Residual soil conductivity coefficient correction method

Abstract

The application provides a residual soil conductivity coefficient correction method, the residual soil is assumed to be composed of fine-grained soil body and coarse-grained gravel mixture; the residual soil conductivity coefficient correction method comprises the following steps: constructing a parallel model of the residual soil, and calculating a conductivity coefficient σ F‑C(P) of the parallel model; constructing a series model of the residual soil, and calculating a conductivity coefficient σ F‑C(S) of the series model; constructing a series-parallel hybrid model of the residual soil, and calculating a conductivity coefficient σ F‑C(SP) of the series-parallel hybrid model; correcting the conductivity coefficient σ F‑C(SP) of the series-parallel hybrid model, and obtaining a corrected conductivity coefficient σ F‑CM(SP) of the residual soil. The corrected conductivity coefficient σ F‑CM(SP) of the application is in good agreement with the experimental measurement value, has certain precision, and solves the problems of inaccurate calculation and poor applicability of the existing residual soil conductivity coefficient.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, specifically to a method for correcting the conductivity coefficient of residual soil. Background Technology

[0002] Residual soil has advantages such as good compressive strength, high shear strength, strong bearing capacity and good permeability. It is widely used as a building material in road construction, dam construction and foundation construction.

[0003] The electrical conductivity of residual soil is closely related to its structural parameters. Therefore, solving the problem of residual soil conductivity requires research into its structure.

[0004] Due to limited information on the internal structure of residual soil, the current approach is to calculate its conductivity by identifying the interval spanned by its reasonable and effective properties. Specifically, if the residual soil medium is two-phase and only its volume fraction is known, the interval is provided by the classical Wiener conductivity boundary. The Wiener conductivity boundary provides a selection interval within which the effective conductivity of the heterogeneous solid should always exist. If more characteristics are known, the Wiener boundary can be narrowed down to the Hashin-Shtrikman boundary. The Hashin-Shtrikman conductivity boundary provides the narrowest isotropic boundary without defining the geometry between the two phases of the residual soil medium.

[0005] However, the method of calculating the conductivity of residual soil based on the range spanned by the reasonable and effective properties of residual soil often suffers from inaccurate calculations and poor applicability. Summary of the Invention

[0006] The purpose of this invention is to provide a method for correcting the conductivity of residual soil. By studying the composition of residual soil, which consists of freely arranged fine-grained soil and coarse-grained gravel, a corrected model is established for the theoretical calculation of the conductivity of residual soil. This corrected model considers the influence of variations in porosity, saturation, and the volume content of coarse-grained gravel on the conductivity of residual soil. The corrected model has been verified through laboratory tests and demonstrates high accuracy in calculating the conductivity of residual soil, solving the problems of inaccurate and poorly applicable calculations of the conductivity of residual soil in existing methods. The specific technical solution is as follows:

[0007] A method for correcting the electrical conductivity of residual soil, wherein the residual soil is assumed to be composed of a mixture of fine-grained soil and coarse-grained gravel; the method for correcting the electrical conductivity of residual soil includes:

[0008] Step S1: Construct a parallel model of the residual soil along the seepage direction and calculate the conductivity of the parallel model. s F-C(P) ;

[0009] A series model of the residual soil was constructed in the vertical seepage direction, and the conductivity of the series model was calculated. s F-C(S) ;

[0010] Step S2: Assuming the volume content of coarse gravel and the volume content of fine soil are the same in both the series and parallel models, construct a series-parallel hybrid model of residual soil and calculate the conductivity of the series-parallel hybrid model. s F-C(SP) ;

[0011] Step S3: Conductivity of the series-parallel hybrid model s F-C(SP) The conductivity of the residual soil was corrected to obtain the corrected conductivity coefficient. s F-CM(SP) .

[0012] Optionally, in step S1, all the fine-grained soil in the residual soil is combined into a soil layer, and all the coarse-grained gravel in the residual soil is combined into a gravel layer.

[0013] In the parallel model of residual soil, the soil layer and the gravel layer are arranged side by side along the seepage direction;

[0014] In the series model of residual soil, the soil layer and the gravel layer are arranged side by side perpendicular to the seepage direction.

