In-situ visualized repair method based on migration behavior model of high-pressure jetting agent

Abstract

This invention discloses an in-situ visual remediation method based on a high-pressure jet spraying agent migration behavior model. The method is characterized by the following steps: (1) establishing an agent migration behavior model for in-situ remediation of contaminated soil based on high-pressure jet spraying, and obtaining the formula for the diffusion radius of the remediation agent; (2) conducting scientific and precise remediation of contaminated soil based on the established agent migration behavior model; and (3) conducting in-situ visual remediation based on high-density resistivity imaging technology.

Description

Technical Field

[0001] This invention belongs to the field of environmental pollution control technology, specifically targeting soil pollution remediation. It proposes an in-situ, visualized, and precise remediation method that combines high-pressure jet grouting technology with a pesticide migration behavior model. The core of this method lies in optimizing the remediation process parameters of high-pressure jet grouting through a precise pesticide migration behavior model, while simultaneously utilizing visualization technology for real-time monitoring and control, thereby achieving efficient and precise remediation of soil pollution. Background Technology

[0002] With economic growth, soil pollution is characterized by diverse pollution types, complex causes, and distinct regional distribution patterns. Soil pollution not only threatens agricultural product safety and human health but also affects social stability and sustainable development. Therefore, effective prevention and remediation of soil pollution should be promoted. In the soil pollution remediation technology system, in-situ remediation technology is widely used due to its high efficiency and flexibility. In particular, high-pressure jet grouting in-situ remediation technology effectively improves remediation results and economic benefits by precisely controlling the injection point, depth, and volume of the reagent. However, in practical applications, this technology still faces the challenge of unstable remediation effects due to the difficulty in accurately predicting the reagent diffusion radius. The uncertainty of the reagent diffusion radius and the instability of remediation effects not only increase the risks and uncertainties of project implementation but may also lead to cost overruns and extended remediation cycles, hindering the wider adoption and in-depth application of this technology and significantly restricting the timeliness and effectiveness of environmental governance.

[0003] The uncertainty of the chemical diffusion radius has always been a key factor restricting the widespread application of high-pressure jet grouting in-situ remediation technology. The lack of accurate injection models leads to low chemical injection efficiency and makes it difficult to accurately predict and control the remediation range, which is a core challenge in high-pressure jet grouting remediation construction. Traditional methods rely on test piles and experience to determine the diffusion behavior of chemicals in the soil, but the complexity and variability of the soil environment make this method difficult to achieve precise control. Specifically, the physicochemical properties of the soil medium, such as pore structure, permeability, and chemical reactivity, as well as unforeseen factors such as underground obstacles, all significantly affect the migration behavior of chemicals. Therefore, relying solely on experience and test pile results to guide operations cannot accurately control the actual diffusion of chemicals, which not only makes the effect of high-pressure jet grouting in-situ remediation unstable but may also lead to ineffective resource consumption. Summary of the Invention

[0004] This invention constructs a high-precision model of the migration behavior of high-pressure jet grouting agents, deeply integrating agent hybrid dynamics, convection-diffusion mechanisms, complex soil characteristics, and equipment parameters. This enables accurate calculation of the agent diffusion radius and efficient, precise injection, successfully overcoming the core challenge of agent diffusion radius uncertainty in high-pressure jet grouting in-situ remediation technology. Simultaneously, the introduction of high-density electrical resistivity detection technology allows for real-time monitoring of soil resistivity changes and three-dimensional visualization reconstruction, achieving visualized monitoring of the remediation process and improving the spatial positioning accuracy and operational controllability of the construction. More importantly, this invention can identify underground obstacles and optimize construction sites, ensuring uniform agent coverage of the contaminated area, significantly improving remediation efficiency and effectiveness, and enabling high-pressure jet grouting remediation to move from "blind" construction to data-driven "intelligent" remediation. The technical solution of this invention is as follows:

[0005] An in-situ visualization remediation method based on a high-pressure rotary spraying agent migration behavior model, comprising the following steps:

[0006] (1) A model of the migration behavior of remediation agents based on high-pressure jet grouting for in-situ remediation of contaminated soil was established, and the formula for the diffusion radius of the remediation agent was obtained as follows:

[0007]

[0008] In the formula, h is the diffusion radius (m); K is the permeability coefficient (m / d); n is the number of nozzles on the piling machine; d is the diameter of the nozzles on the piling machine (m); v is the velocity of the liquid agent when it exits the nozzle (m / s); ρsoil is the soil density of the stratum where the piling machine is operating; and ρliquid is the density of the remediation liquid agent (kg / m2). 3 σ is the soil compressive strength of the stratum where the pile driver is located during construction, in kPa;

[0009] (2) Based on the established model of agent migration behavior, scientific and precise remediation of contaminated soil is carried out;

[0010] (3) In-situ visual restoration based on high-density resistivity imaging technology

[0011] 1) A multi-electrode array configuration is adopted, and the electrode spacing is set according to the calculation results of the agent migration behavior model during the high-pressure jet in-situ remediation process to match the diffusion radius, until the electrodes cover the entire contaminated area.

