Numerical simulation method and system suitable for power piling in cohesionless soil

Abstract

The invention relates to the technical field of geotechnical mechanics, in particular to a numerical simulation method and system suitable for power piling in cohesionless soil, and the method comprises the steps: obtaining a power piling generalization model and a cohesionless soil sample of a target research area; determining sub-plastic model parameters of the cohesionless soil and linear elasticity model parameters of the pile, and determining a linear elasticity model of the pile on the basis of the sub-plastic model parameters of the cohesionless soil and the linear elasticity model parameters of the pile; a pre-established numerical model is utilized to call a preset VUMAT subprogram to conduct soil body behavior simulation on the large deformation of the soil body and the dynamic change of the pore water pressure in the dynamic piling process, a simulated piling result is obtained, and the preset VUMAT subprogram is obtained through writing of an improved CEL method. Therefore, the problems of complex model, numerous parameters and difficult solution in the solution process in the related technology are solved, and the model complexity and the solution difficulty are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of dynamic piling, and in particular to a numerical simulation method and system suitable for dynamic piling in non-cohesive soil. Background Art

[0002] Dynamic piling is a construction technology that uses mechanical dynamic loads (such as vibration or impact) to drive prefabricated piles into the ground. The principle is to use dynamic loads to destroy the soil structure around the pile, reduce the resistance between the pile and the soil, and thus allow the pile to sink smoothly. This technology has the advantages of wide application range, high construction efficiency, and low environmental pollution, and is widely used in construction projects. In the past, dynamic piling was mainly used in soft clay layers because these soil layers have relatively small resistance and low requirements for mechanical properties. In recent years, with the upgrading of piling equipment, the application of this technology in harder sandy soil layers has developed rapidly. Sandy soil is a typical non-cohesive granular material with weak cohesion between particles, strong permeability and low compressibility. It is easy to liquefy when subjected to strong dynamic loads in a saturated state, and its strength drops sharply. However, the theoretical model and calculation method of dynamic piling developed for soft clay soil show significant limitations when applied to non-cohesive soil, such as the inability to fully consider the effect of soil particle rearrangement on density and permeability, and the difficulty in simulating the process of pore water pressure accumulation and dissipation. Therefore, there is an urgent need for a new method that can be used to deeply study and analyze the pile-soil interaction mechanism and the comprehensive influence of various parameters of dynamic piling in cohesionless soil.

[0003] In the related technologies, it is difficult to construct an accurate and solvable mathematical model to solve the key state variables such as stress, strain, pore water pressure of cohesionless soil using traditional analytical methods because of the problems related to dynamic piling. Therefore, numerical methods are widely used in solving the problems, among which the finite element method has become the most commonly used method with its mature calculation method and rich software resources to solve the problem that the cohesion between particles of the hard sand layer is weak, the permeability is strong and the compressibility is low, and it is easy to liquefy when subjected to strong dynamic loads in a saturated state, resulting in a sharp drop in strength.

[0004] However, when using the finite element method to model and analyze the process of dynamic pile driving in cohesionless soil, there are some difficulties that need to be solved urgently: (1) The elastoplastic model is the mainstream constitutive model of rock and soil today. Most of the rock and soil material models provided in commercial finite element software are based on the elastoplastic theory, such as the Mohr-Columb model, the Cam-Clay model, the Modified Cam-Clay model, the Drucker-Prage model, etc. There are some shortcomings when applying the elastoplastic model to cohesionless soil. For example, the elastoplastic theory decomposes the deformation into elastic and plastic parts, and assumes that there is a yield surface. When the stress state is on the yield surface, the material reaches its yield point and begins to transform into plastic deformation. However, under deviatoric stress loading conditions, cohesionless soil usually does not show a typical yield point, and it is difficult to define its elastic deformation area; during the unloading process, its deformation is not completely reversible. In addition, the elastoplastic theory only uses the plastic volume strain as the hardening parameter to determine the plastic strain, and cannot consider the volume expansion and softening characteristics caused by shear. Moreover, the elastoplastic model is generally based on statics theory, ignoring the loading and unloading process and the motion state of the soil during the construction stage, and directly solving the failure state of the soil through static limit equilibrium analysis. Therefore, there are certain limitations when using the elastoplastic model embedded in commercial finite element software to describe the mechanical response of non-cohesive soil during dynamic pile driving. (2) In the finite element method, the soil around the pile will undergo large displacements during the process of pile driving into the soil, resulting in large nonlinear strains, which is a typical large deformation problem of the soil. When using the traditional finite element method to simulate this process, it is easy to cause mesh distortion and distortion, resulting in non-convergence of the calculation. The main reasons are as follows: First, the finite element method is based on the continuous medium assumption, which assumes that material particles are continuous and void-free in space, and always maintain the shape of a continuum during deformation. Therefore, the grid unit cannot be broken, and it is difficult to simulate the actual situation of piles (especially flat-end piles) being driven into the soil; second, the material movement in the finite element method is based on the Lagrangian description, and the nodes of the grid unit (Lagrangian unit) are bound to the material. When the material undergoes a large deformation, it is easy to cause grid distortion and distortion, resulting in calculation termination. (3) The coupled Euler-Lagrangian (CEL) method was introduced into the large deformation analysis of geotechnical engineering. This method simulates small deformation materials (such as piles) through Lagrangian units and large deformation materials (such as soil) through Euler units, so that the motion domains based on Lagrangian description and Euler description can coexist and interact in a finite element model. The CEL method can effectively simulate the static pressure process of piles and solve the problems of grid quality and convergence caused by large deformation of soil. However, the dynamic piling process is more complicated. Under strong dynamic loads, non-cohesive soils undergo liquefaction, which involves the rearrangement and displacement of soil particles and dynamic changes in pore water pressure.The Euler unit in the CEL method is essentially a fluid unit, which makes it difficult to simulate the flow of pore fluid in solid particles and the interaction between the two, making it impossible to effectively perform water-mechanical coupling analysis, which needs to be solved urgently. Summary of the invention

[0005] The present invention provides a numerical simulation method and system suitable for dynamic piling in cohesionless soil, so as to solve the problems of complex model, numerous parameters and difficult solution in the solution process of related technologies, and reduce the complexity of the model and the difficulty of solution.

