Method and device for managing the finished product of chemical injection

Abstract

To monitor change in a ground of a chemical penetration range before the chemical is solidified in real time immediately after injection, at the time of chemical injection in ground improvement.SOLUTION: At the time of chemical injection in ground improvement, chemical containing microbubbles and nanobubbles is injected to a ground 8, and change in amplitude of elastic waves (for example, sound waves) propagating through the ground 8 including a chemical injection part is measured immediate after the chemical injection, for example, using acoustic tomography using an oscillator 22 and a receiver 32 inserted into holes (20, 30, 31 and 16) provided in the ground 8, and a chemical penetration range (improvement body A) is monitored in real time before the chemical is solidified.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a method and device for managing the performance of chemical injection, and is particularly suitable for use in chemical injection for ground improvement work, and for monitoring changes in the ground in real time in the range of chemical injection immediately after the chemical injection and before the chemical solidifies. Continue The present invention relates to a method and device for managing the finished product of chemical injection, which makes it possible to [Background technology]

[0002] Confirmation work in chemical injection work for ground improvement is carried out to check whether the chemicals are being injected according to the results of the mix test and the injection specifications planned at the time of design. In order to perform reliable construction, it is important to understand the infiltration speed (pressure) and direction of the chemicals, and the presence or absence of silt or other difficult-to-permeate areas. However, with current confirmation boring, only the boring position information can be obtained, so detailed information such as the infiltration speed and infiltration direction cannot be obtained for ground without boring data.

[0003] As a technique for evaluating the range of injection of a drug solution, the applicant has proposed in Patent Document 1 a method for evaluating the range of injection by utilizing the fact that the amplitude attenuation rate of elastic waves increases in the range of injection of a drug solution.

[0004] Furthermore, Patent Documents 2 and 3 describe a method of measuring the longitudinal wave velocity Vp and the shear wave velocity Vs using a medicinal solution containing air bubbles (Patent Document 2) or microbubbles (Patent Document 3) in order to monitor the injection range of the medicinal solution.

[0005] On the other hand, although they are not technologies for monitoring the injection status of a chemical solution, Patent Documents 4 and 5 describe the injection of a silica solution containing fine bubbles (microbubbles) into the ground for the purpose of desaturating the ground to prevent liquefaction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-143432 A [Patent Document 2] Patent No. 6792117 (Claim 2) [Patent Document 3] Patent No. 6961270 (paragraph 0155, Figure 14) [Patent Document 4] Patent No. 5190615 [Patent Document 5] Patent No. 5092103 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the technology described in Patent Document 1, the increase in the attenuation rate occurs after the chemical solution has solidified to a certain extent (3 hours or more), so it was not possible to monitor the condition during improvement from after the chemical solution was injected until solidification.

[0008] In addition, in the technologies described in Patent Documents 2 and 3, the speed reduction due to the inclusion of microbubbles is slight, and detection is possible in model soil tanks where precise measurements are possible, but it is difficult and impractical to implement in actual sites where there is noise that affects measurement accuracy and uneven ground.

[0009] also , Patent Literature 3 to The technology described in Patent Document 5 is intended for ground improvement, and does not take into consideration monitoring the area into which the chemical solution is injected.

[0010] The present invention has been made to solve the above-mentioned problems of the conventional technology, and is capable of monitoring changes in the ground in the area where the chemical solution penetrates in real time immediately after injection before the chemical solution hardens. Can't continue The goal is to make it possible for [Means for solving the problem]

[0011] In the present invention, when injecting a chemical solution for ground improvement, a chemical solution containing microbubbles and nanobubbles is injected into the ground, and immediately after the chemical solution is injected, the change in the amplitude of the elastic wave propagating through the ground including the part where the chemical solution is injected is measured. Continue The extent of penetration of the chemical solution can be monitored in real time before the chemical solution solidifies. Can't continue R Make it so This solves the above problems.

[0012] The present invention also provides a performance management device for chemical injection in ground improvement, comprising a means for generating a chemical solution containing microbubbles and nanobubbles, a means for injecting the chemical solution containing microbubbles and nanobubbles into the ground, and a measuring device for measuring a change in the amplitude of elastic waves propagating through the ground including the part where the chemical solution was injected, immediately after the chemical solution was injected. Continue The system is equipped with a means to monitor the extent of penetration of the chemical solution in real time before the chemical solution solidifies. It is designed to be able to continue The above-mentioned problems are also solved by a chemical injection form management device, which is characterized by the above.

