Visual tracing method for soil reinforcement and simulation device

Abstract

The invention relates to the technical field of soil body reinforcement visual construction, and discloses a soil body reinforcement visual tracing method and a simulation device. The technical problems that in the prior art, a traditional soil body reinforcement detection method is large in destructiveness and high in cost, continuous tracing detection cannot be achieved, and the diffusion range, flow distribution and reinforcement effect judgment of a reinforcement material in a soil body cannot be visually known are solved. The visual tracing method for soil reinforcement comprises the following steps: (1) arranging an exciting electrode array; (2) excitation electrode discharge measurement; (3) measuring potential difference; (4) calculating the resistivity; and (5) geologic body response judgment. By means of excitation current real-time monitoring, accurate defect position positioning, dynamic reinforcement parameter optimization, three-dimensional visual tracing and the like, the quality of a soil body reinforcement project can be judged, and the safety of project implementation is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of soil reinforcement visualization construction, and in particular to a soil reinforcement visualization tracing method and a simulation device. Background Art

[0002] In engineering construction, such as building foundation construction, slope management, and underground excavation, soil stability is a critical factor in ensuring project safety and quality. Most natural soils, due to characteristics such as insufficient strength, fail to meet technical requirements and therefore require reinforcement. For example, unreinforced soil in high-rise buildings can lead to settlement and cracking; unreinforced soil in slopes is prone to landslides and collapses, posing a safety hazard. During soil reinforcement, real-time and intuitive understanding of the diffusion range, distribution uniformity, and reinforcement effectiveness of reinforcement materials is crucial for optimizing construction parameters and improving reinforcement quality. Failure to monitor slurry diffusion in real time can easily lead to localized under- or over-grouting, which not only weakens the reinforcement effect but can also lead to secondary engineering problems. Traditional soil reinforcement testing methods are highly destructive and costly, lack continuous tracing testing, and lack the ability to intuitively understand the diffusion range, flow distribution, and reinforcement effectiveness of reinforcement materials within the soil.

[0003] Prior art Chinese patent document 202411584612.X discloses an automated proportioning method and device for conductive grouting tracer materials. This method aims to address the existing technical problem of a lack of automated design methods for conductive tracer proportioning during foundation pit grouting reinforcement, resulting in poor electrical resistivity tomography (ERT) results. The invention includes the following steps: data acquisition and collection; parameter setting and construction plan development; grouting proportion control and construction measure determination; automated proportion generation and output; and automated real-time feedback and correction.

[0004] However, the implementation of the above-mentioned scheme presents at least the following technical challenges: Traditional soil reinforcement methods lack effective real-time monitoring during construction, making it impossible to intuitively understand the diffusion range, distribution uniformity, and reinforcement effectiveness of the reinforcement material within the soil. This can lead to uneven reinforcement results, and under complex geological conditions, it is difficult to accurately locate abnormal areas, resulting in ineffective reinforcement measures targeting problem areas and difficulties in optimizing construction parameters. Therefore, a method and device for visually tracing soil reinforcement is urgently needed. This method, which can accurately and real-timely reflect the distribution of reinforcement materials within the soil and the reinforcement effect, is of great practical significance for improving the quality and efficiency of soil reinforcement projects. It not only provides intuitive guidance for construction personnel, helping them to adjust construction parameters in a timely manner to ensure uniform distribution and effective diffusion of reinforcement materials, but also provides reliable technical support for project supervision and quality inspection, reducing project risks and ensuring the safety and reliability of construction. Summary of the Invention

[0005] In view of the above technical problems, the present disclosure provides a method and device for visual implementation of soil reinforcement tracing, which solves the technical problem that traditional soil reinforcement methods in the existing technology lack effective real-time monitoring means during the construction process, and cannot intuitively understand the diffusion range, distribution uniformity and reinforcement effect of the reinforcement material in the soil.