[0012] 4) Based on the relationship between the change in electrical conductivity of contaminated soil and the concentration C of the reagent after soil injection, construct a subsurface resistivity distribution image to identify areas of resistivity anomaly.

[0013] 5) For areas with abnormal resistivity, the drilling layout of high-pressure jet grouting should be adjusted and optimized based on the historical use of the land plot.

[0014] Furthermore, the method of step (2) is as follows: calculate the diffusion radius of the agent, set the construction process according to the type and concentration of pollutants, determine the agent concentration and the number of injections, and carry out scientific and precise remediation of the contaminated soil.

[0015] Furthermore, in step (3), a multi-electrode array configuration is adopted. The electrode spacing is set according to the calculation results of the agent migration behavior model during high-pressure jet spraying in-situ remediation to match the diffusion radius, until the electrodes cover the entire contaminated area. The specific arrangement is as follows:

[0016] Central power supply electrode: Deployed around the pollution source to send current underground;

[0017] The first ring of measuring electrodes: arranged around the central power supply electrode, used to measure the change in electric field generated by the central power supply electrode;

[0018] The second ring of power supply electrodes: located outside the first ring of measuring electrodes, is used to send current into the ground to further detect the underground resistivity distribution;

[0019] Second ring of measuring electrodes: arranged around the second ring of power supply electrodes, used to measure the change in electric field generated by the second ring of power supply electrodes;

[0020] This process continues until the electrodes cover the entire contaminated area.

[0021] This invention proposes a precise soil remediation method combining a high-pressure jet grouting agent migration behavior model with in-situ visualization technology. By deeply studying the hybrid dynamics and convection-diffusion mechanisms of the agent during the high-pressure jet grouting process, and considering soil characteristics and equipment parameters, a high-precision agent migration model is constructed. This model can accurately calculate the agent diffusion radius, ensuring efficient and precise agent injection. High-density electrical resistivity tomography (EDT) is used to monitor soil resistivity changes in real time. Through data acquisition and 3D reconstruction, the remediation process is visualized and monitored, improving the spatial positioning accuracy and operational controllability of the construction. Simultaneously, by analyzing soil resistivity changes, anomalies are identified. Based on this information, the agent diffusion radius calculated using the high-pressure jet grouting agent migration behavior model is used to optimize the construction points, avoiding or adjusting injection points around obstacles to ensure uniform agent coverage of the contaminated area, thereby improving remediation efficiency and effectiveness. Attached Figure Description

[0022] Figure 1 (a) is a conceptual diagram of high-pressure jet grouting construction; (b) is the agent diffusion radius h calculated by the agent migration behavior model of in-situ remediation of contaminated site soil using high-pressure jet grouting.

[0023] Figure 2 This is a diagram showing the layout of high-pressure jet grouting points for contaminated soil.

[0024] Figure 3 This is a diagram showing the electrode arrangement points for a high-density electrical resistivity tomography (EDT) of soil.

[0025] Figure 4 Soil resistivity diagram of the contaminated site before chemical injection.

[0026] Figure 5 Soil resistivity diagram after chemical injection in contaminated site.

[0027] Figure 6 Interpretation diagram of soil resistivity before chemical injection in contaminated site.

[0028] Figure 7 Interpretation diagram of soil resistivity after chemical injection in contaminated site. Detailed Implementation

[0029] To further understand the content, features, and effects of this invention, and to explain the specific embodiments of this invention, the basic technical solution of this invention will be described below:

[0030] Definition: Site layout refers to the placement of in-situ injection points for chemicals on the ground within the contaminated area requiring remediation, based on three parameters: the pollution level, geological conditions, and the diffusion radius of the chemicals used in the remediation operation.