[0015] Optionally, the conductivity of the parallel model s F-C(P) Expressed using equation (1):

[0016] (1);

[0017] The conductivity of the series model s F-C(S) Expressed using equation (2):

[0018] s F-C(S) = C F s F + C C s C (2);

[0019] In equations (1)-(2), s F Indicates the electrical conductivity of fine-grained soil; s C This represents the electrical conductivity of coarse-grained crushed stone. CF This indicates the volume fraction of fine-grained soil in residual soil. C C This indicates the volume fraction of coarse gravel in residual soil.

[0020] Optionally, in step S2, the series-parallel hybrid model is a model combining the series model and the parallel model;

[0021] The conductivity of the series-parallel hybrid model s F-C(SP) Expressed using equation (3):

[0022] (3);

[0023] in, α The structural factor of the residual soil represents the structural proportion of the series model in the series-parallel hybrid model.

[0024] Optionally, in step S3, the Keller–Frischknecht model is used to evaluate the conductivity of the series-parallel hybrid model. s F-C(SP) The conductivity in the Keller–Frischknecht model is corrected. s Expressed using equation (4):

[0025] (4);

[0026] Conductivity in a series-parallel hybrid model s F-C(SP) ,Will s F-C(SP) Substituting into equation (4), we obtain equation (5):

[0027] (5);

[0028] The modified model is obtained by mixing all soil and gravel layers in the series-parallel hybrid model, and the conductivity of the modified model is measured. s F-CM(SP) ,Will s F-CM(SP) Substituting into equation (4), we obtain equation (6):

[0029] (6);

[0030] Comparing equation (6) with equation (5), we obtain equation (7):

[0031] (7);

[0032] The electrical conductivity of the modified residual soil is obtained using equation (7). s F-CM(SP) ;

[0033] In equations (4)-(7), n This represents porosity in the Keller–Frischknecht model; m This represents the cementation coefficient in the Keller–Frischknecht model; p This represents the saturation parameter in the Keller–Frischknecht model; S r This represents the saturation level in the Keller–Frischknecht model; a This represents specific parameters of fine-grained soil in the Keller–Frischknecht model; r w This represents the pore water resistivity in the Keller–Frischknecht model; n F-C This represents porosity in a series-parallel hybrid model; n F-CM This indicates the porosity in the modified model; n F-CM These are measured values; S r(F-C) This indicates the degree of saturation in a series-parallel hybrid model. S r(F-CM) This indicates the degree of saturation in the correction model.

[0034] Optionally, porosity in the series-parallel hybrid model n F-C Expressed using equation (8):

[0035] n F-C = n F C F + n C C C (8);

[0036] In equation (8), n F Indicates the porosity of fine-grained soils; n C Indicates the porosity of coarse-grained crushed stone; n F and n C All values ​​were measured under the same compaction conditions.

[0037] Optional, Sr(F-C) Expressed using equation (9):

[0038] (9);

[0039] In equation (9), S r(F) Indicates the degree of saturation of fine-grained soil; S r(C) This indicates the saturation level of coarse-grained crushed stone.

[0040] Optional, S r(F) Expressed using equation (10):

[0041] (10);

[0042] In equation (10), V w(F) This represents the volume of water in the pores of fine-grained soil. V v(F) This represents the total pore volume of fine-grained soil. oh 1 indicates the water content of fine-grained soil; G F This indicates the proportion of fine-grained soil in the series-parallel hybrid model.

[0043] Optional, S r(C) Expressed using equation (11):

[0044] (11);

[0045] In equation (11), V w(C) This represents the volume of water in the pores of coarse-grained gravel; V v(C) This represents the total pore volume of coarse-grained crushed stone; oh 2 indicates the moisture content of coarse-grained crushed stone; G C This indicates the proportion of coarse-grained crushed stone in the series-parallel hybrid model.

[0046] Optional, S r(F-CM) Expressed using equation (12):

[0047] (12);

[0048] In equation (12), V w(F-CM) This represents the volume of water in the pores of the residual soil in the corrected model; V v(F-CM) This represents the total pore volume of the residual soil in the modified model; oh3 indicates the moisture content of the residual soil in the corrected model; G F-CM This indicates the proportion of residual soil in the modified model;

[0049] In equations (10)-(12), oh 1. oh 2. oh 3. The values ​​are the same;

[0050] G F-CM Expressed using equation (13):

[0051] G F-CM = G F C F + G C C C (13).