[0006] According to one aspect of the present disclosure, a soil reinforcement visualization tracing method is provided, comprising the following steps: S1: Excitation electrode array layout: Electrode arrays are laid out on the surface and in underground boreholes within the soil mass encompassing the survey area; S2: Excitation electrode discharge measurement: Using the prepared conductive tracer material, during the grouting process, direct current or low-frequency alternating current with a current of I is injected into the ground through the excitation electrode to form an artificial electric field in the underground medium; S3: Potential difference measurement: During the grouting process, while the current is injected into the excitation electrode, the potential difference at any point in the electrode array is measured. ; S4: Calculate the resistivity: The resistivity of any point in the electrode array: , where: Adjustment factors for test fixtures; is the potential difference between the measured electrodes; I is the supply current; S5: Geological body response judgment: The geological body response is judged by the difference in resistivity. When the geological body is dry, hollow or unfilled, it hinders the passage of current and appears as high resistance. When it is water-filled, hollow or water-rich, a path is formed to converge current, which appears as low resistance anomaly.

[0007] According to another aspect of the present disclosure, a method for preparing a conductive tracer material is provided for detecting the flow of soil slurry during grouting to understand the diffusion range, flow distribution, and reinforcement effect of the reinforcement material in the soil, including the following steps: S1: Dry mixing: cement and fly ash are dry mixed; S2: Preparation of dispersion: After the graphite powder is mixed with the dispersant and water, tributyl phosphate is added to the dispersion and the mixture is thoroughly mixed by high-speed stirring to form a dispersion; S3: Tracer material: dry-mixed cement and fly ash are wet-mixed with the dispersion prepared above in a cement-sand mixer to obtain a tracer material; S4: Testing: The prepared tracer material is subjected to flowability test, water extraction rate test, and viscosity test.

[0008] In some embodiments of the present disclosure, the conductive tracer material is prepared for fluidity testing using an extended cone flow test plate and a rheometer. The grouting material is poured into the fluid mold material, and its diffusion diameter is measured after it flows out naturally to evaluate the material fluidity.

[0009] In some embodiments of the present disclosure, the water leaching rate test of the conductive tracer material is performed using a glass plate and a standard container; the water leaching rate is calculated by comparing the height difference between the initial and final states of the conductive tracer material after standing.

[0010] In some embodiments of the present disclosure, the viscosity test of the conductive tracer material is mainly performed using a Marshall funnel and a standard cup test, and the viscosity of the material is evaluated based on the time it takes for the material to flow into the standard cup.

[0011] In some embodiments of the present disclosure, the resistivity of the conductive tracer material is dynamically monitored during the curing period, and the time-varying dynamic monitoring results of the resistivity are fitted to obtain a relationship between the resistivity and the curing age that satisfies the following functional relationship: ; Where, ρ is the test resistivity of the grouting slurry, unit: Ω·cm, t For the maintenance age, t 0. ρ 1 、 ρ 2 are fitting parameters, among which ρ 1 、 ρ 2 They can indirectly reflect the initial monitoring stage and final state impedance of the material. t 0 reflects the time point when the resistivity of the tracer material increases fastest, p is the control parameter related to the time-varying properties of the material.

[0012] According to another aspect of the present disclosure, a conductive tracer material flexural strength test device is provided, which is suitable for the above-mentioned method for preparing the conductive tracer material and is used for testing the mechanical properties of the tracer material. The device comprises an upper loading plate and a lower loading plate. Pressure is applied above the upper loading plate by a hydraulic rod. A spirit level is provided above the upper loading plate to ensure that it remains horizontal when pressure is applied. The upper loading plate is connected to an upper fixture back plate through a force transmission rod below the upper loading plate. A lower fixture back plate is provided above the lower loading plate. A flexural test loading rod is accommodated between the upper and lower fixture back plates to contact the slurry sample.

[0013] In some embodiments of the present disclosure, in the geological body response of step S5, the moisture content of the soil, the relative resistivity of the soil, and the imaging field average all satisfy the following functional relationship: ; In the formula R is the test relative resistance of the soil, is the sensitive field characteristic value, a 0 、 b 0 、 c 0 are fitting parameters, ω is the soil moisture content.

[0014] According to another aspect of the present disclosure, a soil reinforcement visualization tracing simulation device is provided, which is suitable for the above-mentioned soil reinforcement visualization tracing method. The device includes a spring electrode group surrounding a specimen. The spring electrode group is arranged in a multi-layer structure along the longitudinal direction to obtain the cross-sectional resistivity at different heights of the specimen to form a three-dimensional measurement network. The spring electrode group is connected to an acquisition control unit for acquiring the excitation and response voltages of the multi-layer electrodes. The acquisition control unit is connected to a data processing unit, which fuses the multi-layer resistivity data based on an interpolation algorithm to reconstruct a complete three-dimensional resistivity distribution image inside the specimen.