[0006] The first aspect of the present invention provides a numerical simulation method suitable for dynamic piling in cohesionless soil, wherein the method comprises: obtaining a generalized model of dynamic piling and cohesionless soil samples in a target study area; determining the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, and based on the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, using a pre-established numerical model to call a preset VUMAT subroutine to simulate the soil behavior of large deformation of the soil and the dynamic changes of pore water pressure during the dynamic piling process, and obtain simulated piling results, wherein the preset VUMAT subroutine is written by an improved CEL method.

[0007] Furthermore, in some embodiments, after obtaining the simulated piling result, it also includes: acquiring piling monitoring data of the target study area; and verifying the simulated piling result based on the piling monitoring data, so as to analyze the accuracy of the numerical model according to the verification result.

[0008] Furthermore, in some embodiments, obtaining a generalized model of dynamic piling in the target study area includes: obtaining site stratigraphic conditions, groundwater conditions and the occurrence state of cohesionless soil in the target study area, and obtaining geological condition analysis results based on the site stratigraphic conditions, the groundwater conditions and the occurrence state of the cohesionless soil; determining pile foundation design parameters based on the geological condition analysis results, wherein the pile foundation design parameters include pile size, material properties, piling equipment and loading parameters; obtaining piling monitoring data of the target study area, and obtaining the generalized model of dynamic piling based on the geological condition analysis results, the pile foundation design parameters and the piling monitoring data.

[0009] Furthermore, in some embodiments, based on the hypoplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, the large deformation of the soil and the dynamic change of the pore water pressure in the process of dynamic piling are simulated by using a preset VUMAT subroutine to obtain the simulation results of the soil behavior, including: based on the hypoplastic model parameters of the cohesionless soil, a Niemunis-Herle hypoplastic model is constructed, and the VUMAT subroutine of the Niemunis-Herle hypoplastic model is embedded in the preset ABAQUS software to obtain the simulation results of the mechanical behavior of the cohesionless soil; based on the preset Darcy's law, a preset pore fluid mass balance equation is rewritten, and the temperature in the preset thermal energy balance equation is replaced according to the excess pore fluid pressure of the rewritten pore fluid mass balance equation, and based on the replacement The improved CEL method is determined by combining the analysis results with the heat balance equation after the change, simulating the diffusion of pore fluid in the soil skeleton through the heat conduction transfer process in the thermal-displacement coupling analysis program and performing related stress analysis, wherein the preset Darcy's law is used to describe the flow of pore fluid between the soil skeletons, and the preset heat balance equation is set in the thermal-displacement coupling analysis program; the preset VUMAT subroutine is determined according to the improved CEL method, and based on the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, the preset VUMAT subroutine is called by using the pre-established numerical model to simulate the soil behavior of the large deformation of the soil and the dynamic change of the pore water pressure during the dynamic piling process, and the simulated piling result is obtained in combination with the mechanical behavior simulation result of the cohesionless soil.

[0010] Furthermore, in some embodiments, before using the pre-established numerical model to call the preset VUMAT subroutine to simulate the soil behavior results of the large deformation of the soil and the dynamic changes of the pore water pressure during the dynamic piling process, it also includes: based on the generalized model of dynamic piling, three-dimensional geometric modeling of the piles and the soil is performed to obtain the modeled piles and the modeled soil; based on the preset Lagrangian unit and the preset Euler unit, the improved CEL method is used to mesh the modeled piles and the modeled soil to obtain meshing results; boundary conditions and pile-soil contact characteristics are determined according to the soil behavior simulation results, and the pre-established numerical model is constructed based on the meshing results, the boundary conditions and the pile-soil contact characteristics.

[0011] The numerical simulation method for dynamic piling in cohesionless soil provided by the embodiment of the present invention can accurately simulate the process of pile driving into soil under dynamic load (such as vibration or impact), the mechanical behavior of cohesionless soil, and the dynamic change of pore water pressure, etc., and realize the modeling and analysis of the dynamic piling process in cohesionless soil. The problems of complex model, numerous parameters, and difficult solution in the solution process of related technologies are solved, and the model complexity and solution difficulty are reduced.

[0012] The second aspect of the present invention provides a numerical simulation system suitable for dynamic piling in cohesionless soil, wherein the device includes: an acquisition module, used to obtain a generalized model of dynamic piling and a cohesionless soil sample in a target study area; a data processing module, used to determine the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, and based on the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, use a pre-established numerical model to call a preset VUMAT subroutine to simulate the soil behavior of large deformation of the soil and the dynamic changes of pore water pressure during dynamic piling, and obtain simulated piling results, wherein the preset VUMAT subroutine is written by an improved CEL method.

[0013] Furthermore, in some embodiments, after obtaining the simulated piling results, the data processing module is also used to: obtain the piling monitoring data of the target study area; and verify the simulated piling results based on the piling monitoring data, so as to perform accuracy analysis on the numerical model according to the verification results.

[0014] Furthermore, in some embodiments, the acquisition module is specifically used to: obtain the site stratigraphic conditions, groundwater conditions and the occurrence state of cohesionless soil in the target study area, and obtain geological condition analysis results based on the site stratigraphic conditions, the groundwater conditions and the occurrence state of the cohesionless soil; determine pile foundation design parameters based on the geological condition analysis results, wherein the pile foundation design parameters include pile size, material properties, pile driving equipment and loading parameters; obtain the pile driving monitoring data of the target study area, and obtain the dynamic pile driving generalization model based on the geological condition analysis results, the pile foundation design parameters and the pile driving monitoring data.

