Method for determining consolidation degree of soft soil foundation reinforced by composite pile by considering anisotropy of soft soil

Abstract

The invention discloses a method for determining the consolidation degree of a soft soil foundation reinforced by a composite pile by considering the anisotropy of soft soil, and relates to the field of soil mechanics. Obtaining a yield function combining a dimension hardening rule and a rotation hardening rule; a calculation formula for describing the nonlinear seepage behavior of soft soil around the composite pile is obtained; the calculation formula of the nonlinear seepage behavior is used for representing the nonlinear relationship between the void ratio and the permeability coefficient; the yield function, a calculation formula for describing the nonlinear seepage behavior and a calculation formula for the average consolidation degree are combined, and the average consolidation degree of the composite pile reinforced soft soil foundation under different loading modes is solved; the calculation formula of the average consolidation degree is constructed based on the influence of the anisotropic behavior, the nonlinear seepage behavior and the disturbance on the horizontal permeability of the smearing belt. According to the method, the determination precision of the average consolidation degree of the composite pile reinforced soft soil foundation is improved.

Description

Technical Field

[0001] This invention relates to the field of soil mechanics, and in particular to a method for determining the degree of consolidation of composite piles for reinforcing soft soil foundations, taking into account the anisotropy of soft soil. Background Technology

[0002] In recent years, various foundation improvement technologies have been developed to enhance the stability and bearing capacity of soft soil foundations. Composite pile improvement methods outperform traditional methods such as crushed stone columns. When exploring the failure modes, bearing mechanisms, and design methods of composite pile foundation reinforcement, theoretical analysis is an effective tool for studying the consolidation process and excess pore water pressure dissipation of composite pile foundations. Theoretical models typically assume a circular cross-section, but the cross-sectional shape of composite piles in actual engineering often exhibits diverse characteristics. To address this issue, researchers proposed the ring equivalent method, which has been used in subsequent studies to derive analytical solutions for the consolidation of composite foundations with non-circular cross-section piles. To further refine the model, researchers also explored the clogging effect of gravel crust varying with time and depth, developing analytical solutions that comprehensively consider these clogging effects, thereby predicting the consolidation behavior of composite foundations.

[0003] During consolidation, a nonlinear relationship exists between porosity, effective stress, and soil permeability coefficient. This nonlinear relationship has a significant impact on the consolidation behavior of composite foundations. To accurately capture this nonlinear relationship, researchers have conducted extensive studies to explore the nonlinear consolidation process in composite foundations.

[0004] Soft soil is a complex engineering material with high compressibility. However, due to its properties, accurately predicting the mean degree of consolidation of soft soil presents a significant challenge. Early constitutive models were often simplified based on the isotropic elastoplastic behavior of soft soil, leading to serious distortions in the prediction of the mean degree of consolidation of composite pile-reinforced soft soil foundations. Summary of the Invention

[0005] Therefore, it is necessary to provide a method for determining the degree of consolidation of composite pile-reinforced soft soil foundations that considers the anisotropy of soft soil, addressing the aforementioned technical problems. This method improves the accuracy of determining the average degree of consolidation of composite pile-reinforced soft soil foundations.

[0006] The present invention adopts the following technical solution: This invention provides a method for determining the degree of consolidation of composite piles for soft soil foundation reinforcement considering the anisotropy of soft soil, comprising: Obtain the yield function that combines the size hardening law and the rotational hardening law; the yield surface in the yield function is represented by an inclined ellipse to represent the anisotropic behavior of the soft soil around the composite pile; the size hardening law changes the size of the yield surface by adjusting the hardening parameters; the rotational hardening law is used to describe the rotational characteristics of the yield surface. Obtain the calculation formula describing the nonlinear seepage behavior of soft soil around composite piles; the calculation formula for nonlinear seepage behavior is used to express the nonlinear relationship between void ratio and permeability coefficient; The formulas for calculating the yield function, nonlinear seepage behavior, and average degree of consolidation are combined to solve for the average degree of consolidation of composite pile-reinforced soft soil foundations under different loading methods. The formula for calculating the average degree of consolidation is based on the effects of anisotropic behavior, nonlinear seepage behavior, and disturbance on the horizontal permeability of the coating strip.

[0007] Preferably, the formula corresponding to the dimension hardening law is: ; in, To determine the hardening parameters for the yield curve size, v For specific volume, The compression index, For total volumetric strain, for The differential; The formula corresponding to the rotational hardening law is: ; in, To control the rotational hardening parameters of the yield curve inclination angle, and It is control Two positive definite constants, For plastic volumetric strain, The range of values ​​for is [ , ], for The differential; The yield function is: ; in, f Let be the yield function. g Let be the plastic potential function. It is a deviatoric stress. M The critical stress ratio. For the average effective stress, To determine the hardening parameters for the yield curve size, Rotational hardening parameters are used to control the tilt angle of the yield curve.

[0008] Preferably, the calculation formula describing the nonlinear seepage behavior of the soft soil around the composite pile is as follows: ; in, Given the current porosity, The initial void ratio, The initial vertical permeability coefficient of the soft soil surrounding the composite pile is given. Let be the initial horizontal permeability coefficient of the soft soil surrounding the composite pile. The horizontal permeability coefficient of undisturbed soil. The vertical permeability coefficient of the soft soil surrounding the composite pile is given. Let be the initial vertical permeability coefficient of the soft soil surrounding the composite pile. denoted as the initial horizontal permeability coefficient of the soft soil surrounding the composite pile.

[0009] Preferably, the composite pile reinforcement of soft soil foundation includes a rigid core, a gravel shell, and soft soil surrounding the composite pile; the formula for calculating the average degree of consolidation is: ; in, The average degree of consolidation for composite pile reinforcement of soft soil foundations, For depth z Time t Variable additional loads, H This represents the total thickness of the soft soil surrounding the composite pile. , , , , , , , , = , , For depth z The final additional load at the location, The average volume compressibility factor during the consolidation process. Let be the area of ​​the gravel shell. This represents the area of ​​the soft soil surrounding the composite pile. The area of ​​a unit cell. , The density of water, , The initial average effective stress of the soft soil surrounding the composite pile is given. , Let be the slope of the canonical consolidation line in the plane. The final volume compression factor, The initial vertical permeability index is the soft soil surrounding the composite pile. Let be the permeability coefficient of the gravel shell. It is the square of the unit cell radius. Let be the initial vertical permeability coefficient of the soft soil surrounding the composite pile. Let be the initial horizontal permeability coefficient of the soft soil surrounding the composite pile. The initial average effective stress of the soft soil surrounding the composite pile is given. The initial horizontal permeability index is the soft soil surrounding the composite pile. To determine the effect of disturbance on the horizontal penetration rate of the coating strip. , It is the initial volume compressibility factor during the consolidation process of soft soil around composite piles. The average volumetric compressibility factor during the consolidation of soft soil around composite piles. , = , Let be the area of ​​the rigid core. , The initial volume compressibility index, The volumetric compression index of a rigid core. , The volumetric compressibility index of the gravel shell is . To add the final load.

