A discrete element analysis method for determining the anti-blocking efficiency of electro-osmosis drainage plate

Abstract

This invention provides a discrete element analysis method for determining the electroosmotic anti-clogging efficiency of drainage boards. The method includes: collecting soil survey data and calculating soil sample parameters; establishing a three-dimensional soil model using PFC particle flow software based on the soil survey data and the parameters of fine clay particles; initiating electroosmotic analysis by applying voltage to the positive and negative electrodes, causing the negatively charged fine clay particles in the soil to undergo electrophoresis under the influence of the electric field; determining the migration and distribution of fine clay particles around the drainage board under the electroosmotic effect during the energizing time through particle flow numerical simulation analysis; shutting down the electroosmotic analysis and simulating the drainage situation of vacuum preloading and consolidation in the upper part of the soil layer; studying the changes in particle content distribution in the soil layer and analyzing the possibility of the drainage board being blocked by fine clay particles after electroosmosis. This invention provides a fast and convenient method for simulating the construction of electroosmotic drainage boards in soil layers and predicting the anti-clogging efficiency of drainage boards using PFC.

Description

Technical Field

[0001] This invention belongs to the field of PFC numerical simulation analysis, specifically involving a discrete element analysis method for determining the electroosmotic anti-clogging efficiency of drainage boards. Background Technology

[0002] PFC (Particle Flow Follow Code), as a discrete element numerical simulation analysis software, can well reflect the flow phenomenon of granular materials at the microscopic level, and can effectively simulate the migration of fine clay particles under electroosmosis.

[0003] The search revealed that application CN202210131195.8, entitled "A Device and Method for Electro-osmosis Prevention of Drainage Boards," inserts two positive electrodes into the soil on both sides of a drainage board. By arranging DC electrodes on the metal wire and the positive electrodes respectively, electro-osmosis is carried out, which migrates fine clay particles in the soil from the vicinity of the drainage board to the area around the positive electrodes. However, this electro-osmosis prevention device for drainage boards cannot determine the migration of fine clay particles under electro-osmosis in actual engineering projects, and it is impossible to determine whether the electro-osmosis prevention efficiency of the device achieves the expected target.

[0004] In summary, the existing technology has the following drawbacks: due to the large differences in the particle composition of the drainage soil layer, it is impossible to obtain the electro-osmotic anti-clogging efficiency of the drainage board without conducting experiments. Furthermore, it is impossible to pre-adjust the device settings and the voltage applied to the positive electrode for different soil layers, resulting in a low electro-osmotic anti-clogging efficiency of the drainage board after construction, which leads to the need for re-installation of the device and waste of manpower and resources. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, the present invention aims to provide a discrete element analysis method for determining the electro-osmotic anti-clogging efficiency of drainage boards, providing a fast and convenient method for PFC simulation of soil drainage construction and prediction of drainage board anti-clogging efficiency.

[0006] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0007] This invention provides a discrete element analysis method for determining the electroosmotic anti-clogging efficiency of drainage boards, the method comprising:

[0008] Step S1: Collect soil layer survey data, obtain the particle size distribution of soil samples using the sieve method, and calculate the percentage w of fine clay particles based on the obtained particle size distribution, soil density ρ, soil moisture content θ, soil porosity n and soil electrical conductivity σ of the soil samples.

[0009] Step S2: Numerical simulation analysis is performed using PFC particle flow software. A three-dimensional soil layer model is established based on soil exploration data and parameters of fine clay particles. In the three-dimensional soil layer model, two negative electrodes are set at both ends of the drainage board, and two positive electrodes with a width of d are symmetrically set in the soil layer at a distance D on both sides of the drainage board. The depth H of the lower end of the positive electrode is consistent with the depth of the drainage board.

[0010] Step S3: Begin electroosmotic analysis. Set a voltage V on the two positive electrodes and a voltage 0 on the two negative electrodes to induce electrophoresis of negatively charged fine clay particles in the soil under the influence of the electric field. Numerical simulation analysis of particle flow is used to determine the migration of fine clay particles and their distribution around the drainage board under electroosmotic action during the energizing time T1.

