A load distribution calculation method for a foundation pile column joint

Abstract

The present application relates to the technical field of structural engineering and fan foundation design, and specifically relates to a load distribution calculation method for a foundation pile column node, which comprises defining an input load vector of a main control point and a corresponding spatial six-degree-of-freedom generalized displacement; decoupling the foundation pile column node into two parallel subsystems in terms of physics and stiffness, deriving a single-pile spatial stiffness matrix based on the m method of the Winkler foundation model; constructing a first equivalent stiffness matrix and a second equivalent stiffness matrix; superimposing the matrices of the first equivalent stiffness matrix and the second equivalent stiffness matrix to obtain a global spatial stiffness matrix of the foundation composite system; and calculating a dynamic load distribution ratio of the parallel subsystems. The present application is used to accurately describe the nonlinear interaction between the pile foundation and the foundation, to provide more accurate pile foundation stiffness calculation and load distribution results, and to improve the accuracy and reliability of the load distribution calculation.

Description

Technical Field

[0001] This invention relates to the field of structural engineering and wind turbine foundation design technology, specifically to a method for calculating the load distribution of foundation pile-column joints. Background Technology

[0002] Load distribution calculation at the pile-column joint is a crucial step in pile foundation design, especially under complex loads. Accurately distributing the load to each pile and cap is essential for ensuring structural safety and stability. Existing pile foundation load distribution methods mostly rely on simplified calculation models and empirical formulas. While these methods provide rapid estimates, they cannot fully reflect the complex interaction between the soil and the piles. Therefore, traditional calculation methods often contain certain errors when dealing with complex engineering conditions.

[0003] In pile foundation design, especially in multi-pile foundations or large, complex structures, the interaction between piles and the soil exhibits significant nonlinear characteristics. Particularly for subsystems with different stiffnesses, such as inner and outer pile rings, or rigid and flexible components, the accuracy of load distribution directly impacts the stability and economy of the pile foundation. However, existing load distribution methods largely rely on the assumption of homogeneity of the foundation soil and a linear relationship between pile stiffness, which introduces significant errors for complex foundation systems.

[0004] Furthermore, in multi-pile groups and pile cap structures, the load distribution of pile foundations is influenced not only by soil conditions but also by the combined effects of factors such as the inherent stiffness of the pile foundation structure, the interaction between piles, and the deformation of the pile top and shaft. Currently, although some methods have attempted to describe the overall stiffness of pile foundations through stiffness matrix analysis, these methods typically fail to adequately consider the variation of pile foundation stiffness with depth and its interaction with the foundation soil. Summary of the Invention

[0005] The purpose of this invention is to provide a load distribution calculation method for foundation pile-column joints to solve the above-mentioned technical problems, thereby accurately describing the nonlinear interaction between the pile foundation and the ground, providing more accurate pile stiffness calculation and load distribution results, and thus improving the accuracy and reliability of load distribution calculation.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for calculating load distribution at a foundation pile-column joint includes the following steps: S1. Define the input load vector of the master control point and the corresponding spatial six-degree-of-freedom generalized displacement; S2. Decouple the foundation pile-column joint from both physical and stiffness perspectives into two parallel subsystems, namely subsystem A and subsystem B; calculate the stiffness matrices of subsystem A and subsystem B respectively. S3. Based on the Winkler foundation model, establish the differential equation of single pile force and solve it analytically using the m-method to obtain the flexibility relationship between pile top displacement and internal force, and construct the single pile spatial stiffness matrix based on the flexibility relationship. S4. The single pile spatial stiffness matrix is ​​superimposed in subsystem A to construct the first equivalent stiffness matrix, and then used in subsystem B for pile cap flexible deflection calculation to construct the second equivalent stiffness matrix. S5. At the main control point, superimpose the first equivalent stiffness matrix and the second equivalent stiffness matrix to obtain the global spatial stiffness matrix of the basic composite system. S6. Based on the global spatial stiffness matrix and the input load vector, the spatial six-degree-of-freedom generalized displacement of the main control point is obtained, and then the dynamic load distribution ratio of subsystem A and subsystem B is calculated by substituting them back into subsystem A and subsystem B.