[0010] Preferably, the average volume compressibility factor is: ; in, The average volume compressibility factor. v For specific volume, The compression index, The inflation index, Critical stress ratio Rotational hardening parameters are used to control the slope angle of the yield curve. for initial value, and To control Two positive definite constants, , This is the coefficient of earth pressure at rest.

[0011] Preferably, the formula for calculating the effect of disturbance on the horizontal penetration rate of the coating strip is: ; in, , , , , The permeability coefficient of the coating area varies with the radius. A changing function, The radius of the composite pile, The radius of the unit cell, r Let be the radius.

[0012] Preferably, the different loading methods include instantaneous load and slope loading; the yield function, the calculation formula describing nonlinear seepage behavior, and the calculation formula for the average degree of consolidation are combined to solve for the average degree of consolidation of the composite pile-reinforced soft soil foundation under different loading methods, specifically including: The equations corresponding to instantaneous load, the calculation formula describing nonlinear seepage behavior, and the calculation formula for average degree of consolidation are combined to solve for the average degree of consolidation of composite pile-reinforced soft soil foundation under instantaneous load. By combining the equations corresponding to slope loading, the calculation formula describing nonlinear seepage behavior, and the calculation formula for average degree of consolidation, the average degree of consolidation of the composite pile-reinforced soft soil foundation under slope loading is solved.

[0013] Preferably, the equation combination corresponding to the instantaneous load is: ; ; ; ; in, For depth z Time t Variable additional loads, This represents the total stress at the top boundary of the composite pile-reinforced soft soil foundation. These represent the total stress at the bottom boundary of the composite pile-reinforced soft soil foundation. H This represents the total thickness of the soft soil surrounding the composite pile. , , , , ; The equation combination corresponding to the slope load is: ; ; ; ; in, This represents the starting time of the slope loading.

[0014] This invention provides a device for determining the degree of consolidation of composite piles for soft soil foundation reinforcement, taking into account the anisotropy of soft soil, comprising: The first acquisition module is used to acquire the yield function that combines the size hardening law and the rotational hardening law; the yield surface in the yield function is represented by an inclined ellipse to represent the anisotropic behavior of the soft soil around the composite pile; the size hardening law changes the size of the yield surface by adjusting the hardening parameters; the rotational hardening law is used to describe the rotational characteristics of the yield surface. The second acquisition module is used to acquire the calculation formula describing the nonlinear seepage behavior of soft soil around composite piles; the calculation formula for nonlinear seepage behavior is used to represent the nonlinear relationship between void ratio and permeability coefficient. The determination module is used to simultaneously solve the average degree of consolidation of composite pile-reinforced soft soil foundations under different loading methods by combining the yield function, the calculation formula describing nonlinear seepage behavior, and the calculation formula for the average degree of consolidation. The calculation formula for the average degree of consolidation is constructed based on the anisotropic behavior, the nonlinear seepage behavior, and the influence of disturbance on the horizontal permeability of the coating strip.

[0015] This invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for determining the degree of consolidation of composite pile-reinforced soft soil foundations considering the anisotropy of soft soil.

[0016] The present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-mentioned method for determining the degree of consolidation of composite pile reinforcement for soft soil foundation considering the anisotropy of soft soil.

[0017] The above-mentioned at least one technical solution adopted in this invention can achieve the following beneficial effects: This method obtains a yield function combining dimensional hardening and rotational hardening laws. The yield surface in the yield function is represented by an inclined ellipse to depict the anisotropic behavior of the soft soil surrounding the composite pile. Dimensional hardening alters the size of the yield surface by adjusting hardening parameters. Rotational hardening describes the rotational characteristics of the yield surface, and the inclined elliptical yield surface accurately simulates the anisotropic behavior of the soft soil surrounding the composite pile, significantly improving the physical fit between the soil yield condition and the stress-strain relationship. A calculation formula describing the nonlinear seepage behavior of the soft soil surrounding the composite pile is obtained. This formula represents the nonlinear relationship between void ratio and permeability coefficient, accurately reflecting the dynamic attenuation of permeability with void ratio during soft soil consolidation. The yield function, the calculation formula describing nonlinear seepage behavior, and the formula for calculating the average degree of consolidation are combined to solve for the average degree of consolidation of the composite pile-reinforced soft soil foundation under different loading methods. The formula for calculating the average degree of consolidation is constructed based on anisotropic behavior, nonlinear seepage behavior, and the influence of disturbance on the horizontal permeability of the coating strip. This method improves the accuracy of determining the average degree of consolidation of the composite pile-reinforced soft soil foundation. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 A schematic diagram of the process for determining the degree of consolidation of a composite pile for reinforcing a soft soil foundation, taking into account the anisotropy of soft soil, is provided for this invention. Figure 2 A schematic diagram of an equivalent circular unit cell for a composite pile foundation provided by the present invention; Figure 3 This is a schematic diagram of the ring equivalent method provided by the present invention; Figure 4 This is a schematic diagram of the yield surface in the plane of the S-CLAY1 model provided by the present invention; Figure 5 The present invention provides two solutions for loading schemes, wherein (a) is a schematic diagram of instantaneous loading and (b) is a schematic diagram of ramp loading; Figure 6 A comparison chart showing the average degree of consolidation predicted by the method of this invention and the prediction results of multiple established analytical models; Figure 7 The curves showing the average degree of consolidation as a function of time under different critical friction angles provided by this invention; Figure 8 The following are schematic diagrams showing the variation of the main parameters of the present invention with the friction angle at the critical state. (a) is a curve showing the variation of the stress ratio with the friction angle at the critical state, (b) is a curve showing the variation of the rotational hardening parameter with the friction angle at the critical state, and (c) is a curve showing the variation of the average volume compressibility factor with the friction angle at the critical state. Figure 9 The distribution diagram of porosity overpressure along depth in composite formations under different critical friction angles provided by this invention; Figure 10 The curves showing the change of average degree of consolidation with time under different conditions provided by the present invention; Figure 11 A schematic diagram of the average volume compressibility factor as a function of angle, provided by the present invention; Figure 12 This is a schematic diagram illustrating the distribution of excess pore pressure along depth in composite formations under different conditions, as provided by the present invention. Figure 13 The curves showing the change of average degree of consolidation with time under different conditions provided by the present invention; Figure 14 This is a schematic diagram illustrating the changes in the main parameters provided by the present invention, wherein (a) is a... and Follow Figure (b) shows the variation curve of the average volume compressibility factor with... A schematic diagram of the change curve; Figure 15This is a schematic diagram illustrating the distribution of excess pore pressure along depth in composite formations under different conditions, as provided by the present invention. Figure 16 A schematic diagram of a device for determining the degree of consolidation of a composite pile for reinforcing a soft soil foundation, taking into account the anisotropy of soft soil, provided by the present invention; Figure 17 This is a schematic diagram of a computer device for determining the degree of consolidation of a composite pile foundation for soft soil reinforcement, which takes into account the anisotropy of soft soil, as provided by the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] The server mentioned in this invention can be a server set up on a business platform, or a device such as a desktop computer or laptop computer capable of executing the solution of this invention. For ease of explanation, the following description will only focus on the server as the executing entity.

