaging device housing 60 is omitted, the tip cone 69 can be screwed into the female threaded portion 24B of the sensor side housing 24.

<Method for measuring soil reform status>

Next, the procedure for measuring the soil reforming state will be explained with reference to the schematic diagram of the external appearance in FIG. 3, the functional configuration block of the measurement program in the control device 70 in FIG. 4, the measurement flow in FIG. 5, and the measurement data values in FIG. 6 and FIG. 7.

First, as shown in FIG. 3(A), before soil reforming, a vertical hole 5 is excavated by inserting an insertion member 20 using an excavation device 10 and an insertion rod 12, etc., inside the planned area P where soil reforming will be performed in the future and at a position where confirmation of the effective reforming area is required (measurement vertical hole excavation step S112). This vertical hole 5 is located away from the reforming central axis C where the reforming material is introduced into the ground. Note that, although an example is shown here of excavating the vertical hole 5 at the same time as inserting the insertion member 20, the method of excavating the vertical hole 5 is not particularly limited, and it may be excavated separately using another excavation device.

Next, as shown in FIG. 3B, the drilling device 10 and the insertion rod 12 are used to insert the insertion member 20 into the vertical hole 5 (insertion member insertion step S114). As already mentioned, in this embodiment, the insertion member insertion step S114 is completed at the same time as the measurement vertical hole drilling step S112. As a preliminary preparation for the measurement vertical hole drilling step S112 or the insertion member insertion step S114, as shown in FIG. 1, the detection wiring 72, the video wiring 74, the solvent supply path 30, and the solution movement path 40 are inserted in advance into the multiple insertion rods 12 that can correspond to the maximum depth of the insertion member 20, and the insertion member 20 is penetrated into the ground while the insertion rods 12 are added.

Then, the soil reforming state measuring device 1 discharges water, which serves as a solvent, from the outlet 30A of the insertion member 20 to fill the vertical hole 5 with the solvent (solvent injection step S116). The solution injection processing unit 710 in the control device 70 controls the liquid delivery pump 33 to suck up the solvent (water) in the solvent tank 32 and discharge it from the outlet 30A. Note that if the ground is rich in groundwater and the groundwater naturally fills the vertical hole 5 after excavation, this solvent injection step may be omitted.

If necessary, wait for a while in this state to allow the soil components to fully dissolve into the solvent (water) in the vertical hole 5 so that the physical properties of the pre-modified solution Z become stable.

Next, the insertion member 20, which is located at the deepest position, is raised continuously or stepwise, and the physical property value (here, pH value) of the pre-modified solution Z, into which the soil components have dissolved, is measured at multiple measurement depths using the sensor 50 and temperature detection unit 58 (solution transfer process and pre-measurement process S118). At this time, the imager 65 also captures an image of the inner wall of the vertical hole 5.

In more detail, as shown in FIG. 6(A), when measuring the pH value at a specific depth (for example, a depth of -16.0 m), the depth information storage unit 730 of the control device 70 judges whether the insertion member 20 is located at the correct depth (-16.0 m) based on a signal from the drilling device 10. If necessary, the drilling device 10 may be controlled to reposition the insertion member 20 at the correct depth. After that, the solution movement processing unit 720 in the control device 70 controls the pressure control device 43, which serves as the solution movement means, to exhaust the gas in the solution tank 42. As a result, the pre-modified solution Z having a water pressure corresponding to a depth of -16.0 mm flows into the buffer space 40B through the intake port 40A and rises along the solution movement path 40 (see dotted arrow/solution movement process). As a result, the solution and the sensor 50 move relative to each other at the contact portion between the sensor 50 and the pre-modified solution Z.

The measurement processing unit 740 of the control device 70 measures the pH of the solution multiple times while the pre-modified solution Z moves within the buffer space 40B, and multiple pH values at a specific depth (-16.0 m) are detected as shown in FIG. 6 (B). The measurement processing unit 740 determines the final pH value at the specific depth based on the multiple pH values. The final pH value may be determined by using the average value of all of these multiple pH values, or by using the remaining data obtained by removing noise components (e.g., data or data groups on the maximum and minimum sides) from the multiple pH values to calculate the average value, or by using other methods. In any case, it is preferable to reduce measurement errors by aspirating the pre-modified solution Z at a depth of -16.0 m and measuring the pH value of the pre-modified solution Z multiple times while moving it relative to the sensor 50.

As a result of the above, for example, as shown by the white circles in Figure 7, the pH value of the soil of the pre-modified solution Z is measured at multiple depths (here, at depths of 2.0 m each).

