Unsaturated cohesive soil series-parallel connection combined conductivity calculation method

Abstract

The invention provides a series-parallel connection combined conductivity calculation method for unsaturated cohesive soil. The method mainly comprises the following three parts: firstly, calculating a conductive structure coefficient Fi (i = 1, 2, 3) of a soil body, a volume ratio theta i (i = 1, 2, 3) of a two-phase series connection part, and a volume ratio theta'i (i = 1, 2, 3) of a two-phase parallel connection part; 2, according to the soil unit side length of 1, the soil unit porosity n and the soil unit saturation Sr column formula; thirdly, according to the series-parallel connection relation expression of the resistors of all the parts in the unsaturated clay conductive model, a series-parallel connection combined conductivity structure model of unsaturated cohesive soil is obtained. The method has the advantages that a series-parallel connection combined conductivity calculation method for the unsaturated cohesive soil is established, and an important guarantee is provided for research on application of the unsaturated cohesive soil in engineering.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of soil parameter prediction, and particularly relates to a method for calculating the conductivity of unsaturated cohesive soil in combination of series and parallel connection, which can be used for calculating the conductivity of unsaturated cohesive soil. BACKGROUND

[0002] As an important parameter for studying the mechanical properties of soil, the conductivity of unsaturated cohesive soil is crucial for assessing the water status of soil, predicting the settlement of foundation, designing drainage systems, and monitoring the stability of slopes in civil engineering. Changes in conductivity can reflect the dynamics of water and salt in soil, which is of great significance to ensure the long-term stability and durability of structures. In addition, conductivity data can also be used to guide underground engineering construction, such as tunnel excavation and underground pipeline laying, to avoid engineering problems caused by changes in soil moisture.

[0003] The calculation of the conductivity of unsaturated cohesive soil indeed has certain limitations, especially when considering the complex distribution of water and air in soil. Traditional calculation methods usually assume that the conductive path in soil pores is in series or parallel connection, which simplifies the problem to some extent, but may not accurately reflect the actual situation. In actual unsaturated cohesive soil, the conductive path may be a complex network of series and parallel connection, and further research is needed to improve the calculation model.

[0004] Therefore, it is an urgent technical problem for those skilled in the art to provide a method for calculating the conductivity of unsaturated cohesive soil in combination of series and parallel connection to overcome the above-mentioned deficiencies. SUMMARY

[0005] The application provides a method for calculating the conductivity of unsaturated cohesive soil in combination of series and parallel connection to at least solve the above-mentioned technical problems.

[0006] In order to solve the above-mentioned problems, a method for calculating the conductivity of unsaturated cohesive soil in combination of series and parallel connection is provided, characterized in that it comprises the following steps:

[0007] 1) Assuming that the soil unit is a cube with a side length of l, according to the cross-sectional view and resistance distribution diagram of the soil unit. s1 is the parallel width of the solid phase, l w1 is the parallel width of the liquid phase, l a1 is the parallel width of the gas phase, l w2 is the length of the liquid phase in series, l s2 is the length of the solid phase in series, l w3 is the length of the liquid phase in series, l a2 is the length of the gas phase in series, l a3 is the length of the gas phase in series, l s3L is the width of the solid phase in series, l1 is the width of the liquid phase and solid phase in series, l2 is the width of the liquid phase and gas phase in series, l3 is the width of the gas phase and solid phase in series, and F is defined as the conductive structure coefficient of the soil i (i = 1, 2, 3), the ratio of the width of the path composed of two phases in series to the side length of the whole soil, i.e., the conductive structure coefficient of the liquid phase and the solid phase is F1, the conductive structure coefficient of the liquid phase and the gas phase is F2, and the conductive structure coefficient of the gas phase and the solid phase is F3; the porosity of the soil is n; and the volume ratio of the two-phase parallel part is θ i (i = 1, 2, 3), i.e., the volume ratio of the series connection of the solid phase and the liquid phase is θ1, the volume ratio of the parallel connection of the liquid phase and the gas phase is θ2, and the volume ratio of the parallel connection of the solid phase and the gas phase is θ3; the volume ratio of the two-phase series connection part is θ' i (i = 1, 2, 3), i.e., the volume ratio of the series connection of the solid phase and the liquid phase is θ1', the volume ratio of the series connection of the liquid phase and the gas phase is θ2', and the volume ratio of the series connection of the solid phase and the gas phase is θ3', according to the above definition, formula (1) is obtained:

[0008]

[0009] 2) According to the side length of the soil unit l, the porosity of the soil unit n, and the saturation of the soil unit Sr, formula (2) is obtained:

[0010]

[0011] 3) According to formula (1) and formula (2), the following is obtained:

[0012]

[0013] 4) According to the series-parallel connection relationship of each part of the unsaturated clay conductive model, formula (4) is obtained, wherein the total resistance of the soil unit is R, R s1 is the parallel resistance of the solid phase, R w1 is the parallel resistance of the liquid phase, R a1 is the parallel resistance of the gas phase, R w2 is the liquid phase resistance in series, R s2 is the solid phase resistance in series, R w3 is the liquid phase resistance in series, R a2 is the gas phase resistance in series, R a3 is the gas phase resistance in series, R s3 is the solid phase resistance in series, the soil unit conductivity is ρ, the soil unit conductivity is 1 / ρ, the solid phase conductivity is ρ s , the liquid phase conductivity is ρ w , and the gas phase conductivity is ρ a

[0014]

[0015] 5) the formula (5) unsaturated cohesive soil series parallel combination of conductivity structure model is obtained by substituting (3) into (4) :

[0016]

[0017] Beneficial effects: the effect of the application is to establish the unsaturated cohesive soil series parallel combination of conductivity calculation method, which provides important guarantee for the research of unsaturated cohesive soil in engineering application. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A flow chart of an unsaturated cohesive soil series parallel combination of conductivity calculation method;

[0019] Figure 2 A profile view of a soil unit;

[0020] Figure 3 A soil unit resistance distribution diagram; DETAILED DESCRIPTION

[0021] The unsaturated cohesive soil series parallel combination of conductivity calculation method of the application is described in combination with the accompanying drawings Figure 1 , the accompanying drawings Figure 2 and the accompanying drawings Figure 3 .

[0022] The unsaturated cohesive soil series parallel combination of conductivity calculation method of the application comprises the following steps:

[0023] 1) assuming that the soil unit is a cube with side length l, according to the profile view of the soil unit and the resistance distribution diagram, l s1 is the parallel width of the solid phase, l w1 is the parallel width of the liquid phase, l a1 is the parallel width of the gas phase, l w2 is the length of the liquid phase in series, l s2 is the length of the solid phase in series, l w3 is the length of the liquid phase in series, l a2 is the length of the gas phase in series, l a3 is the length of the gas phase in series, l s3 is the width of the solid phase in series, l1 is the width of the liquid phase and the solid phase in series, l2 is the width of the liquid phase and the gas phase in series, l3 is the width of the gas phase and the solid phase in series, and the conductivity structure coefficient of the soil body is defined as F i (i=1, 2, 3), the ratio of the width of the path composed of two phases in series to the length of the entire soil body, i.e. the conductivity structure coefficient of the liquid phase and the solid phase is F1, the conductivity structure coefficient of the liquid phase and the gas phase is F2, and the conductivity structure coefficient of the gas phase and the solid phase is F3; the porosity of the soil is n; and the volume ratio of the two-phase parallel part is θ i(i = 1, 2, 3), that is, the volume ratio of the series connection of the solid phase and the liquid phase is θ1, the volume ratio of the parallel connection of the liquid phase and the gas phase is θ2, and the volume ratio of the parallel connection of the solid phase and the gas phase is θ3; the volume ratio of the series connection of the two phases is θ' i (i = 1, 2, 3), that is, the volume ratio of the series connection of the solid phase and the liquid phase is θ1', the volume ratio of the series connection of the liquid phase and the gas phase is θ2', and the volume ratio of the series connection of the solid phase and the gas phase is θ3', according to the above definition, formula (1) is obtained:

[0024]

[0025] 2) According to the soil unit edge length l, the soil unit porosity n and the soil unit saturation Sr, formula (2) is obtained:

[0026]

[0027] 3) According to formula (1) and formula (2), formula (3) is obtained:

[0028]

[0029] 4) According to the series-parallel connection relationship of the resistances of each part in the unsaturated clay conductive model, formula (4) is obtained, wherein the total resistance of the soil unit is R, R s1 is the parallel resistance of the solid phase, R w1 is the parallel resistance of the liquid phase, R a1 is the parallel resistance of the gas phase, R w2 is the liquid phase resistance in the series connection, R s2 is the solid phase resistance in the series connection, R w3 is the liquid phase resistance in the series connection, R a2 is the gas phase resistance in the series connection, R a3 is the gas phase resistance in the series connection, R s3 is the solid phase resistance in the series connection, the soil unit conductivity ρ, the soil unit conductivity 1 / ρ, the solid phase conductivity ρ s , the liquid phase conductivity ρ w , and the gas phase conductivity ρ a

[0030]

[0031] 5) Formula (5) unsaturated clay series-parallel combination conductivity structure model is obtained by substituting (3) into (4):

[0032]

[0033] In general, the present application has the following technical effects: an unsaturated clay series-parallel combination conductivity calculation method is established, which provides an important guarantee for the research on the application of unsaturated clay in engineering.

Claims

1. A method for calculating the conductivity of unsaturated cohesive soil by combining series and parallel connections, characterized by, The method comprises the following steps: 1) Assuming that the soil unit is a cube with side length of 1, according to the profile and resistance distribution of the soil unit. s1 is the parallel width of the solid phase, l w1 is the parallel width of the liquid phase, l a1 is the parallel width of the gas phase, l w2 is the length of the liquid phase in series, l s2 is the length of the solid phase in series, l w3 is the length of the liquid phase in series, l a2 is the length of the gas phase in series, l a3 is the length of the gas phase in series, l s3 is the width of the solid phase in series, l1 is the width of the liquid phase and the solid phase in series, l2 is the width of the liquid phase and the gas phase in series, l3 is the width of the gas phase and the solid phase in series, and the conductive structure coefficient of the soil body is defined as F i (i = 1, 2, 3), the width ratio of the path composed of two-phase series to the entire soil body side length, that is, the conductive structure coefficient of the liquid phase and the solid phase is F1, the conductive structure coefficient of the liquid phase and the gas phase is F2, and the conductive structure coefficient of the gas phase and the solid phase is F3; the porosity of the soil is n; the volume ratio of the two-phase parallel part is θ i (i = 1, 2, 3), that is, the volume ratio of the series of the solid phase and the liquid phase is θ1, the volume ratio of the parallel of the liquid phase and the gas phase is θ2, and the volume ratio of the parallel of the solid phase and the gas phase is θ3; the volume ratio of the two-phase series part is θ′ i (i = 1, 2, 3), that is, the volume ratio of the series of the solid phase and the liquid phase is θ1′, the volume ratio of the series of the liquid phase and the gas phase is θ2′, and the volume ratio of the series of the solid phase and the gas phase is θ3′, according to the above definition, formula (1) is obtained: 2) According to the soil unit side length 1, the soil unit porosity n, and the soil unit saturation Sr, formula (2) is obtained: 3) According to formula (1) and formula (2), formula (3) is obtained: 4) From the series and parallel relationship of the resistances in the unsaturated clay conduction model, equation (4) is obtained, where R is the total resistance of the soil element, R s1 is the parallel resistance of the solid phase, w1 is the parallel resistance of the liquid phase, a1 is the parallel resistance of the gas phase, w2 is the liquid phase resistance in series, s2 is the solid phase resistance in series, w3 is the liquid phase resistance in series, a2 is the gas phase resistance in series, a3 is the gas phase resistance in series, s3 is the solid phase resistance in series, the soil element conductivity p, the soil element conductivity 1 / p, the solid phase conductivity p s , the liquid phase conductivity p w , the gas phase conductivity p a 5) Formula (5) is obtained by substituting (3) into (4), which is an unsaturated cohesive soil series-parallel combination conductivity structure model:

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