[0007] Furthermore, the input load vector is any one of the vertical load, horizontal load, and bending moment load applied at the main control point, and the spatial six-degree-of-freedom generalized displacement includes the translational displacement and rotational displacement of the main control point.

[0008] Furthermore, subsystem A includes inner ring piles, steel-concrete composite columns and the piles directly below them, while subsystem B includes pile caps, outer ring pile groups and foundation beams and slabs.

[0009] Furthermore, step S3 includes: S31. Calculate the compliance matrix generated at the pile top; S32. Invert the flexibility matrix to output the stiffness matrix of the pile; S33. Based on the axisymmetric characteristics of the circular cross-section of a single pile and the spatial right-hand screw rule, the sign of the stiffness matrix is ​​corrected to generate the spatial stiffness matrix of the single pile.

[0010] Furthermore, the stiffness matrix includes translational shear stiffness, bending stiffness, coupling stiffness, vertical pull-out stiffness, and torsional stiffness.

[0011] Furthermore, the method for constructing the first equivalent stiffness matrix of subsystem A includes: S41. For the i-th stake, based on its spatial position in the global coordinate system, through the geometric transformation matrix... The spatial stiffness matrix of a single pile Switch to the main control point; S42. Based on the geometric transformation matrix, calculate the global contribution stiffness matrix of the i-th pile: Superimpose the global contribution stiffness matrices of all piles to output the first equivalent stiffness matrix: Furthermore, the method for constructing the second equivalent stiffness matrix of subsystem B includes: S43. Divide the pier cap into multiple intervals along the radial direction, and calculate the equivalent bending moment of inertia of the pier cap based on the principle of virtual work. The equivalent bending moment of inertia is obtained by integrating the cross-sectional moment of inertia that varies along the radial direction. S44. Define the moment of inertia of the pier section as a piecewise function that varies radially, where different intervals of the piecewise function correspond to the thick pier column section and the variable cross-section slope section, respectively, and calculate the moment of inertia of the section for each interval based on the cross-sectional geometric parameters. S45. The radial structure of the pier cap is equivalent to several radially distributed beam elements, and an equivalent beam model is constructed based on the equivalent bending moment of inertia. S46. Based on the displacement method of structural mechanics, under given end displacement and rotation boundary conditions, calculate the end shear force and end bending moment of the equivalent beam. S47. Calculate the equivalent bending stiffness of a single radial beam based on the end shear force and end bending moment. S48. Spatial integration is performed on multiple radially distributed beams to obtain the overall bending stiffness of the foundation. S49. Combining the rigid constraint conditions of the outer ring piles, the overall bending stiffness of the pile cap is modified to obtain the second equivalent stiffness matrix of subsystem B. .

[0012] Furthermore, step S5 includes: S51. At the main control point, the first equivalent stiffness matrix is... With the second equivalent stiffness matrix Superimpose to output the global spatial stiffness matrix : S52, By solving the global spatial stiffness matrix and external load vector The relationship is used to obtain the actual spatial six-degree-of-freedom generalized displacement of the master control point: .

[0013] Furthermore, step S6 includes: S61. Based on the displacement compatibility condition, calculate the load distribution between subsystem A and subsystem B: S62. Calculate the bending moment of the inner ring piles in subsystem A based on the load distribution of subsystem A and subsystem B. and subsystem The bending moment of the outer ring piles; calculate the bending moment of the input load vector. ; S63. Calculate the dynamic load distribution ratio of subsystem A: S64. Calculate the dynamic load distribution ratio of subsystem B: .

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention establishes the differential equation of pile foundation force by adopting the Winkler foundation model and the m-method theory, solves the flexibility relationship at the pile top, obtains the stiffness matrix of the pile foundation, and realizes an accurate description of the deformation and internal force distribution of the pile foundation under the action of the soil. This improves the accuracy of load distribution calculation and ensures that the response of the foundation pile joint under different loads can be accurately predicted.