[0015] The beneficial effects of the present invention are:

[0016] By deploying an electrode array and performing potential measurements, combined with resistivity calculations, the diffusion and distribution of tracer materials in the soil can be monitored in real time, generating an intuitive three-dimensional resistivity distribution image. This visualization technology enables construction personnel to observe the injection effect of reinforcement materials in real time during the reinforcement process, promptly identifying problems such as uneven grouting and insufficient diffusion, thereby optimizing construction parameters and ensuring uniform distribution of the reinforcement material. Based on the geological response, abnormal areas in the soil, such as voids, cracks, and water-rich areas, can be precisely located, providing accurate target locations for subsequent reinforcement treatments, avoiding blind construction and improving the targeted and effective nature of the reinforcement. During the construction process, through real-time monitoring and visual feedback, construction personnel can promptly adjust construction parameters such as grouting pressure, grouting speed, and grouting volume based on the diffusion of the tracer material and changes in soil resistivity, ensuring that the reinforcement material fully fills the soil pores and achieves the desired reinforcement effect. This effectively avoids the problems of uneven reinforcement and poor reinforcement results caused by fixed construction parameters in traditional reinforcement methods. Precise reinforcement treatments and optimized construction techniques can significantly improve soil strength and stability, reduce the incidence of engineering accidents such as soil deformation and landslides, and thus extend the project's service life and reduce subsequent maintenance costs and risks. Traditional reinforcement methods, due to a lack of effective monitoring, often require numerous trials and adjustments to achieve the desired reinforcement results. This not only increases construction time and costs but can also cause project delays. This technology, through real-time monitoring and visual feedback, can quickly determine optimal construction parameters, reducing trial and error during the construction process, thereby shortening the construction period and reducing labor and material costs. During the grouting reinforcement process, precise control of the grouting range and volume avoids the material waste associated with uneven or excessive grouting, which is common with traditional grouting methods. This not only reduces the use of reinforcement materials and material costs, but also minimizes environmental impact, aligning with the concept of green construction. In complex geological conditions or underground projects, such as caverns and tunnels, traditional reinforcement methods can pose certain construction risks, such as excessive grouting pressure leading to soil rupture and groundwater intrusion. This application can effectively avoid these construction risks, ensure the safety of the construction process, and protect the safety of construction workers and the surrounding environment by real-time monitoring and precise control of the grouting process. Micron graphite fly ash composite cement-based grouting tracer material is used. This material not only has good mechanical properties and fluidity, but is also environmentally friendly. As an industrial waste residue, the reuse of fly ash reduces the exploitation of natural resources and meets the requirements of sustainable development. At the same time, through precise grouting and material dosage control, the pollution of groundwater resources and damage to the surrounding ecological environment are reduced. Through dynamic monitoring and fitting analysis of resistivity throughout the entire maintenance cycle, the relationship between the resistivity of the tracer material and the curing age can be obtained, providing a scientific basis for engineering design.Designers can rationally determine the curing time and strength development patterns of reinforcement materials, optimize project design solutions, and ensure that reinforcement results meet project requirements. During construction, real-time monitoring and visual feedback enable timely identification of quality issues, such as uneven grouting and poor reinforcement results, and the implementation of appropriate remedial measures. This real-time quality control approach effectively ensures the quality of reinforcement projects, reduces engineering accidents and economic losses caused by quality issues, and provides reliable technical support for project quality acceptance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the tracer device for visual implementation of soil reinforcement; Figure 2 Another perspective structural diagram of the tracer device for soil reinforcement visualization; Figure 3 This is the structural diagram of the flexural strength test device; Figure 4 This is a structural schematic diagram of the flexural strength test device from another perspective; Figure 5 This is a comparison chart of high-precision algorithm imaging effects; Figure 5 It is divided into four parts: upper left, upper right, lower left, and lower right. Each part has a model of a different shape. The top row contains the model names, including