[0022] The technical solutions provided by the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of a method for determining the degree of consolidation of a composite pile for reinforcing soft soil foundation, taking into account the anisotropy of soft soil, according to the present invention. The method specifically includes the following steps: S101: Obtain the yield function combining the size hardening law and the rotational hardening law; the yield surface in the yield function is represented by an inclined ellipse to show the anisotropic behavior of the soft soil around the composite pile; the size hardening law changes the size of the yield surface by adjusting the hardening parameters; the rotational hardening law is used to describe the rotational characteristics of the yield surface.

[0024] In composite pile foundations, the piles can be arranged in various ways, such as triangles, squares, or hexagons. However, for ease of analysis, these different layouts can be simplified to equivalent circular unit cells. This invention takes a single pile and its surrounding influence zone as the object of analysis. Figure 2 This is a schematic diagram of an equivalent circular unit cell for composite pile reinforcement of soft soil foundations provided by the present invention, as shown below. Figure 2 As shown, Figure 2In this designation, "pervious" refers to the permeable layer, "anisotropic soft clay" to the anisotropic soft soil, "gravel shell" to the gravel shell, "stiff core" to the rigid core, "smear zone" to the smear zone, "virtual hole" to the virtual hole, and "impervious" to the impervious layer. A typical unit cell consists of the composite pile and the soil layers within its influence zone. This composite pile is composed of a central rigid core and an outer gravel shell. Figure 3 This is a schematic diagram of the ring equivalent method provided by the present invention, such as... Figure 3 As shown, the gravel shell is a gravel shell, and the stiff core is a rigid core. Using the toroidal equivalent method, the non-circular cross-section of the composite pile can be converted into an equivalent circle for analysis. This method requires that the pile's perimeter and cross-sectional area remain unchanged during the conversion process; therefore, virtual voids will inevitably be generated after the conversion. The composite pile is surrounded by soft soil exhibiting anisotropic elastoplastic behavior. Based on the distance from the gravel shell, the surrounding soil layers are divided into a smeared zone and an undisturbed zone.

[0025] To simplify the problem and arrive at a solution, this invention makes the following assumptions: (1) Assume that the properties of the composite foundation are uniform throughout the depth range.

[0026] (2) The gravel and the surrounding soil are fully saturated and the water is incompressible.

[0027] (3) It is assumed that the smeared area and the undisturbed soil have the same compressibility.

[0028] (4) It is assumed that the rigid core, gravel shell, and surrounding soil all experience the same vertical strain at any given depth. This iso-strain assumption has been widely adopted and validated in the development of composite foundation consolidation models. Compared to the free strain assumption under rigid load conditions (such as cases where there are vertical deformation constraints, such as foundation slabs or embankments), this assumption is more applicable. The effectiveness of the iso-strain assumption increases with the increase of the load platform stiffness.

[0029] (5) The flow of water in the gravel and the surrounding soil follows Darcy's law.

[0030] (6) Vertical and horizontal seepage are taken into account, and the amount of water flowing into the gravel shell is equal to the amount of water flowing out of the gravel shell, thus ensuring the continuity of water flow.

[0031] (7) The plastic strain of soil is determined by relevant flow rules and regularity hypothesis. For one-dimensional consolidation, only the plastic strain in the vertical direction is considered and the plastic strain in the horizontal direction is ignored.

[0032] At a specific depth zThe additional load applied at this location is supported by a rigid core, a gravel shell, and the soft soil surrounding the composite pile. Therefore, at this depth... z The equilibrium equation at point is formula (1):

[0033] (1); in, The average additional stress of the rigid core, Let be the area of ​​the rigid core. The average additional stress of the gravel shell, The average excess pore water pressure in the gravel shell. Let be the area of ​​the gravel shell. The average additional stress in the soft soil surrounding the composite pile. The average excess pore water pressure in the soft soil surrounding the composite pile. This represents the area of ​​the soft soil surrounding the composite pile. For depth z Time t Variable additional loads, This represents the area of ​​a unit cell.

[0034] The formula for calculating the average excess pore water pressure in the soft soil surrounding the composite pile is formula (2): (2); in, The average excess pore water pressure in the soft soil surrounding the composite pile. soft soil around composite piles t Always in depth z radius r Excess pore water pressure at the location, The radius of the composite pile, denoted as the radius of the unit cell.

[0035] The average pore water pressure in a unit cell is given by formula (3): (3); in, The average pore water pressure in a unit cell. , = , The average excess pore water pressure in the gravel shell.

[0036] Based on formula (3), formula (1) is simplified to formula (4): (4); in, The ratio of the area of ​​the rigid core to the area of ​​the unit cell. = , For depth z Timet Variable additional loads.

[0037] Considering both vertical and horizontal seepage, and based on the law of conservation of mass, the soil consolidation equation is derived as formula (5): (5); in, r Let be the radius of the soft soil surrounding the composite pile. This represents the horizontal permeability coefficient of the soft soil surrounding the composite pile. , The density of water, This represents the vertical permeability coefficient of the soft soil surrounding the composite pile. Indicates the horizontal permeability coefficient of undisturbed soil. It is a function of the radial distance from the gravel shell. , This represents the minimum horizontal penetration coefficient within the application area. This represents the vertical strain of the unit cell.