[0052] The application of the technical solution of the present invention has at least the following beneficial effects:

[0053] The method for correcting the conductivity of residual soil described in this invention first establishes parallel and series models of the residual soil, then combines the two into a hybrid series-parallel model, and finally corrects the conductivity to obtain the corrected conductivity. s F-CM(SP) It matches the experimental measurements well and has a certain degree of accuracy, solving the problems of inaccurate calculation and poor applicability of the conductivity coefficient of existing residual soil.

[0054] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0055] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0056] Figure 1 This is a flowchart illustrating a method for correcting the conductivity of residual soil according to Embodiment 1 of the present invention.

[0057] Figure 2 This is a structural diagram of the parallel model in Embodiment 1 of the present invention;

[0058] Figure 3 This is a structural diagram of the series model in Embodiment 1 of the present invention;

[0059] Figure 4This is a structural diagram of the series-parallel hybrid model in Embodiment 1 of the present invention;

[0060] Figure 5 This is a structural diagram of the modified model in Embodiment 1 of the present invention;

[0061] Figure 6 Here is the circuit diagram for the two-phase electrode method measurement:

[0062] Figure 7 This is a graph showing the relationship between the conductivity coefficient obtained from Examples 1-5, Comparative Examples 1-15, and the Wiener boundary and the volume content of coarse gravel in the residual soil.

[0063] Figure 8 This is a graph showing the relationship between the conductivity coefficients obtained from the Hashin-Shtrikman boundary and the volume content of coarse gravel in the residual soil in Examples 1-5, Comparative Examples 1-15, and the present invention.

[0064] Among them, Figure 2-5 In the diagram, the arrow indicates the direction of seepage; Figure 2 middle, L This indicates the combined width of the soil and gravel layers in the parallel model; Figure 3 middle, L Indicates the length of the series model along the seepage direction; in Figure 4 middle, L This represents the length of the series-parallel hybrid model along the seepage direction; in Figure 5 middle, This represents the length along the seepage direction after the soil and gravel layers are mixed in the modified model; This represents the length loss in the modified model. Detailed Implementation

[0065] 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 some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0066] Example 1:

[0067] See Figure 1-5 A method for correcting the conductivity of residual soil, wherein the residual soil is assumed to be composed of a mixture of fine-grained soil and coarse-grained gravel; the method for correcting the conductivity of residual soil includes:

[0068] Step S1: Construct a parallel model of the residual soil along the seepage direction and calculate the conductivity of the parallel model. s F-C(P) ;

[0069] A series model of the residual soil was constructed in the vertical seepage direction, and the conductivity of the series model was calculated. s F-C(S) ;

[0070] Step S2: Assuming the volume content of coarse gravel and the volume content of fine soil are the same in both the series and parallel models, construct a series-parallel hybrid model of residual soil and calculate the conductivity of the series-parallel hybrid model. s F-C(SP) ;

[0071] Step S3: Conductivity of the series-parallel hybrid model s F-C(SP) The conductivity of the residual soil was corrected to obtain the corrected conductivity coefficient. s F-CM(SP) .

[0072] In step S1, all the fine soil particles in the residual soil are combined into a soil layer, and all the coarse gravel in the residual soil is combined into a gravel layer.

[0073] In the parallel model of residual soil, the soil layer and the gravel layer are arranged side by side along the seepage direction;

[0074] In the series model of residual soil, the soil layer and the gravel layer are arranged side by side perpendicular to the seepage direction.

[0075] The conductivity of the parallel model s F-C(P) Expressed using equation (1):

[0076] (1);

[0077] The conductivity of the series model s F-C(S) Expressed using equation (2):

[0078] s F-C(S) = C F s F + C C s C (2);

[0079] In equations (1)-(2), s F Indicates the electrical conductivity of fine-grained soil; s C This represents the electrical conductivity of coarse-grained crushed stone. C FThis indicates the volume fraction of fine-grained soil in residual soil. C C This indicates the volume fraction of coarse gravel in residual soil.

[0080] In step S2, the series-parallel hybrid model is a model that combines the series model and the parallel model;

[0081] The conductivity of the series-parallel hybrid model s F-C(SP) Expressed using equation (3):

[0082] (3);

[0083] in, α The structural factor of the residual soil represents the structural proportion of the series model in the series-parallel hybrid model. α The value is 0.5.