GN_one_step, PDIPM, TSVD, and CG. The left side shows the geometric shapes input by the model, and the right side shows the reconstruction and recognition results of these shapes by each model. Figure 6 Comparison chart of prediction time for different algorithms; Figure 6 prediction time is the prediction time; Figure 7 is the three-dimensional imaging result diagram; Figure 7 The left side of the middle image shows multiple two-dimensional cross-sectional resistivities, and the right side shows a three-dimensional resistivity distribution image. Figure 8 This is the outdoor system stability test diagram; Outdoor multi-scale tests at 0.4×0.4m, 0.5×0.5m, 1×1m, and 3×3m were conducted to verify the stability and feasibility of the high-power tomography equipment. In the large-scale tests, the inversion images clearly showed the distribution of voids, with significant and stable differences from the background field, which helped to determine leakage and grouting conditions. Figure 9 This is a stability test chart in the same scenario; A stability analysis was conducted on a 1m×1m square field. The excitation electrode sequence signals were measured multiple times in the same scenario to obtain a potential difference curve. Image inversion was then performed based on the potential difference distribution. Comparative analysis showed that the potential difference signals automatically collected by the device and the images reconstructed using the inversion algorithm were essentially consistent in the same scenario, demonstrating stability. Figure 10 It is the flow solute migration detection diagram; Figure 10 The Experiment model in the left column is the experimental model, showing the percolation process in four different states (2nd, 15th, 24th, and 33th). The right column shows the results of processing the experimental model using five different processing methods (1D-CNN (tanh), GN_one_step, PDIPM, TSVD, and CG). Figure 11 This is the result diagram of the extreme difference in fluidity of the tracer material; Figure 11 The vertical axes of the three sub-graphs are the changing trends of concrete fluidity, water extraction rate, and slurry viscosity, respectively. The horizontal axes of the three sub-graphs are the same, representing different material ratios. From left to right, the black, red, blue, and purple colors represent the percentages of W / S (water-binder ratio), fly ash, graphite, and superplasticizer, respectively. Figure 12 This is the result diagram of flexural strength test and range analysis; Figure 12 The middle vertical axis, Flexural Strength, is the flexural strength in MPa. The horizontal axis, Sample Number, on the left side of the chart is the sample number. The horizontal axes of the right side of the chart represent W / C (water-cement ratio), FA% (fly ash percentage), MG% (mineral admixture percentage), and SP% (admixture percentage). Blue represents the test results after 3 days (3d), black represents the test results after 7 days (7d), and red represents the test results after 28 days (28d). Figure 13 This is the result diagram of compressive strength test and range analysis; Figure 13The horizontal axis of the middle left graph is Sample number, and the vertical axis is Compression test results. Red represents Results by 3 days (3-day test results); black represents Results by 7 days (7-day test results); and blue represents Results by 28 days (28-day test results). The right-hand graph is divided into four small areas, each showing the relationship between compressive strength and different parameters: W / C (water-cement ratio), FA (%) (fly ash), MG (%) (slag powder), and SP (%) (admixture). Figure 14 This is the time-varying characteristic diagram of the resistivity of the grouting slurry during the 28-day curing age; Figure 14 The horizontal axis represents time, the vertical axis represents resistivity, the experimental data points are marked with red squares, and the blue solid line is the fitting curve of the experimental data points. 2 is the goodness of fit; Figure 15 Reference values ​​of background field and interference field and imaging effect diagram for newly made tracer materials; Figure 15 In section (a), the X-axis shows the electrode testing sequence, and the Y-axis shows the background field test value. The blue circles represent background field values, and the red circles represent interference field values. Section (b) is titled "Nominal conductivity." Figure 16 The test results of impedance and sensitive field characteristic value under different soil moisture contents are shown in the figure; Figure 16 The X-axis represents soil moisture content, the left side of the Y-axis represents relative resistance, and the right side of the Y-axis represents imaging field average. The blue dots (Relative resistance) represent the actual measured values ​​of relative resistance; the blue dotted line (Fit of relative resistance) represents the fitted curve of relative resistance; the red dots (Imaging field average) represent the actual measured values ​​of imaging field average; and the red dotted line (Fit of imaging field average) represents the fitted curve of imaging field average. Figure 17 The inversion imaging diagram of foreign matter embedment under different soil moisture contents; Figure 17 The X-axis represents the average imagining field value; the Y-axis represents the relative