[0013] Here, the change in amplitude can be measured using the technique of acoustic tomography, which uses an oscillator and a receiver inserted in a hole in the ground.

[0014] Furthermore, the hole for inserting the oscillator or the receiver can be an injection hole for a drug solution.

[0015] In addition, by using the results of the laboratory tests as a calibration, the range of penetration of the chemical solution can be determined from the distribution of the amplitude attenuation rate, and the improvement rate and ground strength can be estimated.

[0016] In addition, a threshold value is set based on the results of laboratory tests, and when the change in amplitude exceeds this threshold value, it is automatically detected, making it possible to grasp the extent of chemical penetration. Effect of the Invention

[0017] According to the present invention, changes in the ground in the area where the chemical solution penetrates before the chemical solution solidifies can be monitored in real time immediately after injection. Continue It becomes possible to do so. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view showing the overall configuration of an embodiment of the present invention, including a partial block diagram. [Diagram 2] FIG. 1 is a cross-sectional view showing an example of a state immediately after starting injection in an embodiment of the present invention. [Diagram 3] A cross-sectional view showing an example of an assumed improved diameter of 25% [Figure 4] A cross-sectional view showing an example of the assumed improved diameter of 50% [Diagram 5] FIG. 11 is a cross-sectional view showing an example of the state at the time of completion of injection. [Figure 6] FIG. 1 is a diagram showing a comparison of (A) the change in velocity from the initial value and (B) the change in amplitude from the initial value when a medicinal solution containing microbubbles and nanobubbles is injected according to an embodiment of the present invention. [Figure 7] A graph showing the change in amplitude to show the effect of mixing microbubbles and nanobubbles. [Figure 8] The same diagram showing the change in speed [Figure 9] A diagram showing the detection range. [Figure 10] A graph showing (A) the change in velocity from the initial value and (B) the change in amplitude from the initial value when a drug solution containing no microbubbles or no nanobubbles is injected as a comparative example of the present invention. [Figure 11] FIG. 1 is a perspective view showing an example of the arrangement of an underground injection hole, an oscillator measurement hole, and a receiver measurement hole in an embodiment of the present invention. [Figure 12] Also floor plan [Figure 13] A diagram showing an example of how to perform real-time visualization processing. [Figure 14] Diagram showing an example of the relationship between damping rate and unconfined compressive strength [Figure 15] Diagram showing an example of (A) damping rate distribution diagram and (B) uniaxial compressive strength distribution diagram [Figure 16] 1A and 1B are cross-sectional views showing a state in which (A) the permeation rate, (B) the permeation direction, and (C) a poorly permeable layer are detected in an embodiment of the present invention. [Figure 17] A flow chart showing an example of a procedure for performing completed form management using the present invention. [Figure 18] FIG. 1 is a perspective view showing another embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the contents described in the following embodiments and examples. In addition, the constituent elements in the embodiments and examples described below include those that a person skilled in the art can easily imagine, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the constituent elements disclosed in the embodiments and examples described below may be appropriately combined or appropriately selected for use.

[0020] As shown in the overall configuration of FIG. 1, an embodiment of the present invention is a form management device for chemical injection in ground improvement work, and includes a chemical supply device 10, a bubble water supply device 12, and a mixer 14, which are means for generating a chemical solution containing microbubbles and nanobubbles, an injection hole 16, which is a means for injecting the chemical solution containing microbubbles and nanobubbles into the ground 8, an oscillator circuit 18, which is a means for measuring the change in amplitude of elastic waves propagating through the ground 8 including the part where the chemical solution is injected using acoustic tomography technology immediately after the chemical solution is injected, an oscillator 22 inserted into an oscillator measurement hole (also referred to as an oscillator hole) 20, a receiver 32 inserted into a receiver measurement hole (also referred to as a receiving hole) 30, a receiving circuit 34, and a personal computer 40, and is configured to monitor the range of chemical solution penetration in real time before the chemical solution solidifies.

[0021] The elastic wave may be, for example, a multi-oscillating sound wave combining a pseudo-random signal and amplitude modulation, the oscillator circuit 18 may be, for example, an oscillator signal amplifier, the oscillator 22 may be, for example, an underwater speaker, the receiver 32 may be, for example, an underwater microphone, the receiving circuit 34 may be, for example, a receiving signal filter, and the personal computer 40 may be, for example, a data logger.

[0022] Moreover, the oscillator circuit 18, the personal computer 40, and the receiving circuit 34 are capable of communicating with each other via a communication device (not shown) in a wired or wireless manner.