[0015] 2. This invention decouples the physical properties and stiffness of pile-column nodes into subsystems A and B, calculating the stiffness matrix of each subsystem separately. This effectively considers load transfer between subsystems with different stiffness levels, avoiding errors from uniform stiffness processing and thus improving the rationality of load distribution. Furthermore, it makes load distribution calculation more modular, independently calculating the stiffness matrices of subsystems A and B, and superimposing their stiffness matrices to obtain the global stiffness matrix. This not only improves computational efficiency but also makes the load distribution between different parts clearer.

[0016] 3. This invention has wide applications in complex pile foundation structures with different stiffness components, such as the interaction between inner and outer pile rings, pile caps, and pile groups. Through precise modeling and analysis of these complex structures, it provides a more reliable and accurate load distribution scheme, solving the problem of complex load distribution that existing methods cannot accurately handle. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a method for calculating load distribution at a foundation pile-column joint according to the present invention. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0019] like Figure 1 The load distribution calculation method for a foundation pile-column joint shown includes the following steps: S1. Define the load vector as the input load at the main control point, denoted as... Define the global displacement vector as the primary control point at... The spatial six-degree-of-freedom generalized displacement generated by the action The input load vector can be any one of the vertical, horizontal, or bending moment loads applied at the master control point. The spatial six-degree-of-freedom generalized displacement includes the translational and rotational displacements of the master control point. Translational displacements include the translational displacements of the master control point along the x, y, and z axes, while rotational displacements include the rotational displacements of the master control point around the x, y, and z axes. By defining the input load vector at the master control point, initial data is provided for the load analysis of the entire system. Simultaneously, the spatial six-degree-of-freedom generalized displacement is defined to provide fundamental data for mechanical analysis and displacement calculation.

[0020] S2. Decouple the foundation pile-column joints physically and stiffly into two parallel subsystems, subsystem A and subsystem B; calculate the stiffness matrices of subsystem A and subsystem B respectively; subsystem A (through the direct transmission path) includes four steel-concrete composite columns and four inner ring piles directly below them. Kinematic constraints assume that the flange ring at the bottom of the tower has sufficiently large in-plane stiffness. The top center of the four columns is designated as a slave node, bound to the master control point via a rigid arm; the displacement of these four columns is entirely determined by the displacement of the master control point. The load vector shared by this subsystem is denoted as... .

[0021] Subsystem B comprises some columns, foundation beams and slabs, and 24 pile groups arranged around the outer ring of the foundation. The load enters the columns from the main control point, and after elastic flexural deformation of the thick foundation, is transferred to the 24 outer piles. The load vector shared by this subsystem is denoted as... .

[0022] Step S2 simplifies the foundation pile-column joint into two independent parts, subsystem A and subsystem B, to improve computational efficiency. Subsystem A includes a rigid component, while subsystem B includes a flexible component. The stiffness matrices of subsystems A and B are calculated separately to provide a basis for stiffness analysis and load distribution calculations.

[0023] S3. Based on the Winkler foundation model, establish the differential equation of force for a single pile and solve it analytically using the m-method to obtain the flexibility relationship between pile top displacement and internal forces. Based on this flexibility relationship, construct the spatial stiffness matrix of the single pile. The spatial stiffness matrix of the single pile includes translational shear stiffness, vertical tensile / compressive stiffness, bending stiffness, and the coupled stiffness of displacement and rotation. The Winkler foundation model describes the elastic response of the foundation soil and simulates the bending, compression, and shear deformation behavior of the pile foundation. The m-method extends the Winkler model by considering the non-uniformity of the foundation soil and the variation of the resistance coefficient with depth, providing more accurate nonlinear analysis. Step S3 establishes the differential equation of force for a single pile using the Winkler foundation model and the m-method, reflecting the interaction between the foundation and the pile. By analytically solving this differential equation, the flexibility relationship at the pile top is obtained, and the spatial stiffness matrix of the pile is constructed.