[0038] According to the assumption of equal strain, the rigid core, gravel shell, and soft soil around the composite pile have the same vertical strain caused by the additional load at depth, as given by formula (6): (6); in, Indicates the vertical strain of the unit cell. , and The volumetric compressibility indexes are for rigid core, gravel shell, and composite pile perimeter soft soil, respectively.

[0039] The mechanical behavior of the surrounding soil is described using the same yield function as the S-CLAY1 model.

[0040] like Figure 4 As shown, the yield function has an inclined elliptical shape and combines two hardening laws—size hardening and rotational hardening—to account for the change in the intrinsic anisotropy of the material with subsequent loading. In the triaxial stress space, the relevant flow rules are followed, and the yield function is given by formula (7):

[0041] (7); in, f Let be the yield function. g Let be the plastic potential function. It is a deviatoric stress. = , For vertical effective stress, For horizontal effective stress, in soft soil surrounding composite piles , = , The coefficient of earth pressure at rest can be estimated using the Jaky formula. , The friction angle is the critical state. For the average effective stress, = = , To determine the rotational hardening parameters for the yield curve size, The critical stress ratio. It is a hardening parameter that controls the slope angle of the yield curve.

[0042] This invention follows the classical notation conventions of soil mechanics, that is, compression is regarded as normal stress. Figure 4 This is a schematic diagram of the yield surface in the plane of the S-CLAY1 model provided by the present invention, as shown below. Figure 4 As shown, The critical stress ratio. Known as the Critical State Line (CSL), it can be derived from the critical friction angle according to the Mohr-Coulomb criterion. This parameter can be represented geometrically as the tangent to line OA, where point A is the line... The intersection point with the yield curve lies precisely on the vertical tangent of the yield curve. The initial yield surface is the initial yield surface, and the current yield surface is the current yield surface. Increasing this parameter value will make the yield curve more vertical. The tendency of the yield curve plays an important role in capturing the anisotropic behavior of soft soil within a unit cell. These are the hardening parameters that determine the current yield curve size. It is a hardening parameter that determines the initial yield curve size, and is defined geometrically as the stress ratio. The average effective stress at the intersection with the yield surface. According to the yield function formula (7), Represented as formula (8):

[0043] (8); in, The stress ratio is given.

[0044] S-CLAY1 introduces two hardening laws. The first is the size hardening law, which is determined by changing parameters. The value is used to adjust the size of the yield surface. In S-CLAY1, it is assumed that... It is only related to plastic volumetric strain, which is similar to the improved Cam-Clay model.

[0045] The differential is given by formula (9): (9); in, For specific volume, = , The compression index is defined as follows: The slope of the line of normal consolidation in a plane. The inflation index is defined as follows: The slope of the normal expansion line in a plane. For plastic volumetric strain , For vertical plastic strain, For horizontal plastic strain, For total volumetric strain.

[0046] The second hardening law describes the rotational hardening properties of the yield surface, which are closely related to anisotropic evolution. In triaxial stress space, the rotational hardening law derived from observations of Otaniemi clay in Finland is formula (10):

[0047] (10); in, Represents plastic shear strain. , It is the plastic deviatoric stress increment vector in triaxial stress space. , and It is control Two positive definite constants, For horizontal plastic strain increments, For the strain increment of the plastic body, This represents the vertical plastic strain increment.

[0048] Formula (10) shows and The range of values ​​is to As the increment of plastic volumetric strain increases, Gradually approaching the target value Simultaneously, as the increment of plastic shear strain increases, It is also gradually approaching the target value. . Controlling The absolute rate of change toward the current target value. The relative contributions of plastic shear strain and plastic volumetric strain to the overall objective value are controlled. Macaulay brackets ensure the model remains within the critical state line. Dry side ( Prediction of yield time The rationality of this. Therefore, when hour , and when hour It is the absolute value of plastic shear strain.

[0049] The plastic strain is determined by the correlation flow rule and the regularity assumption, as shown in formulas (11) and (12): (11); (12); in, For positive plastic multipliers, f is the yield function.

[0050] In one-dimensional consolidation analysis, only the plastic strain in the vertical direction is considered, while the plastic strain in the horizontal direction is neglected. Therefore, and The ratio of the two is determined to be 2 / 3. Using formulas (7), (11), and (12), formula (13) can be derived as follows:

[0051] (13); The equation (10) for the rotational hardening law can be simplified to equation (14): (14); Initially, the soil around the composite pile was in a state of... State. Then, according to formula (13), determine... The initial value is given by formula (15):

[0052] (15); in, .

[0053] During the consolidation process The value will vary with the mean effective stress and rotation hardening parameters It changes with the change. Therefore, according to formula (8), it can be derived that The differential expression is given by formula (16):

[0054] (16); in, This represents the average effective stress.

[0055] Adding formulas (9), (14), and (16), we get formula (17): (17); Then, in t Moment, Depth z The volumetric compressibility index of the soft soil surrounding the composite pile is calculated according to formulas (18) and (19). Formula (18) is as follows: (18); in, For the soft soil around the composite pile in time t depth z The volume compressibility index at that location, for t Time depth z The average effective stress of the soft soil surrounding the composite pile at the location, for t Time depth z The volume compression factor of the infinitely large position.

[0056] Formula (19) is: (19); In this invention, The volume compressibility factor is infinite. for t Time depth z Rotational hardening parameters at the location.

[0057] According to formulas (18) and (19), the soft soil around the composite pile in time t The volume compressibility index can be obtained from the initial volume compressibility index using formula (20): (20); in, For the soft soil around the composite pile in time t depth z The volume compressibility index at that location, This represents the initial average effective stress in the soft soil surrounding the composite pile. Indicates the initial volume compressibility factor. The initial volume compressibility index and the initial volume compressibility factor are given. For formula (21): = (twenty one); Using formulas (4), (6), and (20), we obtain formula (22): (twenty two); in, The average effective stress of the soil surrounding the composite pile is... The initial average effective stress of the soil surrounding the composite pile is given. The average additional stress of the soil surrounding the composite pile. , The ratio of the area of ​​the rigid core to the unit cell. The ratio of the area of ​​the gravel shell to the area of ​​the unit cell. , The initial volume compressibility index, The volumetric compression index of a rigid core. , The volumetric compressibility index of the gravel shell is . The average pore water pressure in a unit cell. This represents the area ratio of the soil surrounding the composite pile to the unit cell.

[0058] The average effective stress of the soil is obtained by formula (22) as formula (23): (twenty three); The partial derivative with respect to time is given by formula (24): (twenty four); During the consolidation process of the surrounding soil, the plastic volumetric strain increases with the settlement of the composite foundation, while the rotational hardening parameter gradually reaches its final value. The final value of the rotational hardening parameter can be obtained through formula (13). The calculation yields the result, which is formula (25):

[0059] (25); in, This represents the final value of the rotational hardening parameter.