[0023] The chemical supplied by the chemical supply device 10 can be, for example, a special silica-based (permanent grout) such as solution-type activated silica, but the type of chemical is not limited thereto.

[0024] The size of the microbubbles is, for example, 1 μm to 100 μm in diameter, and the size of the nanobubbles is, for example, 0.0001 μm to 1 μm in diameter, but the sizes of the microbubbles and nanobubbles are not limited to these.

[0025] Figure 2 shows the state immediately after starting chemical injection, Figure 3 shows the state when the assumed improved diameter is 25%, Figure 4 shows the state when the assumed improved diameter is 50%, and Figure 5 shows the state when injection is completed. The thin and thick lines in the figures show the wavy lines of sound waves, but the thick lines show the wavy lines affected by improved body A, which corresponds to the range of chemical penetration. As improved body A becomes larger, the number of wavy lines affected by improved body A increases, so by monitoring this, the size of improved body A can be ascertained.

[0026] Figure 6 shows an example of measuring the change in sound wave velocity from the initial value (A) and the change in sound wave amplitude from the initial value (B) at intervals of 1 to 10 minutes after injecting a chemical solution containing microbubbles and nanobubbles into the ground 8. Injection took 60 minutes, and measurements continued from the start of injection until 140 minutes had elapsed. A in Figure 6 represents the improved body at the end of injection. As is clear from Figure 6(A), the velocity hardly changes for either the wavy line B of oscillation 1-reception 1 crossing the improved body A, or the wavy line C of oscillation 2-reception 2 not crossing the improved body A. In contrast, as is clear from Figure 6(B), the amplitude hardly changes for the wavy line C of oscillation 2-reception 2 not crossing the improved body A, while the wavy line B of oscillation 1-reception 1 crossing the improved body A gradually becomes smaller as the improved body A becomes larger.

[0027] Therefore, by measuring the change in amplitude when a medicinal solution containing microbubbles and nanobubbles is injected, the extent of caking of improved body A can be detected.

[0028] In order to investigate the effect of microbubbles and nanobubbles on sound propagation, a tank filled with tap water was filled with water containing microbubbles MB, which are bubbles with diameters of 1 μm to 100 μm, and nanobubbles NB, which are bubbles with diameters of 0.0001 μm to 1 μm. The results of measuring the amplitude using oscillator 22 and receiver 32 are shown in Figure 7, and the results of measuring the velocity are shown in Figure 8.

[0029] As is clear from Figure 7, the amplitude is greatly reduced (maximum change of 40 dB (1 / 100)) by injecting water containing microbubbles MB and nanobubbles NB, and then recovers as the microbubbles MB decrease, but this state of being reduced to about 20 dB (1 / 10) due to the remaining nanobubbles NB continues until the nanobubbles NB decrease and the water is replaced with tap water that does not contain microbubbles MB or nanobubbles NB. In contrast, as is clear from Figure 8, the velocity is slightly reduced (maximum change of 4%) by injecting water containing microbubbles MB and nanobubbles NB, but recovers to its original state as the microbubbles MB decrease, indicating that the nanobubbles NB do not have a significant effect on the velocity.

[0030] The effect of mixing microbubbles and nanobubbles into a liquid medicine is shown in Figure 9. Conventionally, it was only possible to detect a problem from the start of injection of the liquid medicine until the injection was almost completed, but according to the present invention, it is possible to detect a problem at an early stage after the start of injection, and it is also possible to, for example, redo the injection at an early stage.

[0031] On the other hand, as a reference example, when a chemical solution containing neither microbubbles nor nanobubbles is injected into the ground 8, as shown in FIG. 10, there is almost no change in either (A) the velocity from the initial value or (B) the amplitude from the initial value.

[0032] An example of the arrangement during actual measurement is shown in Fig. 11. Surrounding the injection hole 16 are an oscillation hole 20 into which an oscillator 22 is inserted, and a receiving hole 30 into which a receiver 32 is inserted.

[0033] Examples of the planar arrangement of the oscillation hole 20 and the receiving hole 30 are shown in FIGS. 12(A), 12(B), and 12(C).

[0034] In Figure 12(A), a wavy line generated from an oscillator 22 inserted into an oscillation hole 20 on one side of an injection hole 16 (the upper side in the figure) is detected by receivers 32 placed in three receiving holes 30 located on the opposite side of the injection hole 16 (the lower side in the figure).

[0035] In Figure 12(B), wavy lines generated by oscillators 22 inserted into the three oscillation holes 20 at the top of the figure are detected by receivers 32 placed in the three receiving holes 30 located at the bottom of the figure.