resistance. The data points are represented by blue squares (labeled "R-Φ") to indicate the relationship between the actual measured relative resistance and the average imagining field value. The fit curve is represented by a red dashed line. The illustration in the lower right corner of the main figure zooms in on a section of the data in the main figure. Figure 18 Collect voltage distribution and imaging results for different excavation depths; Figure 18 The horizontal axis of the left chart is Acquisition sequences, and the vertical axis is Voltage reference value. Legend: Background: black dots represent the voltage reference value when there is no hole. Hole-2.5cm, Hole-5cm, Hole-7.5cm, Hole-10cm, Hole-15cm: red, orange, green, blue and purple dots represent the voltage reference values ​​when there are holes at different depths (2.5cm, 5cm, 7.5cm, 10cm, 15cm). The x-axis of the right chart is x / cm, indicating the horizontal position, the y-axis is y / cm, indicating the vertical position, and the z-axis is Depth / cm, indicating the depth. The color bar shows the range of voltage values. Figure 19 The distribution results of characteristic values ​​of sensitive fields at different excavation depths are shown in the figure. Figure 19 The horizontal axis represents the cavity depth, the vertical axis represents the imaging field average value, and the blue triangle data points are Φ relationship with D p Represents the relationship between the actual measured imaging field average value and the cavity depth. The red straight line: fitted curves is the curve obtained by fitting the blue data points. Figure 20 The sensitivity field response results for different excavation widths are shown; Figure 20 It consists of five small pictures, each of which represents a different excavation depth (D2.5, D5, D7.5, D12.5, D15). The titles are all Nominal conductivity; Figure 21The distribution results of characteristic values ​​of sensitive fields with different excavation widths are shown in the figure. Figure 21 The horizontal axis represents the aperture diameter, the vertical axis represents the imaging field average value, and the data points are marked with red circles. h : Represents the relationship between the average value of the imaging field and the aperture diameter. The fitting curve is represented by a black solid line. Fitted curves: represents the fitting curve, which is the curve obtained by fitting the data points. The left and right areas are divided into: Non-imaging area (None Imaging section): marked with a light yellow background, Imaging area (Imaging section): marked with a light blue background, Figure 22 This is a comparison chart of grouting performance test between tracer material and ordinary material; Figure 22 Each group of heat maps at the bottom contains four sub-maps (a) 0d, (b) 1d, (c) 2d, and (d) 3d, showing the distribution of slurry in the medium at different time points (0 day, 1 day, 2 days, and 3 days). The color of the heat map changes from blue to red to indicate the change in conductivity. The red area indicates higher conductivity, and the blue area indicates lower conductivity. The four heat maps on the left (ordinary slurry): As time increases (from 0 day to 3 days), the red area gradually expands, indicating the diffusion of ordinary slurry in the medium. The four heat maps on the right (tracer slurry): Compared with ordinary slurry, the diffusion range and speed of tracer slurry are different. Figure 23 A diagram showing the concept of building a 3D image model for 2D image slicing; Figure 23 The sub-image below shows multiple 2D image slices in the depth direction, which are then used to construct a 3D image model. The names of the components in the figure are: 1. Spring electrode group; 2. Spring electrode; 3. Upper loading plate; 4. Lower loading plate; 5. Hydraulic rod; 6. Level; 7. Force transmission rod; 8. Upper fixture back plate; 9. Lower fixture back plate; 10. Flexural test loading rod; 11. Slurry sample. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] A soil reinforcement visualization tracing method is provided, comprising the following steps: S1: Excitation electrode array layout: Electrode arrays are laid out on the surface and in underground boreholes within the soil mass encompassing the survey area; S2: Excitation electrode discharge measurement: Using the prepared conductive tracer material, during the grouting process, direct current or low-frequency alternating current with a current of I is injected into the ground through the excitation electrode to form an artificial electric field in the underground medium; S3: Potential difference measurement: During the grouting process, while the current is injected into the excitation electrode, the potential difference at any point in the electrode array is measured. ; S4: Calculate the resistivity: The resistivity of any point in the electrode array: , where: Adjustment factors for test fixtures; is the potential difference between the measured electrodes; I is the supply current; S5: Geological body response judgment: The geological body response is judged by the difference in resistivity. When the geological body is dry, hollow or unfilled, it hinders the passage of current and appears as high resistance. When it is water-filled, hollow or water-rich, a path is formed to converge current, which appears as low resistance anomaly.