[0015] Furthermore, in some embodiments, the data processing module is specifically used to: construct a Niemunis-Herle hypoplastic model based on the hypoplastic model parameters of the cohesionless soil, and embed the VUMAT subroutine of the Niemunis-Herle hypoplastic model into the preset ABAQUS software to obtain the mechanical behavior simulation results of the cohesionless soil; rewrite the preset pore fluid mass balance equation based on the preset Darcy's law, and replace the temperature in the preset thermal energy balance equation according to the super pore fluid pressure of the rewritten pore fluid mass balance equation, and based on the replaced thermal energy balance equation, simulate the pore fluid in the heat conduction transfer process in the thermal-displacement coupling analysis program. The diffusion in the soil skeleton is analyzed and related stress analysis is performed to determine the improved CEL method in combination with the analysis results, wherein the preset Darcy's law is used to describe the flow of pore fluid between the soil skeletons, and the preset thermal energy balance equation is set in the thermal-displacement coupling analysis program; the preset VUMAT subroutine is determined according to the improved CEL method, and based on the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, the preset VUMAT subroutine is called by using a pre-established numerical model to simulate the soil behavior of the large deformation of the soil and the dynamic change of the pore water pressure during the dynamic piling process, and the simulated piling result is obtained in combination with the mechanical behavior simulation result of the cohesionless soil.

[0016] Furthermore, in some embodiments, before using the pre-established numerical model to call the preset VUMAT subroutine to simulate the soil behavior results of the large deformation of the soil and the dynamic changes of the pore water pressure during the dynamic piling process, the data processing module is also used to: based on the generalized model of dynamic piling, perform three-dimensional geometric modeling of the piles and the soil to obtain the modeled piles and the modeled soil; based on the preset Lagrangian unit and the preset Euler unit, use the improved CEL method to mesh the modeled piles and the modeled soil to obtain meshing results; determine the boundary conditions and the pile-soil contact characteristics, and construct the pre-established numerical model based on the meshing results, the boundary conditions and the pile-soil contact characteristics.

[0017] The numerical simulation system for dynamic piling in cohesionless soil provided by the embodiment of the present invention can accurately simulate the process of pile driving into soil under dynamic load (such as vibration or impact), the mechanical behavior of cohesionless soil, and the dynamic change of pore water pressure, etc., and realize the modeling and analysis of the dynamic piling process in cohesionless soil. The problems of complex model, numerous parameters, and difficult solution in the solution process of related technologies are solved, and the model complexity and solution difficulty are reduced.

[0018] Therefore, the numerical simulation method for dynamic piling in cohesive-free soil according to the embodiment of the present invention has the following beneficial effects: (1) The embodiment of the present invention embeds the Niemunis-Herle hypoplastic model developed for cohesionless granular materials into the ABAQUS software, which can accurately simulate the particle rearrangement, displacement, and mechanical properties such as inelasticity, dilatancy, softening and liquefaction of cohesionless soil under dynamic loads, overcomes the limitations of the elastoplastic model, and improves the accuracy and reliability of the simulation results.

[0019] (2) The embodiment of the present invention enables the Euler unit in the CEL method to effectively simulate the diffusion of pore fluid in the soil skeleton and perform related stress analysis, successfully solving the problem that the Euler unit is difficult to characterize the accumulation and dissipation of pore water pressure when simulating large deformation soils, thereby realizing water-mechanical coupling analysis.

[0020] (3) The embodiment of the present invention improves the CEL method and embeds it into ABAQUS software, thereby solving the shortcomings of the Euler unit in simulating the diffusion of pore fluid in the soil skeleton and related stress analysis. It can accurately reflect the accumulation and dissipation of pore water pressure in large deformation soil during dynamic piling, and improves the applicability of the CEL method in large deformation analysis of geotechnical engineering.

[0021] (4) The embodiments of the present invention solve the limitations of the elastoplastic model, the mesh problem caused by large soil deformation, and the problem that the CEL method is not applicable to water-mechanical coupling analysis. It can effectively simulate the physical phenomena in the dynamic pile driving process and fill the gap in numerical technology in the field of dynamic pile driving.

[0022] (5) The embodiments of the present invention can accurately simulate the process of pile driving into soil under dynamic load, the mechanical behavior of cohesionless soil, and the dynamic changes of pore water pressure, etc., and effectively solve the problems of traditional analytical methods in solving problems related to dynamic pile driving, such as complex models, numerous parameters, and difficulty in solving.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 A flow chart of a numerical simulation method for dynamic piling in cohesionless soil provided according to an embodiment of the present invention; Figure 2 A schematic diagram of a technical route for secondary development based on a VUMAT subroutine provided according to a specific embodiment of the present invention; Figure 3A flow chart of a numerical simulation method provided according to a specific implementation of the present invention; Figure 4 The present invention is a block diagram of a numerical simulation system for dynamic piling in cohesionless soil provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0026] The numerical simulation method and system for dynamic pile driving in cohesionless soil according to the embodiment of the present invention are described below with reference to the accompanying drawings. In view of the problems of complex models, numerous parameters, and difficulty in solving the problems mentioned in the above background technology in the process of solving the related technology, the present invention provides a numerical simulation method for dynamic pile driving in cohesionless soil, which can accurately simulate the process of pile driving into soil under the action of dynamic loads (such as vibration or impact), the mechanical behavior of cohesionless soil, and the dynamic changes of pore water pressure, etc., realize the modeling and analysis of the dynamic pile driving process in cohesionless soil, solve the problems of complex models, numerous parameters, and difficulty in solving the problems in the process of solving the related technology, fill the relevant gaps in numerical technology in the field of dynamic pile driving, and provide new technical means for the design and construction of dynamic pile driving projects.

[0027] Specifically, Figure 1 The present invention is a flowchart of a numerical simulation method for dynamic piling in cohesive-free soil provided in an embodiment of the present invention.

[0028] like Figure 1 As shown, the numerical simulation method for dynamic piling in cohesionless soil includes the following steps: In step S101, a generalized dynamic piling model and cohesionless soil samples of a target research area are obtained.

[0029] Furthermore, in some embodiments, obtaining a generalized model of dynamic piling in the target study area includes: obtaining site stratigraphic conditions, groundwater conditions and the occurrence state of cohesionless soil in the target study area, and obtaining geological condition analysis results based on the site stratigraphic conditions, groundwater conditions and the occurrence state of cohesionless soil; determining pile foundation design parameters based on the geological condition analysis results, wherein the pile foundation design parameters include pile size, material properties, piling equipment and loading parameters; obtaining piling monitoring data in the target study area, and obtaining a generalized model of dynamic piling based on the geological condition analysis results, pile foundation design parameters and piling monitoring data.