[0036] In Figure 12(C), in addition to Figure 12(A), a wavy line generated by oscillator 22 in oscillation hole 20 located on one side (left side in the figure) in line with injection hole 16 is detected by receiver 32 in receiving hole 30 located on the opposite side (right side in the figure) in line with injection hole 16.

[0037] It should be noted that FIG. 12 is merely an example, and for example, an arrangement in which the oscillation hole 20 and the reception hole 30 are interchanged or other arrangements are also possible.

[0038] Furthermore, it is also possible to perform acoustic tomography by utilizing the injection holes 16 provided in the ground 8 at intervals of, for example, about 2 m for injecting chemicals, and placing the oscillator 22 and receiver 32 in them. In this case, there is no need to provide separate oscillator holes 20 and receiver holes 30, and measurements can be easily performed.

[0039] An example of a method for performing real-time visualization processing based on amplitude changes is shown in FIG.

[0040] In step 100, oscillators 22-1 to 22-N in the oscillation holes are caused to oscillate sequentially, and the amplitudes in each wavy line path are sequentially read, for example, by receivers 32-1 to 32-N in two receiving holes 1 and receivers 33-1 to 33-N in receiving hole 2, and these are set as the initial values ​​at 0 minutes.

[0041] Similarly, in step 110, the amplitude of each wavy line path after the current time T minutes has elapsed is read in sequence.

[0042] Then, in step 120, the difference from the initial value is calculated to eliminate the effects of noise, and is obtained as the amount of change.

[0043] Next, proceeding to step 130, divide the cross section into cells, and if the cells where the amount of change in amplitude exceeds a threshold and the number of wavy lines exceeds a predetermined number are determined to be cells where the drug solution has penetrated and are colored, the improved body A corresponding to the range of drug solution penetration after T minutes has elapsed can be displayed and visualized in real time. Furthermore, if the colored cells after t1, t2, ..., t5 minutes are displayed in different colors or densities, the formation progress of improved body A can be displayed and visualized in real time from the changes in the colored cells.

[0044] Proceeding further to step 140, a tomography analysis is performed to generate a distribution map of the amplitude attenuation rate, thereby allowing the intensity distribution to be calculated.

[0045] In addition, the equation q, which shows the relationship between the amplitude attenuation rate and the unconfined compressive strength as shown in Figure 14, u The parameters a and b (which vary depending on conditions) are experimentally determined, and the damping rate distribution diagram shown in FIG. 15(A) is converted into the uniaxial compressive strength distribution diagram shown in FIG. 15(B), thereby making it possible to know the distribution of compressive strength.

[0046] In this way, the range of penetration of the chemical solution can be determined from the change in the amplitude attenuation rate, and the improvement rate and ground strength can be estimated based on the results of confirmation work and indoor tests.

[0047] An image of a measurement example is shown in Figure 16. As shown in Figure 16(A), the permeation rate can be determined from the change in shape of improved body A that corresponds to the range of chemical solution permeation. Also, as shown in Figure 16(B), the permeation direction can be determined from the change in shape of improved body A. Furthermore, as shown in Figure 16(C), the difficult-to-permeate layer can be determined from the change in shape of improved body A.

[0048] FIG. 17 shows the procedure for performing as-built management using the present invention.

[0049] After a boring survey is carried out in step 200, the area of ​​ground improvement is designed in step 210, and the injection hole 16 is excavated in step 220.

[0050] Next, in step 230, a chemical solution containing microbubbles and nanobubbles according to the present invention is injected into the ground 8 through the injection hole 16, while in step 240, the shape of the improved body A is investigated by physical exploration such as amplitude attenuation tomography, and the injection and solidification status based on the properties of the ground to be injected is accurately grasped.

[0051] Next, in step 250, the chemical injection conditions are reviewed taking into account the above situation to ensure reliable improvement. If there is no need to review the chemical injection conditions, proceed to step 260. For example, if the improvement mass spreads unevenly, it is assumed that the ground has been fractured by the injection pressure, so the injection rate is reduced. If the chemical solution spreads while dripping, it is assumed that the permeability of the ground is higher than previously assumed, so the gel time is shortened. If the chemical solution is spreading due to the influence of groundwater flow, it is possible to inject the chemical solution upstream of the groundwater flow in advance to create a wall.

[0052] Next, in step 260, a chemical solution containing microbubbles and nanobubbles according to the present invention is injected into the ground 8 through the injection hole 16, while in step 270, the shape of the improved body A is grasped by, for example, the amount of chemical solution injected and a boring survey, physical exploration such as amplitude attenuation tomography, etc., to grasp the exact finished shape and ensure peace of mind and safety after construction.