[0031] The in-situ visualization and precise remediation technology based on a high-pressure rotary spraying agent migration behavior model employed in this invention comprises the following steps:

[0032] (1) A model of reagent migration behavior in in-situ remediation of contaminated soil based on high-pressure jet grouting

[0033] In the process of high-pressure jet grouting for in-situ remediation of contaminated soil, the migration behavior of remediation agents mainly occurs through two modes: jet mixing and convective diffusion. By establishing a model of the migration behavior of high-pressure jet grouting agents under jet mixing and convective diffusion, the injection radius of the remediation agent during high-pressure jet grouting in-situ remediation can be accurately calculated. Based on the contamination status and geological structure data of the contaminated site, the optimal jet grouting parameters can be calculated to optimize the agent dosage, thereby reducing ineffective input and environmental pollution, and achieving precise agent injection. The agent migration behavior model for high-pressure jet grouting in-situ remediation of contaminated soil is shown below:

[0034]

[0035] In the formula, h is the diffusion radius (m); K is the permeability coefficient (m / d); n is the number of nozzles on the piling machine; d is the diameter of the nozzles on the piling machine (m); v is the velocity of the liquid agent when it exits the nozzle (m / s); ρsoil is the soil density of the stratum where the piling machine is operating; and ρliquid is the density of the remediation liquid agent (kg / m2). 3 σ is the soil compressive strength of the stratum where the pile driver is located during construction, in kPa.

[0036] (2) In-situ visualization monitoring system based on high-pressure jet spraying agent migration behavior model

[0037] In in-situ soil remediation, ensuring sufficient and efficient contact between the remediation agent and the contaminated soil is a core factor determining the remediation effect. This invention, based on a model of the migration behavior of high-pressure jet grouting agents in contaminated sites, employs high-density electrical resistivity tomography (HDE), a non-invasive geophysical detection technique, to achieve precise monitoring of the high-pressure jet grouting remediation process. By measuring minute changes in the current conduction characteristics of the soil, it indirectly reflects the spatial distribution of soil resistivity, thereby revealing the dynamic changes in the soil's electrical characteristics after agent injection. Combined with data processing algorithms, key information such as the range of agent migration behavior, concentration distribution, and migration dynamics are calculated from these electrical data, enabling visualization and quantitative assessment of the remediation process. This method not only improves the efficiency and accuracy of in-situ remediation but also promotes the transformation of soil remediation from traditional "blind" construction to data-driven "smart" remediation.

[0038] The injection of remediation agents will cause changes in soil resistivity. Measuring the soil resistivity in the construction area allows for real-time tracking of the agent's migration behavior in the soil. Furthermore, the concentration distribution of the injected agent in the soil can be calculated by analyzing the changes in soil resistivity. Combined with the soil pollution situation, the remediation effect can be predicted, providing more precise guidance for on-site remediation operations.

[0039] The change in electrical conductivity of contaminated soil is directly proportional to the concentration C of the agent injected into the soil, as calculated by the following formula:

[0040] Δρ=ρ2-ρ1

[0041] In the formula, ρ1 is the soil electrical conductivity before the injection of the agent, Ω·m; ρ2 is the soil electrical conductivity after the injection of the agent, Ω·m; Δρ is the change in the electrical conductivity of the polluted soil, Ω·m.

[0042] Formulas for changes in pesticide concentration and soil electrical conductivity after pesticide injection:

[0043] Δρ=k·C

[0044] C represents the pesticide concentration (%); k is the proportionality coefficient, reflecting the degree of influence of pesticide concentration on soil electrical conductivity changes. Since each plot is different, the proportionality coefficient k must be experimentally measured in the contaminated plot. It is determined by fitting data to a series of soil electrical conductivity changes under different pesticide concentrations.

[0045] Soil resistivity measurements were performed using a multi-electrode arrangement, with the electrode spacing determined by the diffusion radius h calculated from the high-pressure jet remediation agent migration behavior model. The specific arrangement was as follows:

[0046] Central power supply electrode: Deployed around the pollution source, used to send current underground.

[0047] The first ring of measuring electrodes: arranged around the central power supply electrode, used to measure the change in electric field generated by the central power supply electrode.

[0048] The second ring of power supply electrodes: located outside the first ring of measuring electrodes, sends current again to further probe the underground resistivity distribution.

[0049] Second ring of measuring electrodes: Arranged around the second ring of power supply electrodes, used to measure the electric field changes generated by the second ring of power supply electrodes.

[0050] This process continues until the electrodes cover the entire contaminated area.

[0051] The advantage of this method is that:

[0052] Improved resolution: By arranging multiple electrodes, the underground resistivity distribution can be studied in more detail, thus improving the resolution of exploration.