[0020] A method for preparing a conductive tracer material for detecting soil slurry flow during grouting to understand the diffusion range, flow distribution, and reinforcement effect of the reinforcement material in the soil, comprising the following steps: S1: Dry mixing: cement and fly ash are dry mixed; S2: Preparation of dispersion: After the graphite powder is mixed with the dispersant and water, tributyl phosphate is added to the dispersion and the mixture is thoroughly mixed by high-speed stirring to form a dispersion; S3: Tracer material: dry-mixed cement and fly ash are wet-mixed with the dispersion prepared above in a cement-sand mixer to obtain a tracer material; S4: Testing: The prepared tracer material is subjected to flowability test, water extraction rate test, and viscosity test.

[0021] The fluidity test of the conductive tracer material is carried out using an extended cone flow test plate and a rheometer. The grouting material is poured into the fluid mold and the material flows out naturally, and its diffusion diameter is measured to evaluate the material fluidity.

[0022] The water leaching rate test of the conductive tracer material is carried out using a glass plate and a standard container; the water leaching rate is calculated by comparing the height difference between the initial and final states of the conductive tracer material after it has been allowed to stand.

[0023] Conductive tracer material viscosity testing mainly uses a Marshall funnel and a standard cup test to evaluate the viscosity based on the time it takes for the material to flow into the standard cup.

[0024] The resistivity of the conductive tracer material was dynamically monitored during the curing period, and the time-varying dynamic monitoring results of the resistivity were fitted. It was found that the relationship between the resistivity and the curing age satisfies the following functional relationship: ; Where, ρ is the test resistivity of the grouting slurry, unit: Ω·cm, t For the maintenance age, t 0. ρ 1 、 ρ 2 are fitting parameters, among which ρ 1 、 ρ 2 They can indirectly reflect the initial monitoring stage and final state impedance of the material. t 0 reflects the time point when the resistivity of the tracer material increases fastest, p is the control parameter related to the time-varying properties of the material.

[0025] A conductive tracer material flexural strength test device is suitable for the above-mentioned conductive tracer material preparation method and is used for testing the mechanical properties of the tracer material. It includes an upper loading plate and a lower loading plate. Pressure is applied to the upper loading plate by a hydraulic rod. A spirit level is provided above the upper loading plate to ensure that it remains horizontal when pressure is applied. The upper loading plate is connected to an upper fixture back plate via a force transmission rod below. A lower fixture back plate is provided above the lower loading plate. A flexural test loading rod is accommodated between the upper and lower fixture back plates to contact a slurry sample.

[0026] In the geological body response of step S5, the moisture content of the soil, the relative resistivity of the soil, and the imaging field average all satisfy the following functional relationship: ; In the formula R is the test relative resistance of the soil, is the sensitive field characteristic value, a 0 、 b 0 、 c 0 are fitting parameters, ω is the soil moisture content.

[0027] A soil reinforcement visualization tracing simulation device, suitable for the aforementioned soil reinforcement visualization tracing method, comprises a spring electrode group surrounding a specimen. The spring electrode group is arranged in multiple layers longitudinally to acquire cross-sectional resistivity at different heights of the specimen, forming a three-dimensional measurement network. The spring electrode group is connected to an acquisition control unit for collecting the excitation and response voltages of the multiple layers of electrodes. The acquisition control unit is connected to a data processing unit, which fuses the resistivity data from multiple layers using an interpolation algorithm to reconstruct a complete three-dimensional resistivity distribution image within the specimen. Each layer of the spring electrode group (1) includes 16 spring electrodes (2) spaced evenly around the specimen, and the spring electrode group is arranged in six layers longitudinally.