[0011] Step S4: Turn off the electroosmotic analysis, set up drainage nodes on the drainage board to simulate the drainage situation of vacuum preloading drainage consolidation method in the upper part of the soil layer, and set the vacuum pressure P and drainage time T2 on the drainage nodes.

[0012] Step S5: Investigate the migration and redistribution of fine clay particles around the drainage board, the changes in particle content distribution in the soil layer, and analyze the possibility of the drainage board being blocked by fine clay particles after electroosmosis.

[0013] Step S6: Change parameters such as electroosmotic energizing time T1, percentage of fine clay particles w, soil conductivity σ, energizing voltage V, distance D between positive electrode and drainage board, depth H of positive electrode insertion into soil layer, and width d of positive electrode. Through particle flow numerical simulation analysis, determine the migration of fine clay particles and their distribution around the drainage board under electroosmosis.

[0014] Beneficial effects

[0015] The technical solutions provided in the embodiments of the present invention have the following beneficial effects:

[0016] The discrete element analysis method for determining the electro-osmotic anti-clogging efficiency of drainage boards provided in this invention collects soil survey data, calculates soil sample parameters, and establishes a three-dimensional soil model using PFC particle flow software based on the soil survey data and clay particle parameters. By changing parameters such as the electro-osmotic energizing time T1, the percentage of clay particles w, the soil conductivity σ, the energizing voltage V, the distance D between the positive electrode and the drainage board, the insertion depth H of the positive electrode into the soil layer, and the width d of the positive electrode, different foundation models are obtained to determine the migration and distribution of clay particles around the drainage board under electro-osmosis. This allows for the acquisition of information on the migration and distribution of clay particles around the drainage board under electro-osmosis in actual engineering projects. This invention solves the problem that drainage board electro-osmotic anti-clogging devices cannot determine the migration of clay particles under electro-osmosis in actual engineering projects and cannot determine whether the device achieves its electro-osmotic anti-clogging efficiency. This invention provides a fast and convenient method for simulating soil drainage construction and predicting the anti-clogging efficiency of drainage boards using PFC.

[0017] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of the discrete element analysis method for determining the electroosmotic anti-clogging efficiency of drainage boards according to an embodiment of the present invention;

[0020] Figure 2 This is a top view of the PFC simulated drainage board electroosmosis model according to an embodiment of the present invention;

[0021] Figure 3 This is a front view of the PFC simulated drainage board electroosmosis model according to an embodiment of the present invention;

[0022] Figure 4 This is a particle distribution diagram at the end of drainage of the PFC simulated drainage board according to an embodiment of the present invention. Detailed Implementation

[0023] After discovering the aforementioned shortcomings of the prior art, the inventors of this application conducted a detailed study on the mechanical properties of fine clay particles. The study found that under electroosmosis, negatively charged fine clay particles exhibit electrophoresis, with most migrating towards the positive electrode. The number of fine clay particles around the negative electrode significantly decreases, the soil permeability coefficient significantly increases, and the electroosmotic anti-clogging efficiency of the drainage board significantly improves. Based on this, the distribution of fine clay particles in the model soil before and after drainage consolidation can be obtained through numerical simulation analysis. Before electroosmosis, the number of fine clay particles in the square region S is N. 初始 After drainage and consolidation, it becomes N. 结束 If N 结束 / N 初始 If the particle size is ≤0.2~0.4, then the migration effect of the fine particles generated by electroosmosis is considered to meet the requirements and to prevent the drainage board from clogging.

[0024] This application, taking into account the migration characteristics of fine clay particles towards the positive electrode under electroosmosis, uses PFC particle flow software to simulate the electrophoretic migration of fine clay particles in the soil layer. This allows for the acquisition of data on the migration of fine clay particles under electroosmosis and their distribution around drainage boards in practical engineering applications. Based on this, this application provides a discrete element analysis method for determining the electroosmotic anti-clogging efficiency of drainage boards.

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can also be combined with each other.