[0060] By substituting (25) into formulas (17) and (18), the final value obtained is formula (26): (26); in, This is the final volume compression factor.

[0061] The average volumetric compressibility coefficient during the consolidation of soft soil around composite piles is given by formula (27): (27); in, The average volume compressibility factor. The initial volume compressibility factor. , The coefficient of earth pressure at rest. v For specific volume, The compression index, k The inflation index, Critical stress ratio for initial value, and To control Two positive definite constants.

[0062] By combining formulas (17), (18), (23), and (24), and replacing them with the average value... The partial derivative of the total volumetric strain with respect to time is derived as formula (28): (28); in, For total volumetric strain, , , , For the final additional load, , , = , , , The initial volume compressibility index, is the volume compressibility index of the gravel shell.

[0063] The pore pressure at the interface between the gravel shell and the soft soil surrounding the composite piles is continuous. Due to the symmetry of the composite pile arrangement, the horizontal boundary of the entire cell is impermeable. Therefore, the continuity condition and boundary condition of a cell are given by formula (29):

[0064] (29); By applying formula (5) from Equation to Integrating and using the boundary condition formula (29), we can obtain formula (30) as follows: (30); in, The excess pore water pressure in the soft soil surrounding the composite pile. The average excess pore water pressure in the gravel shell. The density of water, The horizontal permeability coefficient of the soft soil surrounding the composite pile is given. The vertical permeability coefficient of the soil surrounding the composite pile is given. The average excess pore water pressure in the soft soil surrounding the composite pile. It is a function of the permeability coefficient of the coating area as a function of the radius.

[0065] By combining the continuity condition in formula (29) and refining formula (30) from... arrive By performing integral calculations, the excess pore water pressure of the soft soil around the composite pile can be expressed as formula (31): (31); in, The excess pore water pressure in the soft soil surrounding the composite pile. , , The range of values ​​for is [ , ], and They have the same meaning, but different signs for the independent variables.

[0066] Substituting formula (31) into formula (2), we can obtain the average excess pore water pressure of the soil as formula (32): (32); in, , , , This reflects the impact of disturbance on the horizontal penetration rate of the coating strip.

[0067] As can be seen from the above derivation process, Only depends on The distribution pattern.

[0068] Assuming that the amount of water flowing into the gravel shell through the smearing zone is equal to the amount of water flowing out of the gravel shell, the mass conservation condition is given by formula (33): (33); in, The penetration coefficient of the coating area. Let be the permeability coefficient of the gravel shell. This represents the cross-sectional area of ​​the gravel shell.

[0069] Adding equations (30) and (33), we get equation (34): (34); Using formulas (32) and (34), the average excess pore water pressure of the soft soil around the composite pile can be expressed as the average excess pore water pressure of the gravel shell, which is given by formula (35). (35); Substituting equation (35) into (34), we obtain formula (36): (36); Using equation (35) Offset from formula (3) , which is formula (37): (37); Substituting equation (37) into (28), we obtain formula (38) as follows: (38); During the consolidation process of the composite foundation, the nonlinear compressibility and permeability of the soft soil around the composite piles are considered by formulas (39) and (40), respectively: (39); in, Given the current porosity, The initial void ratio, The compression index is the soft soil surrounding the composite pile. The slope of the canonical consolidation line in the plane .

[0070] S102: Obtain the calculation formula describing the nonlinear seepage behavior of soft soil around composite piles; the calculation formula for nonlinear seepage behavior is used to express the nonlinear relationship between void ratio and permeability coefficient.

[0071] The formula corresponding to the nonlinear seepage behavior of soft soil around composite piles is formula (40): (40); in, Given the current porosity, The initial void ratio, The initial vertical permeability coefficient of the soft soil surrounding the composite pile is given. Let be the initial horizontal permeability coefficient of the soft soil surrounding the composite pile. The horizontal permeability coefficient of undisturbed soil. The vertical permeability coefficient of the soft soil surrounding the composite pile is given. Let be the initial vertical permeability coefficient of the soft soil surrounding the composite pile. denoted as the initial horizontal permeability coefficient of the soft soil surrounding the composite pile.

[0072] Solve from formula (40) and Substitute this into the formula for calculating the average degree of consolidation.

[0073] Combining formulas (39) and (40), we can obtain the expressions for the horizontal and vertical permeability coefficients of the soil as formulas (41) and (42): (41); (42); Substituting formulas (38), (41), and (42) into equation (36), we obtain formula (43): (43); in, , , .

[0074] The upper boundary of the composite foundation is permeable, and the lower boundary is impermeable. Therefore, the condition for obtaining the vertical boundary is given by formula (44): (44); Initially, no vertical deformation occurs in the composite foundation. The overload is entirely borne by the pore pressure in the gravel and soil. Therefore, the initial condition is given by formula (45):

[0075] (45); According to the vertical boundary condition equation (44), the average excess pore water pressure in the gravel shell can be estimated by the variable separation method, resulting in formula (46): (46); in, , For the first m A time function, z For depth, .

[0076] The partial derivative of the additional load over time can be expressed by the Fourier sine expansion as formula (47): (47); in, .

[0077] S103: Combine the yield function, the calculation formula describing nonlinear seepage behavior, and the calculation formula for the average degree of consolidation to solve the average degree of consolidation of composite pile-reinforced soft soil foundations under different loading methods; the calculation formula for the average degree of consolidation is constructed based on the influence of anisotropic behavior, nonlinear seepage behavior, and disturbance on the horizontal permeability of the coating strip.

[0078] Substituting formulas (46) and (47) into equation (43), we obtain formula (48): (48); Using the initial condition equation (45), the average excess pore water pressure in the gravel shell is solved by equations (46) and (48) as equation (49): (49); in, , .

[0079] The average pore pressure in a unit cell can be solved by substituting equation (49) into equation (37), and the average pore water pressure in a unit cell is given by equation (50): (50); in, is the average pore water pressure in a unit cell.

[0080] As the ratio of effective stress to total stress in the entire composite foundation, the average degree of consolidation can be derived from formula (50), which is formula (51): (51); Furthermore, the solutions to equations (49)-(50) can be obtained through different loading schemes. Figure 5 The solutions to the two loading schemes provided by this invention are as follows: Figure 5 As shown, Figure 5 Figure (a) in the diagram is a schematic diagram of instantaneous loading. Figure 5 Figure (b) in the diagram is a schematic diagram of slope loading.