[0024] Furthermore, step S3 includes: S31. Treat a single pile as a beam placed on a Winkler elastic foundation, assuming a depth of... z The horizontal resistance coefficient of the foundation soil at the location is And establish the differential equation of force on a single pile: Where E is the elastic modulus of the pile, I is the moment of inertia of the pile, m is the parameter representing the variation of the horizontal resistance coefficient of the foundation soil with depth, and x is the horizontal displacement function of the pile. This is the displacement amplitude coefficient; Introducing core dimensionless parameters: When the product of the core dimensionless parameter and the pile's penetration depth L satisfies the elastic long pile boundary condition, the single pile force differential equation is solved analytically, and the flexibility matrix generated at the pile top is output. Each term of the flexibility matrix reflects the stiffness of the pile in different directions. S32. Invert the flexibility matrix to output the stiffness matrix of the pile; S33. Based on the axisymmetric characteristics of the circular cross-section of a single pile and the spatial right-hand screw rule, the sign of the stiffness matrix is ​​corrected to generate the spatial stiffness matrix of the single pile. The stiffness matrix includes translational shear stiffness, bending stiffness, coupling stiffness, vertical tensile stiffness, and torsional stiffness. A core dimensionless parameter (the deformation coefficient of the pile) is introduced. When satisfied At that time, the boundary conditions of the elastic long pile were solved analytically. By solving the series solution of the differential equation, the inverse of the flexibility matrix generated at the pile top was obtained, yielding the absolute analytical solution of the stiffness coefficients: Translational shear stiffness: ; Bending stiffness: ; Coupling stiffness: ; Vertical compressive / extension stiffness: Assuming linear distribution of side skin friction and elastic support at the pile end, the stiffness formula is as follows: ; Torsional stiffness: To balance solution accuracy and matrix iteration efficiency, the torsional stiffness of a single pile is simplified analytically to a constant stiffness based on the integral of the initial elastic shear modulus. .

[0025] in: : The elastic axial compressive stiffness of the pile itself; : No. i The stiffness coefficient of the side friction of the soil layer; : Support stiffness coefficient of the soil at the pile tip.

[0026] : Torsional contribution of the pile side. According to the theory of torsional displacement attenuation of a cylinder, the torsional stiffness per unit depth of the pile side is: By integrating along the pile length L, the torsional contribution of the entire side surface can be obtained.

[0027] : Torsional contribution at the pile tip. Based on the analytical solution of torsion of a rigid disk on an elastic half-surface, its torsional stiffness is... .

[0028] D and L: are the outer diameter and depth of penetration of a single pile, respectively.

[0029] or Finally, based on the axisymmetric characteristics of the circular cross-section of a single pile and the spatial right-hand screw rule, the sign is corrected to generate a complete three-dimensional 6x6 single pile spatial stiffness matrix.