[0084] In step S3, the Keller–Frischknecht model is used to evaluate the conductivity of the series-parallel hybrid model. s F-C(SP) The conductivity in the Keller–Frischknecht model is corrected. s Expressed using equation (4):

[0085] (4);

[0086] Conductivity in a series-parallel hybrid model s F-C(SP) ,Will s F-C(SP) Substituting into equation (4), we obtain equation (5):

[0087] (5);

[0088] The modified model is obtained by mixing all soil and gravel layers in the series-parallel hybrid model, and the conductivity of the modified model is measured. s F-CM(SP) ,Will s F-CM(SP) Substituting into equation (4), we obtain equation (6):

[0089] (6);

[0090] Comparing equation (6) with equation (5), we obtain equation (7):

[0091] (7);

[0092] The electrical conductivity of the modified residual soil is obtained using equation (7). s F-CM(SP) ;

[0093] In equations (4)-(7), n This represents porosity in the Keller–Frischknecht model; m This represents the cementation coefficient in the Keller–Frischknecht model, with a value of 2.0; p This represents the saturation parameter in the Keller–Frischknecht model, with a value of 1.5; S r This represents the saturation level in the Keller–Frischknecht model; a This represents specific parameters of fine-grained soil in the Keller–Frischknecht model; r w This represents the pore water resistivity in the Keller–Frischknecht model; n F-C This represents porosity in a series-parallel hybrid model; n F-CM This indicates the porosity in the modified model; n F-CM These are measured values; S r(F-C) This indicates the degree of saturation in a series-parallel hybrid model. S r(F-CM) This indicates the degree of saturation in the correction model.

[0094] Porosity in a series-parallel hybrid model n F-C Expressed using equation (8):

[0095] n F-C = n F C F + n C C C (8);

[0096] In equation (8), n F Indicates the porosity of fine-grained soils; n C Indicates the porosity of coarse-grained crushed stone; n F and n C All values ​​were measured under the same compaction conditions.

[0097] S r(F-C) Expressed using equation (9):

[0098] (9);

[0099] In equation (9), S r(F) Indicates the degree of saturation of fine-grained soil; S r(C) This indicates the saturation level of coarse-grained crushed stone.

[0100] S r(F) Expressed using equation (10):

[0101] (10);

[0102] In equation (10), V w(F) This represents the volume of water in the pores of fine-grained soil. V v(F) This represents the total pore volume of fine-grained soil. oh 1 indicates the water content of fine-grained soil; G F This indicates the proportion of fine-grained soil in the series-parallel hybrid model.

[0103] S r(C) Expressed using equation (11):

[0104] (11);

[0105] In equation (11), V w(C) This represents the volume of water in the pores of coarse-grained gravel; V v(C) This represents the total pore volume of coarse-grained crushed stone; oh 2 indicates the moisture content of coarse-grained crushed stone; G C This indicates the proportion of coarse-grained crushed stone in the series-parallel hybrid model.

[0106] S r(F-CM) Expressed using equation (12):

[0107] (12);

[0108] In equation (12), V w(F-CM) This represents the volume of water in the pores of the residual soil in the corrected model; V v(F-CM)This represents the total pore volume of the residual soil in the modified model; oh 3 indicates the moisture content of the residual soil in the corrected model; G F-CM This indicates the proportion of residual soil in the modified model;

[0109] In equations (10)-(12), oh 1. oh 2. oh 3. The values ​​are the same, all being 10%;

[0110] G F-CM Expressed using equation (13):

[0111] G F-CM = G F C F + G C C C (13).

[0112] Using the residual soil conductivity correction method described in Example 1, the conductivity in the correction model was calculated according to the following experimental procedure.

[0113] Experimental procedure:

[0114] 1) Collect residual soil samples and dry them completely;

[0115] 2) The residual soil samples were screened and classified according to particle size. Sample particles with a diameter of less than 5 mm were classified as fine-grained soil, and sample particles with a diameter between 5 and 20 mm were classified as coarse-grained gravel.