[0028] To further investigate the traceability of graphite fly ash grouting materials during high-pressure jet grouting reinforcement of deep foundation pits, this study designed an indoor test platform. This platform used a 30-cm cube of acrylic as the experimental container and strip electrodes as measuring electrodes. The platform was filled with 80-mesh homogeneous glass sand to simulate the electrical properties of homogeneous sand at a scaled scale. Imaging tests were performed using a 16-electrode imaging system.

[0029] In practical grouting reinforcement projects, the scale of the excavation is a crucial factor influencing the grouting effect. As the excavation depth increases, the distribution and permeability of the grouting material may change. In particular, the electrical properties of the soil in deep excavations may be affected by more complex factors. To accurately evaluate the effectiveness of electrical resistance tomography (ERT) in deep excavation reinforcement, it is necessary to simulate the electrical properties and imaging results at different excavation scales.

[0030] There is a strong linear correlation between the excavation depth and the imaging field characteristic value, which shows that the existing acquisition conditions of the current indoor test platform can effectively reflect the changes in the voltage field value caused by the excavation depth. At the same time, as the excavation depth approaches the plane where the electrode is located, the test accuracy for the hole scale is higher. This shows that during the excitation process of the strip electrode, the collected field value mainly depends on the plane where the electrode is located, and the voltage field reflects the conductivity distribution of the test field. This experiment proves that the test site can realize imaging testing, and also proves that the distance between the electrode plane and the excavation depth can be further predicted by the imaging field average value, which has certain guiding significance for engineering to determine the three-dimensional spatial distance between the electrode and the hole and drill hole adjustment.

[0031] Similarly, correlation studies were conducted around different excavation widths. A strong linear correlation was also found between the excavation scale and the imaging field characteristic values. This also verified that the existing acquisition conditions of the current indoor test platform can effectively reflect the changes in voltage field values ​​caused by the excavation width. As the excavation width increases, when the excavation diameter is 2.5 and 5 cm, the sensitive field voltage changes caused by the excavation cannot be imaged through differential imaging. However, when the excavation diameter is about 7.5 cm, imaging of position and geometric dimensions can be achieved, and the imaging can reflect the changes caused by the excavation width. This shows that during the excitation process of the strip electrode, when the electrode position is fixed and the excavation depth is close to the electrode plane, the collected field value can reflect the impact of the excavation width. From the imaging perspective, the test accuracy of the equipment at the current indoor scale can meet the imaging requirements of a 7.5 cm diameter.

[0032] In summary, the excavation scale test determined the basic grouting imaging scale for subsequent grouting tests, namely, the excavation diameter and grouting range of the test site. While verifying that the test site can realize imaging testing, it also proved that the distance between the electrode plane and the excavation depth can be further predicted by the imaging field average value. This has certain guiding significance for determining the three-dimensional spatial distance between the electrode and the hole, adjusting the drilling hole, and adjusting the spatial distance between the electrode and the hole scale range.

[0033] Indoor tracer material grouting simulation Through the indoor test platform built above, through the indoor tomography grouting reinforcement simulation test, it was verified that the tracer material has significant advantages over ordinary cement-based grouting materials. The tracer slurry has tracer stability and can realize the full cycle monitoring of the grouting reinforcement process. After the slurry solidifies, compared with ordinary slurry, its electrical properties advantages enable it to still meet the imaging requirements, providing an economical, environmentally friendly, safe and stable tracer material option for determining the grouting reinforcement range and evaluating the grouting effect in grouting reinforcement projects. Finally, the significant advantages of tracer materials compared to ordinary materials are given, as shown in the following table:

[0034] Although some preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0035] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications of the present invention fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A soil reinforcement visual tracing method, characterized in that: The following steps are involved: S1: Excitation electrode array layout: Electrode arrays are laid out on the surface and in underground boreholes within the soil mass encompassing the survey area; S2: Excitation electrode discharge measurement: Using the prepared conductive tracer material, during the grouting process, direct current or low-frequency alternating current with a current of I is injected into the ground through the excitation electrode to form an artificial electric field in the underground medium; S3: Potential difference measurement: During the grouting process, while the current is injected into the excitation electrode, the potential difference at any point in the electrode array is measured. ; S4: Calculate the resistivity: The resistivity of any point in the electrode array: , where: Adjustment factors for test fixtures; is the potential difference between the measured electrodes; I is the supply current; S5: Geological body response judgment: The geological body response is judged by the difference in resistivity. When the geological body is dry, hollow or unfilled, it hinders the passage of current and appears as high resistance. When it is water-filled, hollow or water-rich, a path is formed to converge current, which appears as low resistance anomaly.