[0081] Under instantaneous load conditions, the total stress is constant and is assumed to vary linearly along the depth. Therefore, a combination of equations as shown in equations (52)-(55) can be obtained:

[0082] (52); (53); (54); (55); in, This represents the total stress at the top boundary of the composite foundation. These represent the total stress at the bottom boundary of the composite foundation, .

[0083] Substituting the multiple equations shown in formulas (52)-(55) into formulas (49)-(51), the average excess pore pressure in the gravel crust, the average excess pore water pressure in the composite strata, and the average degree of consolidation under instantaneous load are derived as formulas (56), (57), and (58): (56); (57); (58); Under slope loading, the total stress is zero at the initial moment and increases linearly with time until a certain moment. .exist In this stage, the formula combination corresponding to formula (59) - formula (62) is:

[0084] (59); (60); (61); (62); Substitute the formula combination corresponding to formula (59)-formula (62) into formula (49)-formula (51), when Using the superposition principle (when the conditions are met), the average excess porosity pressure of the gravel shell, the average excess porosity pressure of the composite strata, and the average degree of consolidation under slope load can be derived as formulas (63), (64), and (65), respectively: (63); (64); (65); When applying the method for determining the degree of consolidation of composite piles for reinforcing soft soil foundations that considers the anisotropy of soft soil provided by this invention, it is not necessary to consider... Figure 1 The steps shown are executed in sequence. The specific execution order of each step can be determined as needed, and this invention does not impose any restrictions on it.

[0085] In one exemplary embodiment, this section verifies the effectiveness of the current model by comparing it with existing composite foundation consolidation models. Since analytical models of anisotropic behavior in soft soil are limited, the anisotropic consolidation model proposed in this invention is simplified to an isotropic form for ease of comparison. This simplification can be achieved by setting the parameter controlling the anisotropic evolution to zero. Under this condition, the simplified model is completely consistent with the analytical model.

[0086] The parameter values ​​are: , , , , , , , , , , , .

[0087] In addition, a dimensionless horizontal time factor is used to simplify the calculation as formula (66): (66); in, A dimensionless horizontal time factor. The initial horizontal consolidation coefficient, It is the square of the diameter of the unit cell.

[0088] Figure 6 The diagram shows a comparison between the average degree of consolidation predicted by this invention and the results of several established analytical models, including research group A (2002), research group B (2013), research group C (2016), research group D (2022), and research group E (2024). Figure 6 As shown, the unit of the horizontal time factor is [missing information]. Among all models, the model proposed by research group B (2013) predicts the lowest average degree of consolidation. This result can be attributed to the free strain assumption used in this model, which tends to yield a more conservative estimate of consolidation progress. In contrast, other models, built on the isostrain assumption, typically produce higher predicted degrees of consolidation. The model proposed by research group C (2016) predicts the highest average degree of consolidation. The predictions of research group A (2002) are in high agreement with those of research group C (2016). It is worth noting that both models only consider radial drainage and ignore vertical flow, but they differ in methodology: research group A (2002) provides a closed-form analytical solution, while research group C (2016) uses a numerical method.

[0089] The current model's predictions fall between the lower limit given by research group B (2013) and the upper limit proposed by Deb and research group C, and are in high agreement with the consolidation curve proposed by research group D (2022). Both the current model and the study by research group D (2022) consider the combined effects of vertical and radial flows, providing a more comprehensive characterization of the consolidation process. However, the model of research group D (2022) did not include nonlinear consolidation effects, which this study has incorporated. When the anisotropic evolution parameter is set to zero, the predicted consolidation curve of research group E (2024) is completely consistent with the current model. This is expected, as the simplified deconstruction of the proposed model is mathematically equivalent to the isotropic model proposed by research group E (2024).

[0090] This invention comprehensively explores the influence of key anisotropic parameters on the nonlinear consolidation behavior of improved soil through parametric studies. It should be noted that the parameters used in this invention are primarily based on the characteristics of clay from a specific location. The parameter settings for subsequent studies are as follows: , , , , , , , , , , Parameters were ignored to maintain consistency with the model validation phase. The clay in this area is known for its significant anisotropic behavior, and its mineral composition mainly includes illite, chlorite, and kaolinite. Undisturbed samples used in the triaxial tests were collected from depths of 3.5–4.7 meters. These are the optimal values ​​used by researchers in their 2003 study of S-CLAY1. Initial rotational hardening parameters. Normal consolidation value Sure.

[0091] Figure 7 The curves showing the average degree of consolidation as a function of time under different critical friction angles provided by this invention. Figure 7 The curves in the middle represent the relationship between time and average degree of consolidation when the critical friction angle is different. Based on the Jaky formula and the Mohr-Coulomb criterion, the critical friction angle... With static earth pressure coefficient and the stress ratio under critical conditions Related. Furthermore, the critical friction angle It is also related to rotational hardening parameters and volumetric compressibility factors. Therefore, changes in these parameters can affect the consolidation process of composite foundations. Specifically, such as... Figure 7 As shown, the average degree of consolidation is lowest when the critical friction angle is 1E⁻⁴, and highest when the critical friction angle is 10°. The consolidation rate of the composite foundation increases with the increase of the critical friction angle.

[0092] Figure 8 This is a schematic diagram showing the variation curves of the main parameters of the present invention with the friction angle at the critical state. Figure 8 Figure (a) shows the curve of stress ratio as a function of the friction angle at the critical state. Figure 8 Figure (b) shows the curves of rotational hardening parameters as a function of the critical friction angle. Figure 8 Figure (c) shows the curve of the average volume compressibility factor as a function of the critical friction angle. Figure 8 The influence of the critical friction angle on the stress ratio, rotational hardening parameters, and volumetric compressibility coefficient between the conditional and critical states is demonstrated. Figure 8 Figure (a) and Figure 8 As shown in Figure (b), the stress ratio under the conditional state, the stress ratio under the critical state, and the rotational hardening parameter all vary with the friction angle under the critical state. The rate of increase of the rotational hardening parameter eventually exceeds that of the initial parameter. M When the initial parameters are set, the final rotational hardening parameters are lower than the initial values. However, as... The increase eventually exceeds the initial value. For example... Figure 8 As shown in Figure (c), the average volumetric compressibility factor changes with the critical friction angle. Increased and amplified. These results indicate that a higher critical state friction angle corresponds to a harder surrounding rock and soil, thereby accelerating the consolidation process of the composite foundation.