[0053] Enhanced signal strength: Multi-ring electrodes can generate stronger electric field signals, making it easier to detect changes in underground resistivity.

[0054] Reduce interference: By arranging multiple electrodes, external interference signals can be better suppressed, improving the accuracy of measurement results.

[0055] This invention utilizes high-precision acquisition of contaminated soil resistivity data, combined with inversion algorithms and imaging technology, to construct high-resolution images of underground resistivity distribution. These images not only visually demonstrate the dynamic migration process and concentration gradient of remediation agents in the soil but also accurately depict underground geological structural features, including potential obstacles and geological anomalies. For example, by combining historical land use information, underground obstacles such as rock layers, old structures, and underground pipelines can be identified. This provides a scientific basis for the precise layout of high-pressure jet grouting injection points, ensuring the effectiveness and economy of remediation work while minimizing unnecessary construction interventions and resource waste.

[0056] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the technical solutions of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] Step 1: Based on the pesticide migration behavior model for in-situ remediation of contaminated soil using high-pressure jet grouting, for the calculation of the pesticide diffusion radius (h), please refer to [link to relevant documentation]. Figure 1 , Figure 2 The specific details are as follows:

[0058] High-pressure jet grouting in-situ remediation technology involves inserting a grouting pipe (drill rod) with a special nozzle into the soil at a predetermined depth through a borehole. Then, a pre-prepared remediation agent is sprayed from the nozzle while the grouting pipe rotates upwards during the spraying process. The high-pressure liquid agent cuts and mixes with the soil, ensuring thorough mixing of the remediation agent with the contaminated soil. Through a chemical reaction, the contaminants are decomposed into low-toxicity or non-toxic products, thereby achieving the purpose of remediating the contaminated soil. Figure 1 ).

[0059] Based on the hydrogeological report, site pollution investigation report, and high-pressure jet grouting equipment parameters of the contaminated site, seven parameters were selected: permeability coefficient, soil compressive strength, soil density, remediation agent density, agent injection velocity, number of nozzles on the grouting machine, and nozzle diameter. These parameters were then substituted into a model of agent migration behavior for in-situ remediation of contaminated soil using high-pressure jet grouting to calculate the diffusion radius of the high-pressure jet grouting agent. The layout of the high-pressure jet grouting boreholes was then determined according to the calculated diffusion radius. Figure 2 ).

[0060]

[0061] Table 1. Parameters related to the model in the embodiment:

[0062] Research parameters symbol unit Value Drug diffusion radius h m Permeability coefficient K m / d 1 Number of nozzles n indivual 2 Nozzle diameter d m 0.002 jet speed v m / s 200 Soil density ρ_soil <![CDATA[kg / m 3 ]]> 1.85 Repair agent density ρ liquid <![CDATA[kg / m 3 ]]> 1.35 Soil compressive strength σ kPa 0.2

[0063] Based on the formula for calculating the diffusion radius of high-pressure jet spraying agent, and taking the relevant parameters of the plot in the example from the values ​​in the table above, the diffusion radius of high-pressure jet spraying agent in the example plot is calculated to be 1.5m.

[0064] Step 2: In-situ visualization monitoring system based on high-pressure rotary spraying agent migration behavior model. (Please refer to...) Figure 3-7 The specific details are as follows:

[0065] Based on the conceptual model of the contaminated site, and taking the pollution source as the center, the electrode spacing was determined according to the agent diffusion radius (1.5m) calculated by the high-pressure jet grouting in-situ remediation soil agent migration behavior model. A multi-electrode arrangement was used, with electrodes evenly distributed in all directions of the pollution plume. The resistivity of the contaminated site was measured using a three-dimensional high-density electrical resistivity method, and resistivity imaging tests were conducted based on the spatial distribution of soil resistivity. Figure 4 Based on resistivity imaging, the drilling layout of high-pressure jet grouting can be adjusted and optimized for areas with resistivity anomalies, taking into account the historical use of the land parcel (such as buildings and structures).

[0066] Based on the in-situ injected agent migration behavior model, the agent diffusion radius is scientifically calculated. According to the pollutant type and concentration, the construction process (determining the agent concentration and number of injections) is set to carry out scientific and precise remediation of contaminated soil.