[0030] Among them, the site stratigraphic conditions of the target study area include the types and thickness of each stratum, the groundwater conditions include the types and burial depths of each aquifer, and the occurrence state of cohesionless soil includes density and saturation. In addition, the pile size includes length and cross-sectional size, the material properties include density, elastic modulus and Poisson's ratio, etc., the piling equipment can be a vibrating hammer or an impact hammer, and the loading parameters include action frequency and load peak. The piling monitoring data include penetration depth and pore water pressure, etc. Comprehensively considering the influence of various factors, a dynamic piling generalization model is carried out.

[0031] In step S102, the subplastic model parameters of cohesionless soil and the linear elastic model parameters of piles are determined, and based on the subplastic model parameters of cohesionless soil and the linear elastic model parameters of piles, the preset VUMAT subroutine is called by the pre-established numerical model to simulate the soil behavior of large deformation of soil and dynamic changes of pore water pressure during dynamic piling, so as to obtain simulated piling results, wherein the preset VUMAT subroutine is written by the improved CEL method.

[0032] Among them, the determination of material model parameters can be obtained through soil sample collection and testing and construction data consultation. Specifically, soil sample collection and testing can take cohesiveless soil samples from the study area, carry out indoor geotechnical tests, and determine the subplastic model parameters of cohesiveless soil, including: density ρ, critical friction angle φ c , particle hardness h s , index n, upper limit porosity ratio e under zero pressure i0 , critical porosity ratio e at zero pressure c0 , the lower limit porosity ratio e under zero pressure d0 , exponents α and β, maximum intergranular strain R, stiffness factor m R and m T , exponential β r and χ. Construction data include density ρ, elastic modulus E s and Poisson's ratio μ.

[0033] Further, Figure 2 A schematic diagram of a technical route for secondary development based on a VUMAT subroutine according to a specific embodiment of the present invention is shown. Figure 2As shown, the simulation is realized through secondary development based on VUMAT subroutines, including the secondary development of Niemunis-Herle hypoplastic model VUMAT, that is, writing the VUMAT subroutine of Niemunis-Herle hypoplastic model, embedding it into ABAQUS software, and simulating the mechanical behavior of cohesionless soil. The CEL method is improved, that is, the CEL method is improved based on the up form of the saturated soil dynamic equation, Darcy's law is used to describe the flow of pore fluid between the soil skeleton, and according to the pore fluid mass balance equation proposed by Zienkiewicz, the temperature of the thermal energy balance equation in the ABAQUS / Explicit thermal-displacement coupling analysis program is replaced by the super-porous fluid pressure in the pore fluid mass balance equation, and the diffusion of pore fluid in the soil skeleton is simulated through the heat conduction transfer process in the thermal-displacement coupling analysis program and the related stress analysis is performed, and the related control equations are modified to determine the constants required for the model. The secondary development of VUMAT with improved CEL method is to write VUMAT subroutine of improved CEL method and embed it into ABAQUS software to simulate the large deformation of soil and dynamic changes of pore water pressure during dynamic piling process.

[0034] It should be noted that ABAQUS is a finite element software with a rich variety of unit types, material models and analysis processes. It can simulate single parts and complex systems in many fields such as solid mechanics and fluid mechanics, support modeling and analysis of multi-physical field coupling, and provide secondary development interfaces to meet the specific needs of users. In addition, during the simulation process, the simulation of pile driving and soil behavior are carried out simultaneously, and pile driving causes changes in soil behavior.

[0035] Furthermore, in some embodiments, before using a pre-established numerical model to call a preset VUMAT subroutine to simulate the soil behavior results of large soil deformation and dynamic changes in pore water pressure during dynamic piling, it also includes: based on a generalized model of dynamic piling, three-dimensional geometric modeling of piles and soil to obtain modeled piles and modeled soil; based on preset Lagrangian units and preset Euler units, using an improved CEL method, meshing the modeled piles and modeled soil to obtain meshing results; determining boundary conditions and pile-soil contact characteristics based on the soil behavior simulation results, and constructing a pre-established numerical model based on the meshing results, boundary conditions and pile-soil contact characteristics.

[0036] Among them, according to the generalized model of dynamic piling, three-dimensional geometric modeling of piles and soil is carried out. The CEL method is adopted, and the piles and soil are meshed using Lagrangian units to simulate piles and Euler units to simulate soil. The boundary conditions affect the prediction of the influence range of dynamic piling, including force and drainage conditions. The pile-soil contact characteristics include appropriate contact models, friction coefficients, etc. According to the generalized model of dynamic piling, the loading mode and analysis steps of the pile are set, including loading form, frequency, force, etc., to simulate the actual dynamic piling construction process, and the above-mentioned VUMAT subroutine is called at each time increment and each integration point.

[0037] Furthermore, in some embodiments, after obtaining the simulated piling results, it also includes: acquiring piling monitoring data of the target study area; and verifying the simulated piling results based on the piling monitoring data, so as to analyze the accuracy of the numerical model according to the verification results.

[0038] Among them, the numerical model can be verified according to the layout of on-site construction monitoring points and monitoring data (footage depth, pore water pressure, etc.) to ensure the accuracy and reliability of the model. And the numerical calculation results can be output as needed, such as soil porosity, excess pore water pressure, effective stress, etc., as well as pile stress, strain, etc.; according to the pile foundation design and construction plan, the values ​​of key parameters are changed to study and analyze the physical phenomena in the dynamic pile driving process and the comprehensive impact of various parameter changes on the dynamic pile driving process.

[0039] In order to enable relevant practitioners in the field to better understand the numerical simulation method for dynamic piling in cohesionless soil according to an embodiment of the present invention, it is described below in conjunction with specific embodiments.

[0040] It should be noted that this embodiment takes the piling construction of Larsen steel sheet piles in a certain project as an example. The site stratum is mainly composed of sandy soil, which belongs to the category of non-cohesive soil. In order to ensure the smooth installation of the steel sheet piles, a vibrating pile driver is used as the main construction equipment.

[0041] Figure 3 A flow chart of a numerical simulation method provided according to a specific implementation of the present invention is shown as follows: Figure 3 As shown, this embodiment includes the following steps: In step S301, the dynamic pile driving model is generalized.