[0026] like Figure 1 The diagram shown is a flowchart of a discrete element analysis method for determining the electroosmotic anti-clogging efficiency of drainage boards according to an embodiment of the present invention. The method includes the following steps:

[0027] Step S1: Collect soil layer survey data, obtain the particle size distribution of soil samples using the sieve method, and calculate the percentage w of fine clay particles based on the obtained particle size distribution, soil density ρ, soil moisture content θ, soil porosity n and soil electrical conductivity σ of the soil samples.

[0028] Step S2: Numerical simulation analysis is performed using PFC particle flow software. A three-dimensional soil layer model is established based on soil exploration data and parameters of fine clay particles. In the three-dimensional soil layer model, two negative electrodes are set at both ends of the drainage board, and two positive electrodes with a width of d are symmetrically set in the soil layer at a distance D on both sides of the drainage board. The depth H of the lower end of the positive electrode is consistent with the depth of the drainage board.

[0029] Step S3: Begin electroosmotic analysis. Set a voltage V on the two positive electrodes and a voltage 0 on the two negative electrodes to induce electrophoresis of negatively charged fine clay particles in the soil under the influence of the electric field. Numerical simulation analysis of particle flow is used to determine the migration of fine clay particles and their distribution around the drainage board under electroosmotic action during the energizing time T1.

[0030] Step S4: Turn off the electroosmotic analysis, set up drainage nodes on the drainage board to simulate the drainage situation of vacuum preloading drainage consolidation method in the upper part of the soil layer, and set the vacuum pressure P and drainage time T2 on the drainage nodes.

[0031] Step S5: Investigate the migration and redistribution of fine clay particles around the drainage board, the changes in particle content distribution in the soil layer, and analyze the possibility of the drainage board being blocked by fine clay particles after electroosmosis.

[0032] Step S6: Change parameters such as electroosmotic energizing time T1, percentage of fine clay particles w, soil conductivity σ, energizing voltage V, distance D between positive electrode and drainage board, depth H of positive electrode insertion into soil layer, and width d of positive electrode. Through particle flow numerical simulation analysis, determine the migration of fine clay particles and their distribution around the drainage board under electroosmosis.

[0033] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

[0034] The invention will be further explained in detail below through a specific example. Figure 4 This is a particle distribution diagram at the end of drainage of the PFC simulated drainage board according to an embodiment of the present invention.

[0035] Step S1: Collect soil layer survey data, obtain the particle size distribution of the soil sample using the sieve analysis method, and calculate the percentage w of fine clay particles based on the obtained particle size distribution, soil density ρ, soil moisture content θ, soil porosity n, and soil electrical conductivity σ. The particle size distribution of the soil sample obtained by the sieve analysis method is as follows:

[0036] Table 1 Particle size distribution of soil samples

[0037] mass percentage / % 0.8 5.8 12 18 12.1 19.5 25 6.8

[0038] Step S2: Numerical simulation analysis was performed using PFC particle flow software. A three-dimensional soil model was established based on soil survey data and parameters of fine clay particles, and soil parameters were set. In the three-dimensional soil model, two negative electrodes were placed at each end of the drainage board. Two positive electrodes with a width of 1 meter were symmetrically placed in the soil layer at a distance D of 10 cm on both sides of the drainage board. The penetration depth H of the lower end of the positive electrodes was 5 meters, consistent with the depth of the drainage board. The initial values ​​of the soil parameters are shown in the table below:

[0039] Table 2 Initial values ​​of soil parameters

[0040]

[0041] Step S3: Begin electroosmotic analysis. Set a voltage V of 12.5 volts on the two positive electrodes and a voltage of 0 volts on the two negative electrodes to induce electrophoresis of negatively charged fine clay particles in the soil under the influence of the electric field. Determine the migration of fine clay particles and their distribution around the drainage board under electroosmotic conditions with an energizing time T1 of 3 hours through particle flow numerical simulation analysis.

[0042] Step S4: Turn off the electroosmotic analysis, set up drainage nodes on the drainage board, and simulate the drainage situation of the vacuum preloading drainage consolidation method in the upper part of the soil layer. Set the vacuum pressure P on the drainage node to maintain 80 kPa and the drainage time T2 to 24 hours.

[0043] Step S5: Investigate the migration and redistribution of fine clay particles around the drainage board, the changes in particle content distribution in the soil layer, and analyze the possibility of the drainage board being blocked by fine clay particles after electroosmosis.