[0116] 3) In the residual soil sample, the volume content of coarse gravel was controlled at 30%, and the moisture content was controlled at 10%;

[0117] 4) In the conductivity coefficient test device, compact three layers of residual soil sample in sequence; the compaction degree is 95%; the height of each sample layer is 0.1 m; add slightly more than 0.1 m of residual soil sample each time, add in three times, and finally remove the excess residual soil sample.

[0118] 5) Connect the conductivity testing device (specifically a glass box, with all four sides along its length made of hollow glass and the two sides along its width made of conductive aluminum; when connecting to the circuit, the two conductive aluminum sides are connected to the wires respectively.) Figure 6Three experiments are conducted in the circuit shown. If the error of the three experimental results is less than 7%, the average of the three experimental results is taken as the experimental result; otherwise, if the error is greater than or equal to 7%, the test is repeated until the error is less than 7%.

[0119] See Figure 6 In experiment 5), the voltage drop Δ between the two electrodes of the conductivity test device was measured using the two-phase electrode method. V And calculate the resistance according to Ohm's law. R The conductivity of the sample is calculated. During the test, the contact surfaces of the conductivity testing device should be coated with a graphite coating with excellent conductivity.

[0120] Example 2:

[0121] Unlike Example 1, the volume content of coarse gravel in the residual soil sample was controlled at 40%.

[0122] Example 3:

[0123] Unlike Example 1, the volume content of coarse gravel in the residual soil sample was controlled at 50%.

[0124] Example 4:

[0125] Unlike Example 1, the volume content of coarse gravel in the residual soil sample was controlled at 60%.

[0126] Example 5:

[0127] Unlike Example 1, the volume content of coarse gravel in the residual soil sample was controlled at 70%.

[0128] Comparative Example 1:

[0129] Unlike Example 1, only a series model was used to calculate the conductivity. s F-C(S) .

[0130] Comparative Example 2:

[0131] Unlike Example 2, only a series model was used to calculate the conductivity. s F-C(S) .

[0132] Comparative Example 3:

[0133] Unlike Example 3, only a series model was used to calculate the conductivity. s F-C(S) .

[0134] Comparative Example 4:

[0135] Unlike Example 4, only a series model was used to calculate the conductivity. s F-C(S) .

[0136] Comparative Example 5:

[0137] Unlike Example 5, only a series model was used to calculate the conductivity. s F-C(S) .

[0138] Comparative Example 6:

[0139] Unlike Example 1, only the parallel model was used to calculate the conductivity. s F-C(P) .

[0140] Comparative Example 7:

[0141] Unlike Example 2, only the parallel model was used to calculate the conductivity. s F-C(P) .

[0142] Comparative Example 8:

[0143] Unlike Example 3, only the parallel model was used to calculate the conductivity. s F-C(P) .

[0144] Comparative Example 9:

[0145] Unlike Example 4, only the parallel model was used to calculate the conductivity. s F-C(P) .

[0146] Comparative Example 10:

[0147] Unlike Example 5, only the parallel model was used to calculate the conductivity. s F-C(P) .

[0148] Comparative Example 11:

[0149] Unlike Example 1, only a series-parallel hybrid model was used to calculate the conductivity. s F-C(SP) .

[0150] Comparative Example 12:

[0151] Unlike Example 2, only a series-parallel hybrid model was used to calculate the conductivity. s F-C(SP) .

[0152] Comparative Example 13:

[0153] Unlike Example 3, only a series-parallel hybrid model was used to calculate the conductivity. s F-C(SP) .

[0154] Comparative Example 14:

[0155] Unlike Example 4, only a series-parallel hybrid model was used to calculate the conductivity. s F-C(SP) .

[0156] Comparative Example 15:

[0157] Unlike Example 5, only a series-parallel hybrid model was used to calculate the conductivity. s F-C(SP) .

[0158] The electrical conductivity of the residual soil samples in the modified model was measured using the experimental procedures described in Examples 1-5. s text Maximum dry density r d Specific gravity of residual soil G F-CM Porosity n F-CM and saturation S r(F-CM) See Table 1 for detailed results.

[0159] Table 1 shows the parameters of the residual soil samples in the modified model measured using the experimental procedures in Examples 1-5.