[0042] For example, the embodiments of the present invention can consult the geotechnical engineering investigation report to clarify that the strata in the study area are mainly fine sand, sandy silt and silty clay, wherein the depth of about 0-4 m is a plain fill layer, 4-16 m is a fine sand layer, and 16-20 m is a silty clay layer; within the exploration depth range, the groundwater level is revealed to be about 4.15-16.00 m deep, and the aquifer is a fine sand layer, indicating that the soil layer is in a saturated state; through the standard penetration test, the N value of the fine sand is obtained to be about 30, indicating that the soil layer is in a relatively dense state.

[0043] Furthermore, the embodiment of the present invention can refer to the pile foundation design and construction plan to clarify that the Larsen steel sheet pile has a U-shaped pile shape, a pile length of 12 m, a cross-sectional size of 400 mm in width, 170 mm in height, 15.5 mm in thickness, and an area of ​​96.99 cm²; the linear elastic model parameters of the steel are a density of 7.85 g / cm3, an elastic modulus of 2.06×108 kPa, and a Poisson's ratio of 0.3; the vibrating pile driver used outputs a high-frequency vibration load with a vibration frequency of 47 Hz, an exciting force peak of 580 kN, and a target piling depth of 12 m.

[0044] Furthermore, the embodiment of the present invention can clarify the layout of the on-site pore water pressure gauges by consulting the construction monitoring report: a total of 2 pore water pressure gauges are buried, 15.5 cm away from the pile axis, with burial depths of 3 m and 9 m respectively, and the monitoring data of the pore water pressure gauges and the advancement process of the steel sheet piles (the piling depth and required time at each stage) and the final piling depth (11.5 m) are recorded.

[0045] In step S302, material model parameters are determined.

[0046] Specifically, the embodiment of the present invention can use fine sand samples to carry out indoor geotechnical tests. The maximum porosity ratio is determined by relative density test. e max , minimum porosity ratio e min And relative density D r (60%), further determine the upper limit porosity ratio under zero pressure e i0 , critical porosity ratio at zero pressure e c0 , the lower limit porosity ratio at zero pressure e d0 ( e i0 / e max ≈1.2, e c0 ≈ e max , ed0 ≈ e min ); Determination of critical friction angle by triaxial compression test φ c ,index α ; Determine particle hardness by confined or triaxial compression testing h s and index n; the index is determined by cyclic loading test β r and χ , the value range is 0.2≤ β r <1 and 1< χ ≤10; usually, the index β , maximum intergranular strain R, stiffness factor m R and m T is considered as a constant, where β The value is 1, and the value of R is 1×10 -4 , m R and m T The values ​​are 2 and 5 respectively. The parameters of the hypoplastic model are shown in Table 1.

[0047] Table 1

[0048] In step S303, secondary development is performed based on the VUMAT subroutine.

[0049] Specifically, the embodiment of the present invention obtains a constitutive model of a hypoplastic critical state according to a general form of a hypoplastic model that can consider a deviatoric stress critical state surface:

[0050]

[0051] in, , , .

[0052] Furthermore, considering the change in stiffness of granular materials under small strain conditions, the general form of the Niemunis-Herle hypoplastic model is obtained as follows:

[0053]

[0054] in, ρ is a state variable, when ρ =1:

[0055] When 0< ρ <1 hour:

[0056] in, is the Jaumann stress rate tensor; is the density factor; is the pressure factor; is the upper limit porosity ratio under mean stress; is the critical void ratio under mean stress; is the lower limit void ratio under average stress; D is the strain rate tensor; L and N represent the stress rate components of linear and nonlinear strain rate, respectively; yes The bias part is , ; ψ Stress state related parameters, through and The norm of establishes the relationship; is the stiffness tensor; R is the maximum interparticle strain; is the hypoplastic tensor; is the interparticle strain tensor; yes direction; m R and m T are the stiffness factors when the strain path changes by 180° and 90°, m R > m T >1; It is a weighting factor for smoothing. According to the VUAMT subroutine interface and programming framework structure provided by ABAQUS software, the VUMAT subroutine of Niemunis-Herle hypoplastic model is written. When writing, the state variables are defined strictly according to the interface requirements, and the specified data structure and transfer mechanism are followed to pass the updated stress and state variables to the ABAQUS main program in the correct data format.

[0057] Further, in some embodiments, based on the hypoplastic model parameters of cohesionless soil and the linear elastic model parameters of piles, a preset VUMAT subroutine is used to simulate the large deformation of soil and the dynamic change of pore water pressure during dynamic piling to obtain soil behavior simulation results, including: based on the hypoplastic model parameters of cohesionless soil, a Niemunis-Herle hypoplastic model is constructed, and the VUMAT subroutine of the Niemunis-Herle hypoplastic model is embedded in the preset ABAQUS software to obtain the mechanical behavior simulation results of cohesionless soil; based on the preset Darcy's law, a preset pore fluid mass balance equation is rewritten, and the temperature in the preset thermal energy balance equation is replaced according to the excess pore fluid pressure of the rewritten pore fluid mass balance equation. And based on the replaced thermal energy balance equation, the diffusion of pore fluid in the soil skeleton is simulated through the heat conduction transfer process in the thermal-displacement coupling analysis program and the related stress analysis is carried out, so as to determine the improved CEL method in combination with the analysis results, wherein the preset Darcy's law is used to describe the flow of pore fluid between the soil skeletons, and the preset thermal energy balance equation is set in the thermal-displacement coupling analysis program; the preset VUMAT subroutine is determined according to the improved CEL method, and based on the subplastic model parameters of cohesionless soil and the linear elastic model parameters of piles, the preset VUMAT subroutine is called by using the pre-established numerical model to simulate the soil behavior of large deformation of soil and dynamic changes of pore water pressure in the process of dynamic piling, and the simulated piling results are obtained in combination with the simulation results of the mechanical behavior of cohesionless soil.