[0093] Figure 9 This invention provides a depth-based distribution map of porosity overpressure in composite formations under different critical friction angles. Figure 9 The influence of the critical friction angle on the depth distribution of average porosity overpressure in composite formations is shown, such as... Figure 9 As shown, the unit of depth is m The unit of average excess pore water pressure is In the early stages, the excess pore pressure distribution curves are quite similar in both cases. Because the upper boundary of the composite stratum is permeable, water can drain freely; while the lower boundary is impermeable, hindering the drainage process. Therefore, the excess pore pressure near the surface dissipates faster in both cases. The dissipation rate near the surface is significantly faster than in the case with the lower boundary. In both cases, most of the pore pressure has dissipated to the vicinity of the surface. Specifically, the permeable pore pressure drops to approximately 1 kPa and 1 kPa, respectively. The pore pressure dissipates significantly faster in the middle region of the composite stratum than in the bottom boundary region, while the values ​​near the bottom boundary remain essentially consistent in both cases. In both cases, the dissipation process of excess pore pressure near the surface is essentially complete, and the value approaches zero. However, with increasing burial depth, the value... u The pressure begins to rise, and the difference between the pressure and the average excess pore pressure is significantly amplified. At the bottom of the composite formation, the dissipation of the average excess pore pressure lags significantly behind, highlighting the important influence of the critical friction angle on deep consolidation behavior.

[0094] Figure 10 The present invention provides curves showing the variation of average degree of consolidation with time under different conditions. Figure 10 The parameters controlling the average degree of consolidation of the composite foundation are shown. The effect on the average consolidation rate. For example... Figure 10 As shown, with Increasing the parameter value significantly slows down the consolidation process, leading to a decrease in the average degree of consolidation at any given time. This parameter plays a crucial role in regulating the rate of consolidation and the average dissipation of pore water pressure; that is, the lower the value, the greater the overall stiffness and the faster the overall consolidation rate of the composite foundation. As the parameter value increases... The increase in ...

[0095] Figure 11 This is a schematic diagram of the average volume compressibility factor as a function of angle, as provided by the present invention. Figure 11 As shown, when the parameter As the value changes from 0 to 180, the average volumetric compressibility factor decreases from 5.68 to 2.99. This indicates that the higher the parameter value, the greater the volumetric compressibility of the surrounding soil, thereby effectively reducing the dissipation rate of pore water pressure.

[0096] Figure 12 This is a schematic diagram illustrating the distribution of excess pore pressure along depth in composite formations under different conditions, as provided by the present invention. Figure 12 As shown, the unit of depth is m The unit of average excess pore water pressure is The dissipation rate of average excess pore water pressure also decreases significantly with increasing parameter value. This demonstrates that this parameter plays a crucial role in regulating the consolidation process rate and the dissipation of average excess pore water pressure—the lower the value, the greater the overall stiffness, and the faster the overall consolidation rate of the composite foundation. Figure 12 As shown, the dissipation rate of average excess pore water pressure also varies with parameter values. The increase led to a significant decrease.

[0097] Figure 13 The graphs showing the variation of average degree of consolidation with time under different conditions provided by this invention illustrate the parameters. The influence of this parameter determines the relative contribution of plastic shear strain and plastic volumetric strain to the total objective value of rotational hardening variables, thus affecting the average consolidation degree of the composite formation. When When the coefficient of rotational hardening is 0, the change in rotational hardening parameters is entirely dominated by plastic volumetric strain. As the coefficient of rotational hardening increases, the influence of plastic shear strain on the evolution of parameters gradually becomes more prominent.

[0098] Figure 14 This is a schematic diagram showing the changes in the main parameters provided by the present invention. Based on the study of formula (25), It has a direct impact on the final values ​​of rotational hardening parameters. Specifically, it has a negative impact on the values: that is, on the final values. The larger, The lower the corresponding value, the more likely the inclined yield surface will tend towards a more isotropic shape when the value is large. Figure 14 As shown in Figure (a), with As the value increases, and The differences between them will also widen. Correspondingly, such as Figure 14 As shown in Figure (b), the average volume compressibility factor will vary with... The value increases and then decreases. Therefore, as... Figure 13 As shown, as the numerical value increases, the consolidation process of the composite soil slows down due to the reduced contribution of plastic volumetric strain to rotational hardening and the increased compressibility.

[0099] Figure 15This is a schematic diagram illustrating the distribution of excess pore pressure along depth in composite formations under different conditions, as provided by the present invention. Figure 15 As shown, the unit of depth is m The unit of average excess pore water pressure is The dissipation rate of the average excess pore pressure will also increase with... The value increases but decreases significantly.

[0100] The above describes a method for determining the degree of consolidation of composite piles considering the anisotropy of soft soil, provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding device for determining the degree of consolidation of composite piles considering the anisotropy of soft soil, such as... Figure 16 As shown.

[0101] Figure 16 A schematic diagram of a device for determining the degree of consolidation of a composite pile for reinforcing a soft soil foundation, considering the anisotropy of soft soil, provided by the present invention, includes: The first acquisition module 1601 is used to acquire the yield function that combines the size hardening law and the rotational hardening law; the yield surface in the yield function is represented by an inclined ellipse to represent the anisotropic behavior of the soft soil around the composite pile; the size hardening law changes the size of the yield surface by adjusting the hardening parameters; the rotational hardening law is used to describe the rotational characteristics of the yield surface.

[0102] The second acquisition module 1602 is used to acquire the calculation formula describing the nonlinear seepage behavior of soft soil around composite piles; the calculation formula for nonlinear seepage behavior is used to represent the nonlinear relationship between void ratio and permeability coefficient.

[0103] Module 1603 is used to combine the yield function, the calculation formula describing nonlinear seepage behavior, and the calculation formula for the average degree of consolidation to solve the average degree of consolidation of composite pile-reinforced soft soil foundations under different loading methods. The calculation formula for the average degree of consolidation is constructed based on the effects of anisotropic behavior, nonlinear seepage behavior, and disturbance on the horizontal permeability of the coating strip.

[0104] Specific limitations regarding the device for determining the degree of consolidation of composite piles for soft soil foundations considering anisotropy can be found in the limitations of the method for determining the degree of consolidation of composite piles for soft soil foundations considering anisotropy, and will not be repeated here. Each module in the aforementioned device for determining the degree of consolidation of composite piles for soft soil foundations considering anisotropy can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0105] The present invention also provides a computer-readable storage medium storing a computer program that can be used to execute the above-described... Figure 1 A method for determining the degree of consolidation of composite piles for reinforcing soft soil foundations, taking into account the anisotropy of soft soil, is provided.