[0030] S4. The spatial stiffness matrix of a single pile is superimposed in subsystem A to construct a first equivalent stiffness matrix, which is then used in subsystem B for the pile cap flexible deflection calculation to construct a second equivalent stiffness matrix; thus, the stiffness information of a single pile is effectively integrated into the overall stiffness calculation of the foundation pile-column joint. Further, the method for constructing the first equivalent stiffness matrix of subsystem A includes: S41. For the i-th stake, based on its spatial position in the global coordinate system, through the geometric transformation matrix... The spatial stiffness matrix of a single pile Switch to the main control point; The planar coordinates of the i-th pile in the global coordinate system are: , Its geometric transformation matrix for: S42. Based on the geometric transformation matrix, calculate the global contribution stiffness matrix of the i-th pile: Superimpose the global contribution stiffness matrices of all piles to output the first equivalent stiffness matrix: Furthermore, the method for constructing the second equivalent stiffness matrix of subsystem B includes: S43. Divide the pier cap into multiple intervals along the radial direction, and calculate the equivalent bending moment of inertia of the pier cap based on the principle of virtual work. The equivalent bending moment of inertia is obtained by integrating the cross-sectional moment of inertia that varies along the radial direction. S44. Define the moment of inertia of the pier section as a piecewise function that varies radially, where different intervals of the piecewise function correspond to the thick pier column section and the variable cross-section slope section, respectively, and calculate the moment of inertia of the section for each interval based on the cross-sectional geometric parameters. S45. The radial structure of the pier cap is equivalent to several radially distributed beam elements, and an equivalent beam model is constructed based on the equivalent bending moment of inertia. S46. Based on the displacement method of structural mechanics, under given end displacement and rotation boundary conditions, calculate the end shear force and end bending moment of the equivalent beam. S47. Calculate the equivalent bending stiffness of a single radial beam based on the end shear force and end bending moment. S48. Spatial integration is performed on multiple radially distributed beams to obtain the overall bending stiffness of the foundation. S49. Combining the rigid constraint conditions of the outer ring piles, the overall bending stiffness of the pile cap is modified to obtain the second equivalent stiffness matrix of subsystem B. .

[0031] Specifically, the calculation steps for the flexible deflection reduction of subsystem B are as follows: The foundation is divided into different intervals. 0-3m is the tower stiffness superposition section; 3-4m is the fixed-section beam section along the outer edge of the foundation column; and 4-9m is the inverted T-shaped variable-section beam section. Based on the principle of virtual work, the equivalent bending moment of inertia is the harmonic mean of its flexibility integral: Among them, the moment of inertia of the local section It is a piecewise function: Interval 1 ( (i.e., the thick platform section) Interval 2 ( (i.e., the variable cross-section sloping section): Calculated using the inverted T-section parallel axis shifting formula. Assume the net height of the web... It decreases linearly, and the height of the neutral axis is : For the basic form simplified to beams with N equally spaced radial distributions, the "displacement method" of structural mechanics is employed. When the entire foundation rotates around the Y-axis The angle between the hour and the X-axis is A radial main beam. At the inner starting point. The boundary conditions imposed on this beam by the rigid pedestal are: Vertical downward displacement: End section rotation angle: At the outermost endpoint, it is assumed that the outer ring pile group is embedded in the solid pole: the displacement is 0 and the rotation angle is 0.

[0032] Extract the internal forces at the ends of a single beam. According to the displacement method in structural mechanics, a section of length is... The bending moment of inertia is When the aforementioned boundary displacement occurs, shear force will be generated at the ends of the beam. and bending moment .

[0033] Total bending moment Also includes shear force Provided bending moment: Obtain the equivalent flexural stiffness of a single beam in the overturning plane. : The resisting moment vector of a single beam is not on the global Y-axis and needs to be projected: .

[0034] Spatial integration superposition of N uniformly distributed radial beams ( ), thus obtaining the final perfect analytical closure formula: The true equivalent bending stiffness of subsystem B The rotation term in the text should be corrected to: S5. At the main control point, superimpose the first equivalent stiffness matrix and the second equivalent stiffness matrix to obtain the global spatial stiffness matrix of the foundation composite system. Step S5 combines the stiffness matrices of subsystem A and subsystem B to reflect the overall stiffness characteristics of the foundation pile-column joint. The global spatial stiffness matrix provides stiffness information for load distribution calculation. Further, step S5 includes: S51. At the main control point, the first equivalent stiffness matrix is... With the second equivalent stiffness matrix Superimpose to output the global spatial stiffness matrix : S52, By solving the global spatial stiffness matrix and external load vector The relationship is used to obtain the actual spatial six-degree-of-freedom generalized displacement of the master control point: .

[0035] S6. Based on the global spatial stiffness matrix and the input load vector, the spatial six-degree-of-freedom generalized displacement of the main control point is obtained. This displacement is then substituted back into subsystems A and B to calculate the dynamic load distribution ratio between them. This ensures that the load is reasonably distributed within the system and takes into account the stiffness influence of the subsystems.