[0058] For example, the default Darcy's law is used to describe the flow of pore fluid between the soil skeleton, according to the pore fluid mass balance equation proposed by Zienkiewicz based on the up form saturated soil dynamic equation:

[0059] When the relative acceleration between the pore fluid and the soil skeleton is neglected, the pore fluid mass balance equation is rewritten as:

[0060] Let the pore fluid pressure gradient , pore fluid pressure rate , we can get:

[0061] in, u s is the soil skeleton displacement; p f is the pore fluid pressure; is the pore fluid pressure rate; and are the velocities of the soil skeleton and pore fluid, respectively; and are the accelerations of the soil skeleton and pore fluid, respectively; is the pore fluid volume fraction; is the pore fluid bulk modulus; is the permeability of saturated soil, where is the hydraulic conductivity; is the specific gravity of the pore fluid; is the dynamic viscosity of the pore fluid; b is the gravity; is the pore fluid density.

[0062] Furthermore, the thermal energy balance equation in the ABAQUS / Explicit thermal-displacement coupling analysis program is

[0063] in, ρ is the total density; c is the specific heat; is the rate of temperature change; θ is the temperature; is the thermal conductivity; is the internal heat generation. Substitute the temperature in the heat balance equation θ Replaced by the excess pore fluid pressure in the pore fluid mass balance equation , three matches are identified:

[0064]

[0065]

[0066] Furthermore, the diffusion of pore fluid in the soil skeleton is simulated by the heat conduction transfer process in the thermal-displacement coupling analysis program and the related stress analysis is performed. The related control equations are modified and the constants required for the model are determined as follows: ,

[0067] According to the VUAMT subroutine interface and programming framework structure provided by ABAQUS software, the VUMAT subroutine of the improved CEL method is written. When writing, the state variables are strictly defined according to the interface requirements, and the specified data structure and transfer mechanism are followed to pass the updated stress and state variables to the ABAQUS main program in the correct data format.

[0068] It should be noted that the saturation of fine sand in this specific embodiment is about 0.995, and the saturation density is about 2.2×10 - 3 kg / m 3 , pore water volume fraction is about 0.33, at which point the pore water bulk modulus About 30 MPa; assuming that the pore water density =1, pore water dynamic viscosity 1.006×10 -6 m 2 / s, permeability of fine sand 1×10 -4 Pa, calculation constant c 5.64×10 -6 ,constant 1×10 -4 In the ABAQUS / Explicit thermal-displacement coupling analysis program, the constant c Set to 5.64×10 -6 , the constant Set to 1×10 -4 .

[0069] Furthermore, the embodiment of the present invention can model the actual size of the Larsen steel sheet pile according to the pile foundation design and construction plan; adopt the CEL method, use the Lagrangian unit to simulate the pile body, and the unit type is C3D8R; according to the geotechnical engineering investigation report, the site stratum is generalized into a single fine sand layer; the horizontal distance between the horizontal boundary of the soil body and the pile body is set to 20 times the width of the pile, that is, 8 m, and the vertical height is set to 2 times the length of the pile, that is, 24 m, to eliminate the influence of the finite truncation boundary on the simulation results. The soil body is simulated using the Euler unit, the unit type is EC3D8RT, the units of the pile and the soil body are meshed, and the bottom of the pile body is set to be located on the surface of the soil body.

[0070] Furthermore, the vertical displacement of the bottom of the soil and the horizontal displacement of the side of the soil are restricted to zero; by improving the CEL method, the temperature in the numerical model θ Replaced by excess pore fluid pressure , set the temperature boundary condition with a value of 0 for the soil boundary to make it permeable and transform it into a drainage boundary; set the top and bottom boundaries of the soil as drainage boundaries, and set the side boundaries as undrained boundaries to simulate soil consolidation and other phenomena.

[0071] Furthermore, the pile-soil contact in ABAQUS / Explicit is modeled using General contact. The tangential behavior of the pile-soil interface is simulated using the Coulomb friction criterion, and the normal behavior is simulated using hard contact. Under partially drained conditions, the calculation of friction is based on the effective stress method; in general, the difference between the total stress value and the effective stress value is about 2 times. Therefore, the friction coefficient under partially drained conditions is reduced and defined as 0.125.

[0072] Furthermore, according to the pile foundation design and construction plan, two analysis steps are set: the first step is the initial ground stress balance: gravity load is applied to the soil to simulate the initial ground stress state of the fine sand layer. The second step is to simulate the vibration piling process: the force control method is used to simulate the actual vibration piling process to constrain the horizontal displacement of the pile body; a vibration frequency of 47 Hz and a peak excitation force of 500 kN are applied to the top of the pile body until the pile body is driven to a depth of 11.5 m.

[0073] In step S304, a numerical model is constructed.

[0074] Specifically, the embodiment of the present invention can use a linear elastic model to simulate the mechanical behavior of the pile, and input relevant model parameters; use a Niemunis-Herle hypoplastic model to simulate the mechanical behavior of the pile, and input relevant model parameters; determine the relative density of fine sand according to indoor geotechnical tests D r The initial porosity ratio is 60%. e 0 is 0.513, and the initial porosity ratio is set to e 0 is set to 0.513, and the maximum intergranular strain R is set to 0.0001. In the Property module of ABAQUS / Explicit, execute the "Create Material" command; in the pop-up Edit Material window: execute the "Depvar" command to set the number of state variables to 35; execute the "User Material" command to enter the relevant parameters of the subplastic model; execute the "Conductivity" and "Specific Heat" commands to define the specific heat c and thermal conductivity Next, in the Job module, follow these steps: Open the Edit Job window; Execute the "General" command and enter the file path of the VUMAT subroutine in User subroutine file. In addition, you can also call the VUMAT subroutine in the INP file to perform the numerical simulation method.

[0075] In step S305, a verification analysis is performed on the model.

[0076] Specifically, the embodiment of the present invention can improve the CEL method, and the node temperature NT11 can reflect the excess pore water pressure ,; According to the layout of monitoring points in the on-site construction, the excess pore water pressure change curve at the corresponding position after the vibration piling process is completed is extracted; when the numerical simulation value and the site monitoring value have a good fitting effect, it proves that the constructed model has accuracy and reliability. Output the numerical calculation results as needed, such as the porosity ratio, excess pore water pressure, effective stress, etc. of the soil, as well as the stress and strain of the pile; according to the pile foundation design and construction plan, change the values ​​of key parameters, study and analyze the physical phenomena in the dynamic piling process and the comprehensive influence of the changes in various parameters on the dynamic piling process.

[0077] Thus, the numerical simulation process of dynamic piling in cohesionless soil based on the secondary development of ABAQUS software was completed.