After that, as shown in FIG. 3(C), the central axis C of the modification is excavated to excavate a vertical hole 200 for modification, a jet nozzle for spraying the modification material is inserted, and the modification material is sprayed at high pressure radially from the central axis C of the modification (ground modification process S120). As a result, the force of the jet spray stirs and mixes the modification material and the soil, forming an area Q where the ground has been improved by the modification material. Note that, although the present embodiment illustrates a case where the improvement area Q of the ground is cylindrical, the present invention is not limited to this, and various shapes such as a fan shape or a radial shape are possible.

Next, as shown in FIG. 3(D), the soil reforming state measuring device 1 uses the excavation device 10 and the insertion rod 12, etc. to insert the insertion member 20 into the vertical hole 5 again (insertion member inserting step S122). Note that even if the vertical hole 5 has disappeared due to the ground reforming step S120, the tip cone 69 of the insertion member 20 can be used to excavate a new vertical hole 5 at the same time as the insertion. Note that the present invention is not limited to this, and a vertical hole 5 for measurement may be excavated again using another device before the insertion member inserting step S122.

Thereafter, the soil modification state measuring device 1 again discharges water as a solvent from the outlet 30A of the insertion member 20 to fill the vertical hole 5 with the solvent (solvent injection step S124). Note that this solvent injection step S124 can be omitted in the following cases (1) or (2).
(1) When the liquid modifier itself is sufficiently filled in the vertical hole 5.
(2) The ground is rich in groundwater that can act as a solvent, and the groundwater naturally fills the vertical hole 5 after excavation, causing at least some of the components of the jetted modifier to dissolve in the groundwater (solvent) and produce a modifier solution.

On the other hand, for example, if the modifier has high viscosity or is difficult to dissolve in groundwater, it is preferable to eject a dedicated solvent in which the modifier is easily dissolved from the outlet 30A of the insertion member 20 and fill it with the modifier solution.

Next, while the insertion member 20 located at the deepest position is raised continuously or stepwise, the physical property value (here, pH value) of the modifier itself or the modifier solution in which the modifier has dissolved in water (hereinafter, these are collectively referred to as modifier solution Y) is measured at multiple measurement depths using the sensor 50 and temperature detection unit 58 (solution movement and post-measurement step S126). At this time, the imager 65 also captures an image of the inner wall of the vertical hole 5.

In the post-measurement step S126, as shown in FIG. 6A, when the pH value is measured at a specific depth (for example, a depth of -16.0 m), the depth information storage unit 730 of the control device 70 judges whether the insertion member 20 is located at the correct depth (-16.0 m) based on a signal from the drilling device 10. If necessary, the drilling device 10 may be controlled to position the insertion member 20 at the correct depth. After that, the solution movement processing unit 720 in the control device 70 controls the pressure control device 43, which serves as the solution movement means, to exhaust the gas in the solution tank 42. As a result, the modifier solution Y having a water pressure corresponding to a depth of -16.0 mm flows into the buffer space 40B through the intake port 40A and rises along the solution movement path 40 (see dotted arrow/solution movement step). As a result, the modifier solution Y and the sensor 50 move relative to each other at the contact portion between the sensor 50 and the modifier solution Y. The measurement processing unit 740 of the control device 70 measures the pH of the modifier solution Y multiple times while moving the modifier solution Y in the buffer space 40B, and multiple pH values at a specific depth (-16.0 m) are detected as shown in FIG. 6B. The measurement processing unit 740 determines the final pH value at the specific depth based on the multiple pH values. The final pH value may be determined by using the average value of all of the multiple pH values, but other methods may also be used to calculate the average value, etc., using the remaining data obtained by removing noise components (e.g., data or data groups on the maximum and minimum sides) from the multiple pH values. In any case, the measurement error is reduced by measuring the pH value of the modifier solution Y multiple times while sucking and moving the modifier solution Y at a depth of -16.0 m.

Through the above steps, for example, as shown by the black circles in Figure 7, the pH value of the modifier solution Y is measured at multiple depths (here, at depths of 2.0 m each). If the modifier is cement milk, the modifier solution Y tends to be alkaline, and the pH value increases compared to the pre-modification solution Z.

Finally, the comparison processing unit 750 in the control device 70 compares the pH value (white circle) of the pre-reformed solution Z in FIG. 7 with the pH value (black circle) of the modifier solution Y, etc., and if the difference value exceeds the desired threshold, it is determined that the modification has been performed appropriately (comparison step S128). On the other hand, if the difference value is below the desired threshold, it is determined that the modification has been insufficient.

As described above, the soil reformed state measuring device 1 and the soil reformed state measuring method of this embodiment utilize a vertical hole 5 excavated specifically for measurement, and store the modifier itself or a modifier solution Y generated by dissolving at least a portion of the modifier in the vertical hole 5, and measure its physical properties, making it possible to measure the reformed state of the soil with high accuracy. Also, if there is a shortage of the modifier itself in the vertical hole 5 or a solvent for dissolving the modifier, a solvent supply process supplies solvent from the ground, making it possible to reliably generate the modifier solution.