[0044] Step S6: Change parameters such as electroosmotic energizing time T1, percentage of fine clay particles w, soil conductivity σ, energizing voltage V, distance D between positive electrode and drainage board, depth H of positive electrode insertion into soil layer, and width d of positive electrode. Through particle flow numerical simulation analysis, determine the migration of fine clay particles and their distribution around the drainage board under electroosmosis.

[0045] The discrete element analysis method for determining the electro-osmotic anti-clogging efficiency of drainage boards provided in this invention collects soil survey data, calculates soil sample parameters, and establishes a three-dimensional soil model using PFC particle flow software based on the soil survey data and clay particle parameters. By changing parameters such as the electro-osmotic energizing time T1, the percentage of clay particles w, the soil conductivity σ, the energizing voltage V, the distance D between the positive electrode and the drainage board, the insertion depth H of the positive electrode into the soil layer, and the width d of the positive electrode, different foundation models are obtained to determine the migration and distribution of clay particles around the drainage board under electro-osmosis. This allows for the acquisition of information on the migration and distribution of clay particles around the drainage board under electro-osmosis in actual engineering projects. This invention solves the problem that drainage board electro-osmotic anti-clogging devices cannot determine the migration of clay particles under electro-osmosis in actual engineering projects and cannot determine whether the device achieves its electro-osmotic anti-clogging efficiency. This invention provides a fast and convenient method for simulating soil drainage construction and predicting the anti-clogging efficiency of drainage boards using PFC.

[0046] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed, and is not intended to limit the scope of the claimed invention, but merely to illustrate preferred embodiments of the invention. Those skilled in the art should understand that the scope of the invention is not limited to the specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A discrete element analysis method for determining the electroosmotic anti-clogging efficiency of drainage boards, characterized in that, The method includes: Step S1: Collect soil layer survey data, obtain the particle size distribution of soil samples using the sieve method, and calculate the percentage w of fine clay particles based on the obtained particle size distribution, soil density ρ, soil moisture content θ, soil porosity n and soil electrical conductivity σ of the soil samples. Step S2: Numerical simulation analysis is performed using PFC particle flow software. A three-dimensional soil model is established using soil exploration data and parameters of fine clay particles. In the three-dimensional soil model, two negative electrodes are set at both ends of the drainage board, and two positive electrodes with a width of d are symmetrically set in the soil layer at a distance D on both sides of the drainage board. The depth H of the lower end of the positive electrode is consistent with the depth of the drainage board. Step S3: Start the electroosmotic analysis. Set a voltage V on the two positive electrodes and a voltage 0 on the two negative electrodes to allow the negatively charged clay particles in the soil layer to undergo electrophoresis under the action of the electric field. Determine the migration of clay particles and their distribution around the drainage board under the action of electroosmosis during the energizing time T1 through particle flow numerical simulation analysis. Step S4: Turn off the electroosmotic analysis, set up drainage nodes on the drainage board to simulate the drainage situation of the upper soil layer under vacuum preloading drainage consolidation method, and set the vacuum pressure P and drainage time T2 on the drainage nodes. Step S5: Study the migration and redistribution of fine clay particles around the drainage board, the changes in particle content distribution in the soil layer, and analyze the possibility of the drainage board being blocked by fine clay particles after electroosmosis. Step S6: Change the parameters of electroosmotic energizing time T1, clay fine particle content percentage w, soil electrical conductivity σ, energizing voltage V, distance D between positive electrode and drainage board, depth H of positive electrode insertion into soil layer and width d of positive electrode, and determine the migration of clay fine particles and their distribution around the drainage board under electroosmosis through particle flow numerical simulation analysis. The distribution of fine clay particles in the model soil before and after drainage consolidation was obtained through numerical simulation analysis. Before electroosmosis, the number of fine clay particles in the square region S was N. 初始 After drainage and consolidation, it becomes N. 结束 If N 结束 / N 初始 If the particle size is ≤0.2~0.4, then the migration effect of the fine particles generated by electroosmosis is considered to meet the requirements and to prevent the drainage board from clogging.

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