[0078] The numerical simulation method for dynamic piling in cohesionless soil provided by the embodiment of the present invention can accurately simulate the process of pile driving into soil under dynamic load (such as vibration or impact), the mechanical behavior of cohesionless soil, and the dynamic change of pore water pressure, etc., and realize the modeling and analysis of the dynamic piling process in cohesionless soil. The problems of complex model, numerous parameters, and difficult solution in the solution process of related technologies are solved, and the model complexity and solution difficulty are reduced.

[0079] Next, a numerical simulation system for dynamic piling in cohesionless soil proposed according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0080] Figure 4 Schematic diagram of a numerical simulation system for dynamic piling in cohesionless soil according to an embodiment of the present invention.

[0081] like Figure 4 As shown, the numerical simulation system 10 suitable for dynamic piling in cohesionless soil includes: an acquisition module 100 and a data processing module 200 .

[0082] Among them, the acquisition module 100 is used to obtain the generalized model of dynamic piling and cohesionless soil samples in the target study area; the data processing module 200 is used to determine the subplastic model parameters of cohesionless soil and the linear elastic model parameters of piles, and based on the subplastic model parameters of cohesionless soil and the linear elastic model parameters of piles, the preset VUMAT subroutine is called by the pre-established numerical model to simulate the soil behavior of large deformation of soil and dynamic changes of pore water pressure during dynamic piling, and obtain simulated piling results, wherein the preset VUMAT subroutine is written by the improved CEL method.

[0083] Furthermore, in some embodiments, after obtaining the simulated piling results, the data processing module 200 is also used to: obtain the piling monitoring data of the target study area; and verify the simulated piling results based on the piling monitoring data, so as to perform accuracy analysis on the numerical model according to the verification results.

[0084] Furthermore, in some embodiments, the acquisition module 100 is specifically used to: obtain the site stratigraphic conditions, groundwater conditions and the occurrence state of cohesionless soil in the target study area, and obtain geological condition analysis results based on the site stratigraphic conditions, groundwater conditions and the occurrence state of cohesionless soil; determine pile foundation design parameters based on the geological condition analysis results, wherein the pile foundation design parameters include pile size, material properties, piling equipment and loading parameters; obtain piling monitoring data of the target study area, and obtain a dynamic piling generalization model based on the geological condition analysis results, pile foundation design parameters and piling monitoring data.

[0085] Furthermore, in some embodiments, the data processing module 200 is specifically used to: construct a Niemunis-Herle hypoplastic model based on hypoplastic model parameters of cohesionless soil, and embed the VUMAT subroutine of the Niemunis-Herle hypoplastic model into the preset ABAQUS software to obtain the mechanical behavior simulation results of the cohesionless soil; rewrite the preset pore fluid mass balance equation based on the preset Darcy's law, and replace the temperature in the preset thermal energy balance equation according to the super pore fluid pressure of the rewritten pore fluid mass balance equation, and based on the replaced thermal energy balance equation, analyze the heat conduction transfer process in the thermal-displacement coupling analysis program The diffusion of pore fluid in the soil skeleton is simulated and related stress analysis is performed to determine the improved CEL method in combination with the analysis results, wherein the preset Darcy's law is used to describe the flow of pore fluid between the soil skeletons, and the preset thermal energy balance equation is set in the thermal-displacement coupling analysis program; the preset VUMAT subroutine is determined according to the improved CEL method, and based on the subplastic model parameters of cohesionless soil and the linear elastic model parameters of piles, the preset VUMAT subroutine is called by the pre-established numerical model to simulate the soil behavior of large deformation of soil and dynamic changes of pore water pressure during dynamic piling, and the simulated piling results are obtained in combination with the simulation results of the mechanical behavior of cohesionless soil.

[0086] Further, in some embodiments, before using the pre-established numerical model to call the preset VUMAT subroutine to perform soil behavior simulation results on the large deformation of soil and the dynamic changes of pore water pressure during the dynamic piling process, the data processing module 200 is also used to: based on the generalized model of dynamic piling, perform three-dimensional geometric modeling of piles and soil to obtain modeled piles and modeled soil; based on the preset Lagrangian unit and the preset Euler unit, use the improved CEL method to mesh the modeled piles and modeled soil to obtain meshing results; determine the boundary conditions and pile-soil contact characteristics according to the soil behavior simulation results, and construct the pre-established numerical model based on the meshing results, boundary conditions and pile-soil contact characteristics.

[0087] It should be noted that the above explanation of the embodiment of the numerical simulation method applicable to dynamic pile driving in non-cohesive soil is also applicable to the numerical simulation device applicable to dynamic pile driving in non-cohesive soil of this embodiment, which will not be repeated here.

[0088] The numerical simulation system for dynamic piling in cohesionless soil provided by the embodiment of the present invention can accurately simulate the process of pile driving into soil under dynamic load (such as vibration or impact), the mechanical behavior of cohesionless soil, and the dynamic change of pore water pressure, etc., and realize the modeling and analysis of the dynamic piling process in cohesionless soil. The problems of complex model, numerous parameters, and difficult solution in the solution process of related technologies are solved, and the model complexity and solution difficulty are reduced.

[0089] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0090] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "N" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0091] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0092] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0093] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

Claims

1. A numerical simulation method for dynamic piling in cohesionless soil, characterized in that: The following steps are involved: Obtain a generalized dynamic pile driving model and cohesionless soil samples for the target study area; The subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile are determined, and based on the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, a preset VUMAT subroutine is called by a pre-established numerical model to simulate the soil behavior of large deformation of the soil and the dynamic change of pore water pressure during dynamic piling, so as to obtain a simulated piling result, wherein the preset VUMAT subroutine is written by an improved CEL method.

2. The method according to claim 1, characterized in that After obtaining the simulated piling result, the method further includes: Acquire piling monitoring data of the target study area; Based on the piling monitoring data, the simulated piling results are verified, so as to analyze the accuracy of the numerical model according to the verification results.