2. The soil reinforcement visualization tracing method according to claim 1, characterized in that: In the geological body response of step S5, the moisture content of the soil, the relative resistivity of the soil, and the imaging field average all satisfy the following functional relationship: ； In the formula R is the test relative resistance of the soil, is the sensitive field characteristic value, a 0 、 b 0 、 c 0 are fitting parameters, ω is the soil moisture content.

3. A soil reinforcement visualization tracing simulation device, suitable for the soil reinforcement visualization tracing method according to claim 1 or 2, characterized in that: The system includes a spring electrode group surrounding the sample. The spring electrode group is arranged in a multi-layer structure along the longitudinal direction to obtain the cross-sectional resistivity at different heights of the sample to form a three-dimensional measurement network. The spring electrode group is connected to an acquisition control unit for collecting the excitation and response voltages of the multi-layer electrodes. The acquisition control unit is connected to a data processing unit, which fuses the multi-layer resistivity data based on an interpolation algorithm to reconstruct a complete three-dimensional resistivity distribution image inside the sample.

4. A method for preparing a conductive tracer material, suitable for the soil reinforcement visualization tracer method according to claim 1, for detecting soil slurry flow during grouting to understand the diffusion range, flow distribution and reinforcement effect of the reinforcement material in the soil, characterized in that: The steps include: S1: Dry mixing: cement and fly ash are dry mixed; S2: Preparation of dispersion: After the graphite powder is mixed with the dispersant and water, tributyl phosphate is added to the dispersion and the mixture is thoroughly mixed by high-speed stirring to form a dispersion; S3: Tracer material: dry-mixed cement and fly ash are wet-mixed with the dispersion prepared above in a cement-sand mixer to obtain a tracer material; S4: Testing: The prepared tracer material is subjected to flowability test, water extraction rate test, and viscosity test.

5. The method for preparing a conductive tracer material according to claim 4, wherein: The fluidity test of the conductive tracer material is carried out using an extended cone flow test plate and a rheometer. The grouting material is poured into the fluid mold and the material flows out naturally, and its diffusion diameter is measured to evaluate the material fluidity.

6. The method for preparing a conductive tracer material according to claim 4, wherein: The water leaching rate test of the conductive tracer material is carried out using a glass plate and a standard container; the water leaching rate is calculated by comparing the height difference between the initial and final states of the conductive tracer material after it has been allowed to stand.

7. The method for preparing a conductive tracer material according to claim 4, wherein: Conductive tracer material viscosity testing mainly uses a Marshall funnel and a standard cup test to evaluate the viscosity based on the time it takes for the material to flow into the standard cup.

8. The method for preparing a conductive tracer material according to claim 4, wherein: The resistivity of the conductive tracer material was dynamically monitored during the curing period, and the time-varying dynamic monitoring results of the resistivity were fitted. It was found that the relationship between the resistivity and the curing age satisfies the following functional relationship: ； Where, ρ is the test resistivity of the grouting slurry, unit: Ω·cm, t For the maintenance age, t 0. ρ 1 、 ρ 2 are fitting parameters, among which ρ 1 、 ρ 2 They can indirectly reflect the initial monitoring stage and final state impedance of the material. t 0 reflects the time point when the resistivity of the tracer material increases fastest, p is the control parameter related to the time-varying properties of the material.

9. A conductive tracer material flexural strength tester, suitable for use in the method for preparing the conductive tracer material according to any one of claims 4 to 8, and used for testing the mechanical properties of the tracer material, characterized in that: It includes an upper loading plate and a lower loading plate. Pressure is applied to the upper loading plate through a hydraulic rod. A spirit level is set above the upper loading plate to ensure that it remains horizontal when pressure is applied. The upper loading plate is connected to the upper fixture back plate through a force transmission rod. The lower fixture back plate is set above the lower loading plate. The flexural test loading rod is accommodated between the upper and lower fixture back plates to contact the slurry sample.

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