[0106] The present invention also provides Figure 17 The schematic diagram of the computer device shown is as follows: Figure 17 As shown, at the hardware level, this computer device includes a processor, internal bus, network interface, memory, and non-volatile memory, and may also include other hardware required for business operations. The processor reads the corresponding computer program from the non-volatile memory into memory and then executes it to achieve the above. Figure 1 A method for determining the degree of consolidation of composite piles for reinforcing soft soil foundations, taking into account the anisotropy of soft soil, is provided.

[0107] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided by this invention can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0108] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this invention.

Claims

1. A method for determining the degree of consolidation of composite piles for soft soil foundation reinforcement considering the anisotropy of soft soil, characterized in that, include: A yield function combining dimensional hardening and rotational hardening laws is obtained; the yield surface in the yield function is represented by an inclined ellipse to depict the anisotropic behavior of the soft soil around the composite pile; the dimensional hardening law changes the size of the yield surface by adjusting the hardening parameters; the rotational hardening law is used to describe the rotational characteristics of the yield surface. Obtain the calculation formula describing the nonlinear seepage behavior of soft soil around composite piles; the calculation formula for nonlinear seepage behavior is used to express the nonlinear relationship between void ratio and permeability coefficient; The yield function, the calculation formula describing nonlinear seepage behavior, and the calculation formula for the average degree of consolidation are combined to solve the average degree of consolidation of composite pile-reinforced soft soil foundations under different loading methods. The formula for calculating the average degree of consolidation is based on the anisotropic behavior, the nonlinear permeation behavior, and the influence of disturbances on the horizontal permeability of the coating strip.

2. The method as described in claim 1, characterized in that, The formula corresponding to the dimension hardening law is: ； in, To determine the hardening parameters for the yield curve size, v For specific volume, The compression index, For total volumetric strain, for The differential; The formula corresponding to the rotational hardening law is: ； in, To control the rotational hardening parameters of the yield curve inclination angle, and It is control Two positive definite constants, For plastic volumetric strain, The range of values ​​for is [ , ], for The differential; The yield function is: ； in, f Let be the yield function. g Let be the plastic potential function. It is a deviatoric stress. M The critical stress ratio. For the average effective stress, To determine the hardening parameters for the yield curve size, Rotational hardening parameters are used to control the tilt angle of the yield curve.

3. The method as described in claim 1, characterized in that, The calculation formula describing the nonlinear seepage behavior of soft soil around composite piles is as follows: ； in, Given the current porosity, The initial void ratio, The initial vertical permeability coefficient of the soft soil surrounding the composite pile is given. Let be the initial horizontal permeability coefficient of the soft soil surrounding the composite pile. The horizontal permeability coefficient of undisturbed soil. The vertical permeability coefficient of the soft soil surrounding the composite pile is given. Let be the initial vertical permeability coefficient of the soft soil surrounding the composite pile. denoted as the initial horizontal permeability coefficient of the soft soil surrounding the composite pile.

4. The method as described in claim 1, characterized in that, The composite pile reinforcement of soft soil foundation includes a rigid core, a gravel shell, and soft soil surrounding the composite pile; the formula for calculating the average degree of consolidation is: ； in, The average degree of consolidation for composite pile reinforcement of soft soil foundations, For depth z Time t Variable additional loads, H This represents the total thickness of the soft soil surrounding the composite pile. , , , , , , , , = , , For depth z The final additional load at the location, The average volume compressibility factor during the consolidation process. Let be the area of ​​the gravel shell. This represents the area of ​​the soft soil surrounding the composite pile. The area of ​​a unit cell. , The density of water, , The initial average effective stress of the soft soil surrounding the composite pile is given. , Let be the slope of the canonical consolidation line in the plane. The final volume compression factor, The initial vertical permeability index is the soft soil surrounding the composite pile. Let be the permeability coefficient of the gravel shell. It is the square of the unit cell radius. Let be the initial vertical permeability coefficient of the soft soil surrounding the composite pile. Let be the initial horizontal permeability coefficient of the soft soil surrounding the composite pile. The initial average effective stress of the soft soil surrounding the composite pile is given. The initial horizontal permeability index is the soft soil surrounding the composite pile. To determine the effect of disturbance on the horizontal penetration rate of the coating strip. , It is the initial volume compressibility factor during the consolidation process of soft soil around composite piles. The average volumetric compressibility factor during the consolidation of soft soil around composite piles. , = , Let be the area of ​​the rigid core. , The initial volume compressibility index, The volumetric compression index of a rigid core. , The volumetric compressibility index of the gravel shell is . To add the final load.

5. The method as described in claim 4, characterized in that, The average volume compressibility factor is: ； in, The average volume compressibility factor. v For specific volume, The compression index, The inflation index, Critical stress ratio Rotational hardening parameters are used to control the slope angle of the yield curve. for initial value, and To control Two positive definite constants, , This is the coefficient of earth pressure at rest.

6. The method as described in claim 4, characterized in that, The formula for calculating the effect of the disturbance on the horizontal penetration rate of the coating strip is as follows: ； in, , , , , The permeability coefficient of the coating area varies with the radius. A changing function, The radius of the composite pile, The radius of the unit cell, r Let be the radius.

7. The method as described in claim 1, characterized in that, The different loading methods include instantaneous load and slope loading; the method of simultaneously solving the formulas for yield function, nonlinear seepage behavior, and average degree of consolidation to determine the average degree of consolidation of composite pile-reinforced soft soil foundations under different loading methods specifically includes: The equations corresponding to instantaneous load, the calculation formula describing nonlinear seepage behavior, and the calculation formula for average degree of consolidation are combined to solve for the average degree of consolidation of composite pile-reinforced soft soil foundation under instantaneous load. By combining the equations corresponding to slope loading, the calculation formula describing nonlinear seepage behavior, and the calculation formula for average degree of consolidation, the average degree of consolidation of the composite pile-reinforced soft soil foundation under slope loading is solved.

8. The method as described in claim 7, characterized in that, The equation combination corresponding to the instantaneous load is: ； ； ； ； in, For depth z Time t Variable additional loads, This represents the total stress at the top boundary of the composite pile-reinforced soft soil foundation. These represent the total stress at the bottom boundary of the composite pile-reinforced soft soil foundation. H This represents the total thickness of the soft soil surrounding the composite pile. , , , , ; The equation combination corresponding to the slope load is: ； ； ； ； in, This represents the starting time of the slope loading.

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