[0160]

[0161] The electrical conductivity of the residual soil sample, which is a single fine-grained soil, was measured using the experimental procedure described in Example 1. s text Maximum dry density r d The specific gravity of fine-grained soil G F Porosity of fine-grained soil n F and the saturation of fine-grained soil S r(F) See Table 2 for detailed results.

[0162] Table 2 shows the parameters of the residual soil sample as a single fine-grained soil, measured using the experimental procedure in Example 1.

[0163]

[0164] The electrical conductivity of the residual soil sample as a single coarse-grained crushed stone was measured using the experimental procedure in Example 1. s text Maximum dry density r d Specific gravity of coarse gravelG C Porosity of coarse-grained crushed stone n C and the saturation of coarse gravel S r(C) See Table 3 for detailed results.

[0165] Table 3 shows the parameters of the residual soil sample (composed of single coarse-grained crushed stone) measured using the experimental procedure in Example 1.

[0166]

[0167] Based on the measurement data in Tables 1-3 and other given parameter values, the conductivity coefficients of the corresponding models in Examples 1-5 and Comparative Examples 1-15 were calculated. Specific results are shown in Table 4.

[0168] Table 4. Conductivity calculated for each model in Examples 1-5 and Comparative Examples 1-15

[0169]

[0170] Wiener conductivity (abbreviated as W in the diagram) s W The boundary provides a selection interval within which the effective conductivity of the heterogeneous solid should always exist. Its Wiener upper bound equation is the same as the parallel model expression (1), and its Wiener lower bound equation is the same as the series model expression (2). Wiener conductivity s W The following formula is used in this invention:

[0171] s F-C(P) ≥ s W ≥ s F-C(S) .

[0172] The Hashin-Shtrikman boundary (abbreviated as HS in the figure) provides the narrowest isotropic boundary without defining the geometry between the two-phase media (specifically, fine-grained soil and coarse-grained gravel) components. All components in this two-phase media are themselves isotropic and homogeneous. The HS boundary equation is expressed in this invention as follows ( s HS-upper This indicates the upper limit of the conductivity coefficient of HS. s HS-lower (Indicates the lower limit of the conductivity coefficient of HS):

[0173]

[0174] See Figure 7-Figure 8 By comparing Examples 1-5, Comparative Examples 1-15, Wiener boundary, and Hashin-Shtrikman boundary of the present invention, it can be seen that the conductivity coefficient calculated by the modified model of the present invention is closer to the experimental measurement value.

[0175] As shown in Table 3, the conductivity calculated by the series-parallel hybrid model has a relatively large error compared to the experimental measurement, while the conductivity calculated by the modified model is closest to the experimental measurement with the smallest relative error. Specifically, Table 3 shows that the average relative error between the conductivity calculated by the modified model and the experimental measurement is 3.33%, and the maximum relative error is 5.20%.

[0176] Table 5. Cases where the calculated conductivity coefficients of each model in Examples 1-5 and Comparative Examples 1-15 show relative errors compared to experimental measurements.

[0177]