[0053] In this embodiment, a multiple oscillation sound wave that combines a pseudorandom signal and amplitude modulation is used as the elastic wave propagating through the ground 8, so that accurate measurement that is less susceptible to the effects of noise is possible. Note that the type of elastic wave is not limited to this, and for example, the amplitude modulation can be omitted.

[0054] In the above embodiment, the drug supplied from drug supply device 10 and the bubbled water supplied from bubble water supply device 12 are mixed in mixer 14 to produce a drug solution containing microbubbles and nanobubbles. However, the method of producing a drug solution containing microbubbles and nanobubbles is not limited to this. For example, a nozzle having fine holes formed therein may be disposed on the outlet side of drug supply device 10 to directly produce a drug solution containing microbubbles and nanobubbles.

[0055] In addition, in the above embodiment, the oscillators 22 in the oscillation hole 20 are oscillated sequentially, but as in another embodiment shown in Figure 18, it is also possible to perform rapid measurement by oscillating multiple (10 in the figure) oscillators 22-1 to 22-10 simultaneously and receiving the signals simultaneously with multiple (10 in the figure) receivers 32-1 to 32-10, 33-1 to 33-10 provided in multiple receiving holes 30, 31 (three or more are also acceptable).

[0056] The technique used to detect the attenuation of the amplitude of the elastic wave is not limited to acoustic tomography, and the measurement may be intermittent rather than continuous. [Explanation of symbols]

[0057] 8...Ground 10. Drug supply device 12…Bubble water supply device 14…Mixer 16...Injection hole 18...Oscillation circuit 20...Oscillator measurement hole (oscillating hole) 22, 22-1 to 22-10...Oscillator 30, 31... Receiver measurement holes (receiving holes) 32, 32-1~32-10, 33-1~33-10...Receiver 34…Receiver circuit 40…PC A…Improved body (drug solution penetration range)

Claims

1. When injecting chemicals for ground improvement, A chemical solution containing microbubbles and nanobubbles is injected into the ground, Immediately after the injection, the change in the amplitude of the elastic waves propagating through the ground, including the injected area, was continuously measured. This method for managing the finished product of chemical injection is characterized in that it enables the range of chemical penetration to be continuously monitored in real time even before the chemical solidifies.

2. 2. The method for managing the performance of chemical injection according to claim 1, characterized in that the change in amplitude is measured using acoustic tomography technology that uses an oscillator and a receiver inserted into a hole in the ground.

3. 3. The method for managing the finished product of chemical injection according to claim 2, wherein a chemical injection hole is used as the hole for inserting the oscillator or the receiver.

4. A method for managing the finished product of chemical injection as described in any one of claims 1 to 3, characterized in that the results of indoor tests are used as calibration to grasp the range of chemical infiltration from the distribution of the amplitude attenuation rate, and the improvement rate and ground strength are estimated.

5. The method for managing the finished product of chemical injection as described in claim 1, characterized in that a threshold value is set based on the results of indoor tests, and when the change in amplitude exceeds this threshold value, it is automatically detected, and the range of chemical penetration is grasped.

6. A performance management device for chemical injection in ground improvement work, A means for generating a medicinal solution containing microbubbles and nanobubbles; A means for injecting a chemical solution containing the microbubbles and nanobubbles into the ground; and a means for continuously measuring a change in the amplitude of an elastic wave propagating through the ground including the portion where the chemical solution is injected, from immediately after the chemical solution is injected; This is a chemical injection form management device that is characterized in that it is capable of continuously monitoring the range of chemical penetration in real time from before the chemical solidifies.

7. The chemical injection performance management device according to claim 6, characterized in that the change in amplitude is measured using acoustic tomography technology that uses an oscillator and a receiver inserted into a hole in the ground.

8. 8. The device for managing the performance of chemical injection according to claim 7, characterized in that a chemical injection hole is used as the hole for inserting the oscillator or the receiver.

9. A chemical injection performance management device as described in any one of claims 6 to 8, characterized in that the results of indoor tests are used as calibration to determine the range of chemical infiltration from the distribution of the amplitude attenuation rate, and the improvement rate and ground strength are estimated.

10. The chemical injection performance management device described in claim 6, characterized in that a threshold value is set based on the results of indoor tests, and when the change in amplitude exceeds this threshold value, it is automatically detected, and the range of chemical penetration is grasped.

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