3. The method according to claim 1, characterized in that The method of obtaining a generalized dynamic pile driving model for a target research area includes: Obtaining the site stratigraphic conditions, groundwater conditions and the occurrence state of cohesionless soil in the target study area, and obtaining geological condition analysis results based on the site stratigraphic conditions, groundwater conditions and the occurrence state of cohesionless soil; Based on the geological condition analysis results, pile foundation design parameters are determined, wherein the pile foundation design parameters include pile size, material properties, pile driving equipment and loading parameters; The piling monitoring data of the target research area is obtained, and the dynamic piling generalization model is obtained according to the geological condition analysis results, the pile foundation design parameters and the piling monitoring data.

4. The method according to claim 1, characterized in that: Based on the hypoplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, the preset VUMAT subroutine is used to simulate the large deformation of the soil and the dynamic change of the pore water pressure during the dynamic pile driving process to obtain the simulation results of the soil behavior, including: Based on the hypoplastic model parameters of the cohesionless soil, a Niemunis-Herle hypoplastic model is constructed, and the VUMAT subroutine of the Niemunis-Herle hypoplastic model is embedded into the preset ABAQUS software to obtain the mechanical behavior simulation results of the cohesionless soil; Based on the preset Darcy's law, the preset pore fluid mass balance equation is rewritten, and the temperature in the preset thermal energy balance equation is replaced according to the excess pore fluid pressure of the rewritten pore fluid mass balance equation, and based on the replaced thermal energy balance equation, the diffusion of the pore fluid in the soil skeleton is simulated through the heat conduction transfer process in the thermal-displacement coupling analysis program and the related stress analysis is performed, so as to determine the improved CEL method in combination with the analysis results, wherein the preset Darcy's law is used to describe the flow of the pore fluid between the soil skeletons, and the preset thermal energy balance equation is set in the thermal-displacement coupling analysis program; The preset VUMAT subroutine is determined according to the improved CEL method, and based on the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, the preset VUMAT subroutine is called by using a pre-established numerical model to simulate the soil behavior of the large deformation of the soil and the dynamic change of the pore water pressure during the dynamic piling process, and the simulated piling result is obtained in combination with the mechanical behavior simulation result of the cohesionless soil.

5. The method according to claim 4, characterized in that Before using the pre-established numerical model to call the preset VUMAT subroutine to simulate the soil behavior results of the large deformation of the soil and the dynamic change of the pore water pressure during the dynamic pile driving process, it also includes: Based on the generalized model of dynamic pile driving, three-dimensional geometric modeling of piles and soil is performed to obtain modeled piles and modeled soil; Based on the preset Lagrangian unit and the preset Euler unit, the improved CEL method is used to mesh the modeled piles and the modeled soil to obtain a meshing result; Boundary conditions and pile-soil contact characteristics are determined, and the pre-established numerical model is constructed based on the meshing results, the boundary conditions and the pile-soil contact characteristics.

6. A numerical simulation system for dynamic piling in cohesionless soil, characterized in that: include: The acquisition module is used to obtain the generalized model of dynamic pile driving and cohesionless soil samples in the target study area; The data processing module is used to determine the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, and based on the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, use a pre-established numerical model to call a preset VUMAT subroutine to simulate the soil behavior of the large deformation of the soil and the dynamic change of the pore water pressure during the dynamic piling process to obtain a simulated piling result, wherein the preset VUMAT subroutine is written by the improved CEL method.

7. The system according to claim 6, characterized in that After obtaining the simulated piling result, the data processing module is further used to: Acquire piling monitoring data of the target study area; Based on the piling monitoring data, the simulated piling results are verified, so as to analyze the accuracy of the numerical model according to the verification results.

8. The system according to claim 6, characterized in that The acquisition module is specifically used for: Obtaining the site stratigraphic conditions, groundwater conditions and the occurrence state of cohesionless soil in the target study area, and obtaining geological condition analysis results based on the site stratigraphic conditions, groundwater conditions and the occurrence state of cohesionless soil; Based on the geological condition analysis results, pile foundation design parameters are determined, wherein the pile foundation design parameters include pile size, material properties, pile driving equipment and loading parameters; The piling monitoring data of the target research area is obtained, and the dynamic piling generalization model is obtained according to the geological condition analysis results, the pile foundation design parameters and the piling monitoring data.

9. The system according to claim 6, characterized in that The data processing module is specifically used for: Based on the hypoplastic model parameters of the cohesionless soil, a Niemunis-Herle hypoplastic model is constructed, and the VUMAT subroutine of the Niemunis-Herle hypoplastic model is embedded into the preset ABAQUS software to obtain the mechanical behavior simulation results of the cohesionless soil; Based on the preset Darcy's law, the preset pore fluid mass balance equation is rewritten, and the temperature in the preset thermal energy balance equation is replaced according to the excess pore fluid pressure of the rewritten pore fluid mass balance equation, and based on the replaced thermal energy balance equation, the diffusion of the pore fluid in the soil skeleton is simulated through the heat conduction transfer process in the thermal-displacement coupling analysis program and the related stress analysis is performed, so as to determine the improved CEL method in combination with the analysis results, wherein the preset Darcy's law is used to describe the flow of the pore fluid between the soil skeletons, and the preset thermal energy balance equation is set in the thermal-displacement coupling analysis program; The preset VUMAT subroutine is determined according to the improved CEL method, and based on the subplastic model parameters of the cohesionless soil and the linear elastic model parameters of the pile, the preset VUMAT subroutine is called by using a pre-established numerical model to simulate the soil behavior of the large deformation of the soil and the dynamic change of the pore water pressure during the dynamic piling process, and the simulated piling result is obtained in combination with the mechanical behavior simulation result of the cohesionless soil.

10. The system according to claim 6, characterized in that Before using the pre-established numerical model to call the preset VUMAT subroutine to simulate the soil behavior results of the large deformation of the soil and the dynamic change of the pore water pressure during the dynamic pile driving process, the data processing module is also used to: Based on the generalized model of dynamic pile driving, three-dimensional geometric modeling of piles and soil is performed to obtain modeled piles and modeled soil; Based on the preset Lagrangian unit and the preset Euler unit, the improved CEL method is used to mesh the modeled piles and the modeled soil to obtain a meshing result; Boundary conditions and pile-soil contact characteristics are determined, and the pre-established numerical model is constructed based on the meshing results, the boundary conditions and the pile-soil contact characteristics.

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