[0178] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for correcting the conductivity of residual soil, characterized in that, The residual soil is assumed to be composed of a mixture of fine-grained soil and coarse-grained gravel; the method for correcting the conductivity of the residual soil includes: Step S1: Construct a parallel model of the residual soil along the seepage direction and calculate the conductivity of the parallel model. σ F-C(P) ; A series model of the residual soil was constructed in the vertical seepage direction, and the conductivity of the series model was calculated. σ F-C(S) ; Step S2: Assuming the volume content of coarse gravel and the volume content of fine soil are the same in both the series and parallel models, construct a series-parallel hybrid model of residual soil and calculate the conductivity of the series-parallel hybrid model. σ F-C(SP) ; Step S3: Conductivity of the series-parallel hybrid model σ F-C(SP) The conductivity of the residual soil was corrected to obtain the corrected conductivity coefficient. σ F-CM(SP) ; The conductivity of the parallel model σ F-C(P) Expressed using equation (1): （1）； The conductivity of the series model σ F-C(S) Expressed using equation (2): σ F-C(S) = C F σ F + C C σ C （2）； In equations (1)-(2), σ F Indicates the electrical conductivity of fine-grained soil; σ C This represents the electrical conductivity of coarse-grained crushed stone. C F This indicates the volume fraction of fine-grained soil in residual soil. C C This indicates the volume fraction of coarse gravel in residual soil; In step S2, the series-parallel hybrid model is a model that combines the series model and the parallel model; The conductivity of the series-parallel hybrid model σ F-C(SP) Expressed using equation (3): （3）； in, α The structural factor of the residual soil represents the structural proportion of the series model in the series-parallel hybrid model; In step S3, the Keller–Frischknecht model is used to evaluate the conductivity of the series-parallel hybrid model. σ F-C(SP) The conductivity in the Keller–Frischknecht model is corrected. σ Expressed using equation (4): （4）； Conductivity in a series-parallel hybrid model σ F-C(SP) ,Will σ F-C(SP) Substituting into equation (4), we obtain equation (5): （5）； The modified model is obtained by mixing all soil and gravel layers in the series-parallel hybrid model, and the conductivity of the modified model is measured. σ F-CM(SP) ,Will σ F-CM(SP) Substituting into equation (4), we obtain equation (6): （6）； Comparing equation (6) with equation (5), we obtain equation (7): （7）； The electrical conductivity of the modified residual soil is obtained using equation (7). σ F-CM(SP) ; In equations (4)-(7), n This represents porosity in the Keller–Frischknecht model; m This represents the cementation coefficient in the Keller–Frischknecht model; p This represents the saturation parameter in the Keller–Frischknecht model; S r This represents the saturation level in the Keller–Frischknecht model; This represents specific parameters of fine-grained soil in the Keller–Frischknecht model; ρ w This represents the pore water resistivity in the Keller–Frischknecht model; n F-C This represents porosity in a series-parallel hybrid model; n F-CM This indicates the porosity in the modified model; n F-CM These are measured values; S r(F-C) This indicates the degree of saturation in a series-parallel hybrid model. S r(F-CM) This indicates the degree of saturation in the correction model.

2. The method for correcting the conductivity of residual soil according to claim 1, characterized in that, In step S1, all the fine soil particles in the residual soil are combined into a soil layer, and all the coarse gravel in the residual soil is combined into a gravel layer. In the parallel model of residual soil, the soil layer and the gravel layer are arranged side by side along the seepage direction; In the series model of residual soil, the soil layer and the gravel layer are arranged side by side perpendicular to the seepage direction.

3. The method for correcting the conductivity of residual soil according to claim 2, characterized in that, Porosity in a series-parallel hybrid model n F-C Expressed using equation (8): n F-C = n F C F + n C C C （8）； In equation (8), n F Indicates the porosity of fine-grained soils; n C Indicates the porosity of coarse-grained crushed stone; n F and n C All values ​​were measured under the same compaction conditions.

4. The method for correcting the conductivity of residual soil according to claim 3, characterized in that, S r(F-C) Expressed using equation (9): （9）； In equation (9), S r(F) Indicates the degree of saturation of fine-grained soil; S r(C) This indicates the saturation level of coarse-grained crushed stone.

5. The method for correcting the conductivity of residual soil according to claim 4, characterized in that, S r(F) Expressed using equation (10): （10）； In equation (10), V w(F) This represents the volume of water in the pores of fine-grained soil. V v(F) This represents the total pore volume of fine-grained soil. ω 1 indicates the water content of fine-grained soil; G F This indicates the proportion of fine-grained soil in the series-parallel hybrid model.

6. The method for correcting the conductivity of residual soil according to claim 5, characterized in that, S r(C) Expressed using equation (11): （11）； In equation (11), V w(C) This represents the volume of water in the pores of coarse-grained gravel; V v(C) This represents the total pore volume of coarse-grained crushed stone; ω 2 indicates the moisture content of coarse-grained crushed stone; G C This indicates the proportion of coarse-grained crushed stone in the series-parallel hybrid model.

7. The method for correcting the conductivity of residual soil according to claim 6, characterized in that, S r(F-CM) Expressed using equation (12): （12）； In equation (12), V w(F-CM) This represents the volume of water in the pores of the residual soil in the corrected model; V v(F-CM) This represents the total pore volume of the residual soil in the modified model; ω 3 indicates the moisture content of the residual soil in the corrected model; G F-CM This indicates the proportion of residual soil in the modified model; In equations (10)-(12), ω 1. ω 2. ω 3. The values ​​are the same; G F -CM Expressed using equation (13): G F -CM = G F C F + G C C C （13）。

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