In addition, in this embodiment, when the modifier solution Y is measured, the modifier solution Y is moved along the solution movement path 40. In this way, by measuring the pH value of the modifier solution Y that moves on the surface of the sensor 50 multiple times, it is possible to measure a wide range of the modifier solution Y rather than a limited range of the modifier solution Y, thereby suppressing measurement errors. In this embodiment, the pH value is measured while the modifier solution Y is moving, but the movement (flow) of the modifier solution Y may be stopped at the measurement timing, and then the movement of the modifier solution Y is resumed, and the movement (flow) of the modifier solution Y is stopped again at the next measurement timing. In addition, since the aspirated modifier solution Y is discharged to the ground, when measuring at multiple points while moving the sensor 50 in the depth direction, mixing of the modifier solution Y in the depth direction can also be suppressed, thereby improving measurement accuracy.

Furthermore, in this embodiment, since the modifier solution Y is passed through the filter 44 before being measured by the sensor 50, it is possible to prevent soil particles from colliding with and damaging the measurement surface (measurement membrane) of the sensor 50. It is also possible to reduce errors in the measurement of the pH value caused by soil particles. In addition, since the amount of soil particles entering the solution movement path 40 can be reduced, clogging of the solution movement path 40 can also be reduced.

In addition, in this embodiment, the sensor housing 22 and the imaging device housing 60 are freely separable (removable) in the insertion member 20, so the imaging device 65 can be omitted. On the other hand, when both are used simultaneously, the imaging device housing 60 is positioned on the lower side, so that the inner wall of the vertical hole 5 can be imaged over a wider range than the measurement range of the sensor 50. As a result, the cause of an abnormality in the measurement value of the sensor 50 can be reliably analyzed by visually inspecting the image.

In the above embodiment, the case where the modifier solution Y is discharged to the ground through the solution movement path 40 is illustrated, but the present invention is not limited to this. For example, as shown in FIG. 8, as a modified insertion member 20, a solution discharge hole 40E can be formed in the housing, and the other end of the solution movement path 40 can be connected to the solution discharge hole 40E. In addition, a liquid delivery means 300 such as an axial flow pump, a diaphragm pump, or a bladder pump, which serves as a solution moving means, is placed in the middle of the solution movement path 40. In this way, the modifier solution Y that flows into the buffer space 40B through the suction port 40A can be re-discharged from the solution discharge hole 40E into the vertical hole 5. The pH value may be measured multiple times by the sensor 50 while moving the modifier solution Y through such a circulation path.

Furthermore, in this embodiment, the sensor 50 and the temperature detection unit 58 are arranged in the solution movement path 40 provided inside the insertion member 20, but the present invention is not limited to this. For example, as in the modified insertion member 20 shown in Figure 9, the sensor 50 and the temperature detection unit 58 may be arranged with the detection surface exposed on the outer circumferential surface of the housing. In this way, the modifier solution Y in the vertical hole 5 can be directly measured.

At this time, as shown in FIG. 10(A), it is preferable to use the drilling device (insertion device) 10 to move the insertion member 20 up and down reciprocally at a specific depth that is the measurement point, and measure the physical property values of the modifier solution Y, etc., multiple times. In this way, the modifier solution Y and the sensor 50 can be moved relative to each other at the contact point between the sensor 50 and the modifier solution Y, etc., thereby reducing measurement errors. In other words, in this method, the drilling device (insertion device) 10 also serves as a solution moving means for moving the modifier solution Y, etc., and the sensor 50 relative to each other. Note that there is no particular limit to the vertical movement distance or movement speed of the insertion member 20.

Furthermore, in this embodiment, the sensor 50 and the temperature detection unit 58 are arranged on the side of the insertion member 20, but the present invention is not limited to this. For example, as in the soil reforming state measurement device 1 of the modified example shown in FIG. 11, a buffer tank (measurement tank) 40T may be provided on the ground side of the solution movement path 40, and the physical property value of the modifier solution Y temporarily stored in this buffer tank 40T may be measured by the sensor 50 and the temperature detection unit 58. At this time, it is preferable to measure the physical property value after sucking up the modifier solution Y at a specific depth that is the measurement point and filling the buffer tank 40T sufficiently. It is preferable that the storage amount of the buffer tank 40T is small, and the amount of the modifier solution Y that is required to be sucked up can be suppressed. The modifier solution Y that overflows from the buffer tank 40T is collected in the solution tank 42.

In this embodiment, the sensor 50 measures the pH value, but the present invention is not limited to this. For example, in the case of soil that is originally highly alkaline, the difference in pH value before and after the amendment is mixed in is small, and the measurement accuracy is likely to deteriorate. In that case, it is preferable to include a detection electrolyte that is not contained in the original soil (or is contained in a small amount) in the amendment, and to use the sensor 50 as an ion concentration meter that can detect only this detection electrolyte. In this way, the difference in the measured ion concentration before and after soil amendment becomes large, improving the measurement accuracy.