[0067] After the injection, the soil resistivity of the injection area was measured again, based on soil resistivity imaging test (…). Figure 5 This study analyzes the diffusion of the pesticide in the soil to achieve visualized monitoring of the high-pressure jet grouting process. The injection of the pesticide causes significant changes in soil resistivity (see...). Figure 4 , Figure 5 Before the injection, the average soil resistivity was 2.84 Ω·m, and after the injection, it was 2.42 Ω·m. The injection of the pesticide led to a decrease in the soil resistivity. Based on equations (2) and (3), the k value for this example plot is 1.51. According to the change in soil resistivity of 0.42 Ω·m, the average mass concentration of the pesticide in the soil can be calculated to be 27.81%.

[0068] Δρ=ρ2-ρ1(2)

[0069] Δρ=k·C(3)

[0070] Interpretive analysis of soil resistivity before and after pesticide injection revealed three anomalous areas in the underground soil of the example plot before injection. Figure 6 The red area, based on the site's historical use (factory buildings), is preliminarily identified as a legacy foundation. During high-pressure jet grouting, the number of injection points in this area can be appropriately increased to improve repair efficiency. After injection, the overall chemical diffusion effect on this example site was good (see...). Figure 7 However, there were still two areas where the drug injection effect was not ideal. Figure 7 The yellow area can be treated with additional medication to improve the quality of the repair.

[0071] In summary, this invention establishes a model of the agent migration behavior for in-situ remediation of contaminated soil using high-pressure jet grouting. This model accurately calculates the diffusion radius of the agent in the soil during high-pressure jet grouting and uses this information to determine the location of high-pressure jet grouting sites. During construction, real-time monitoring of the contaminated soil resistivity transforms the previously invisible underground construction process into a visual model. This allows for monitoring of both the agent's diffusion range and concentration to ensure that the actual injection of the agent achieves the predetermined goals according to the set process parameters. This enables precise application of agents under different contamination concentrations, pollutants, and geological conditions, addressing the problems of over-application and over-remediation in existing technologies. From a technical perspective, this achieves scientific, green, and sustainable remediation.

Claims

1. An in-situ visual remediation method based on a high-pressure rotary spraying agent migration behavior model, characterized in that... The steps are as follows: (1) A model of the migration behavior of remediation agents based on high-pressure jet grouting for in-situ remediation of contaminated soil was established, and the formula for the diffusion radius of the remediation agent was obtained as follows: In the formula, h is the diffusion radius (m); K is the permeability coefficient (m / d); n is the number of nozzles on the piling machine; d is the diameter of the nozzle on the piling machine (m); v is the velocity of the liquid agent when it exits the nozzle (m / s); ρ 土 ρ is the soil density of the stratum where the piling machine is installed. 液 To restore the density of the liquid agent, kg / m³ 3 σ is the soil compressive strength of the stratum where the pile driver is located during construction, in kPa; (2) Based on the established model of agent migration behavior, scientific and precise remediation of contaminated soil is carried out; (3) In-situ visual restoration based on high-density resistivity imaging technology 1) A multi-electrode array configuration is adopted, and the electrode spacing is set according to the calculation results of the agent migration behavior model during high-pressure jet grouting in-situ remediation to match the diffusion radius, until the electrodes cover the entire contaminated area. The specific arrangement of the multi-electrode array configuration, which sets the electrode spacing according to the calculation results of the agent migration behavior model during high-pressure jet grouting in-situ remediation to match the diffusion radius, until the electrodes cover the entire contaminated area, is as follows: Central power supply electrode: Deployed around the pollution source to send current underground; The first ring of measuring electrodes: arranged around the central power supply electrode, used to measure the change in electric field generated by the central power supply electrode; The second ring of power supply electrodes: located outside the first ring of measuring electrodes, is used to send current into the ground to further detect the underground resistivity distribution; Second ring of measuring electrodes: arranged around the second ring of power supply electrodes, used to measure the change in electric field generated by the second ring of power supply electrodes; This process continues until the electrodes cover the entire contaminated area; 2) Based on the relationship between the change in electrical conductivity of contaminated soil and the concentration C of the agent after soil injection, a subsurface resistivity distribution image is constructed to identify areas of resistivity anomaly. 3) For areas with abnormal resistivity, the drilling layout of high-pressure jet grouting should be adjusted and optimized based on the historical use of the land plot.

2. The in-situ visual remediation method based on the high-pressure rotary spraying agent migration behavior model according to claim 1, characterized in that, The method for step (2) is as follows: calculate the diffusion radius of the agent, set the construction process according to the type and concentration of pollutants, determine the agent concentration and number of injections, and carry out scientific and precise remediation of the contaminated soil.

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