In addition, in this embodiment, the case where water (groundwater) is used as the solvent is exemplified, but the present invention is not limited to this, and a solvent other than water in which the electrolyte to be detected is easily soluble can also be used. If the modifier is a high-viscosity fluid, a solvent that reduces the viscosity may be selected.

In addition, in this embodiment, the physical properties of the modifier solution Y are measured at multiple depths while decreasing the depth (while raising the insertion member), but the present invention is not limited to this, and measurements may be performed while increasing the depth (while lowering the insertion member). In this case, it is possible to continue the measurement when each measurement depth is reached while continuing to excavate the vertical hole with the insertion member, which has the advantage of suppressing contamination of the modifier or modifier solution in the depth direction.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

1 Soil reformation state measuring device 5 Vertical hole 10 Excavation device 12 Insertion rod 20 Insertion member 22 Sensor storage section 24 Sensor side housing 30 Solvent supply path 30A Discharge port 32 Solvent tank 33 Liquid delivery pump 40 Solution movement path 40A Intake port 40B Buffer space 40E Solution discharge hole 40T Buffer tank 42 Solution tank 43 Pressure control device 44 Filter 50 Sensor 51 Sensitive electrode 52 Reference electrode 58 Temperature detection section 60 Imaging device storage section 64 Imaging device side housing 65 Imaging device 65A Imaging port 69 Tip cone 70 Control device 71 Controller 72 Detection wiring 74 Video wiring 76 Position information wiring 80 Personal computer Y Modifier solution, etc. Z Pre-modified solution

Claims (10)

A soil reforming state measurement method for measuring the diffusion state of a soil reformer introduced into the ground, comprising:
a solution transfer process for transferring the modifier accumulated in a vertical hole formed in a place where the modifier is assumed to be mixed with soil, or a modifier solution generated by dissolving the modifier in a solvent accumulated in the vertical hole;
The method further comprises a solution measurement step of measuring physical properties of the modifier or the modifier solution moved by the solution moving step.
Method for measuring soil amendment status. In the solution transfer step, the modifier or the modifier solution to be transferred is passed through a filter;
In the solution measurement step, the physical property values of the modifier or the modifier solution that has passed through the filter are measured.
The method for measuring a soil reformed state according to claim 1. The solution moving step is characterized in that the modifier or the modifier solution is moved to the ground.
The method for measuring a soil reformed state according to claim 1 or 2. In the solution measurement step, the physical property values of the modifier or the modifier solution moved to the ground are measured.
The method for measuring a soil reformed state according to claim 3. A soil reforming state measurement method for measuring the diffusion state of a soil reformer introduced into the ground, comprising:
A solution measurement process is provided for measuring the physical properties of the modifier stored in a vertical hole formed in a place where the modifier is assumed to be mixed with soil, or the physical properties of a modifier solution generated by dissolving the modifier in a solvent stored in the vertical hole;
The method is characterized in that the modifier or the modifier solution and the sensor are moved relative to each other at a contact portion between the sensor for measuring the physical property value and the modifier or the modifier solution.
Method for measuring soil amendment status. The physical property value is measured multiple times at a common depth by intervening relative movement between the modifier or the modifier solution and the sensor.
The method for measuring a soil reformed state according to claim 5. A soil reforming state measurement method for measuring the diffusion state of a soil reformer introduced into the ground, comprising:
a solvent supplying step of supplying a solvent capable of dissolving the modifier to a vertical hole formed in a place where the modifier is presumed to be mixed with soil;
A solution measurement process for measuring physical properties of a modifier solution generated by dissolving the modifier in the solvent stored inside the vertical hole.
Method for measuring soil amendment status. A soil reforming state measuring device for measuring the diffusion state of a soil reforming material impregnated into the ground,
An insertion member to be inserted into a vertical hole formed in a location where the improvement material is presumed to be mixed with soil;
a sensor disposed in the insertion member for detecting a physical property value of the modifier stored in the vertical hole or a physical property value of a modifier solution generated by dissolving the modifier in a solvent stored in the vertical hole;
a solution passage provided in the insertion member for guiding the modifier or the modifier solution;
The sensor detects a physical property value of the modifier or the modifier solution taken into the solution movement path.
Soil reformation status measuring device. The present invention is characterized in that a solution moving means is provided for moving the modifier or the modifier solution in the solution moving path.
The soil reformation state measuring device according to claim 8 . The solution transfer path is characterized in that it guides the modifier or the modifier solution to the ground.
The soil reformation state measuring device according to any one of claims 8 and 9 .

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