[0036] Furthermore, step S6 includes: S61. Based on the displacement compatibility condition, calculate the load distribution between subsystem A and subsystem B: S62. Calculate the bending moment of the inner ring piles in subsystem A based on the load distribution of subsystem A and subsystem B. and subsystem The bending moment of the outer ring piles; calculate the bending moment of the input load vector. ; S63. Calculate the dynamic load distribution ratio of subsystem A: S64. Calculate the dynamic load distribution ratio of subsystem B: .

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0039] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the nature and scope of the present invention. Various modifications made to the above embodiments by those skilled in the art after reading this specification are all within the scope of protection of the present invention.

Claims

1. A method for calculating load distribution at a foundation pile-column joint, characterized in that, Includes the following steps: S1. Define the input load vector of the master control point and the corresponding spatial six-degree-of-freedom generalized displacement; S2. Decouple the foundation pile node from physical and stiffness perspective into two parallel subsystems, including subsystem A and subsystem B; calculate the stiffness matrix of subsystem A and subsystem B respectively; S3. Based on the Winkler foundation model and the m-method theory, obtain the flexibility relationship between pile top displacement and internal force, and construct the single pile spatial stiffness matrix based on the flexibility relationship. S4. The single pile spatial stiffness matrix is ​​superimposed in subsystem A to construct a first equivalent stiffness matrix, and then used in subsystem B for pile cap flexible deflection calculation to construct a second equivalent stiffness matrix. S5. At the main control point, the first equivalent stiffness matrix and the second equivalent stiffness matrix are superimposed to obtain the global spatial stiffness matrix of the basic composite system. S6. Based on the global spatial stiffness matrix and the input load vector, the spatial six-degree-of-freedom generalized displacement of the main control point is obtained, and then the dynamic load distribution ratio of the subsystem A and subsystem B is calculated by substituting them back into the subsystem A and subsystem B.

2. The method for calculating load distribution at a foundation pile-column joint according to claim 1, characterized in that, The input load vector is any one of the vertical load, horizontal load, and bending moment load applied at the main control point, and the spatial six-degree-of-freedom generalized displacement includes the translational displacement and rotational displacement of the main control point.

3. The method for calculating load distribution at a foundation pile-column joint according to claim 1, characterized in that, Subsystem A includes inner ring piles, steel-concrete composite columns and the piles directly below them, and subsystem B includes a pile cap, outer ring pile group and foundation beams and slabs.

4. The method for calculating load distribution at a foundation pile-column joint according to claim 1, characterized in that, Step S3 includes: S31. Calculate the pile top flexibility matrix of the long pile; S32. Invert the flexibility matrix to output the stiffness matrix of the pile; S33. Based on the axisymmetric characteristics of the circular cross-section of a single pile and the spatial right-hand screw rule, the sign of the stiffness matrix is ​​corrected to generate the spatial stiffness matrix of the single pile.

5. The method for calculating load distribution at a foundation pile-column joint according to claim 4, characterized in that, The stiffness matrix includes translational shear stiffness, bending stiffness, coupling stiffness, vertical pull-out stiffness, and torsional stiffness.

6. The method for calculating load distribution at a foundation pile-column joint according to claim 1, characterized in that, The method for constructing the first equivalent stiffness matrix of subsystem A includes: S41. For the i-th stake, based on its spatial position in the global coordinate system, through the geometric transformation matrix... The spatial stiffness matrix of the single pile Switch to the main control point; S42. Based on the geometric transformation matrix, calculate the global contribution stiffness matrix of the i-th pile: Superimpose the global contribution stiffness matrices of all piles to output the first equivalent stiffness matrix: 。 7. The method for calculating load distribution at a foundation pile-column joint according to claim 1, characterized in that, The method for constructing the second equivalent stiffness matrix of subsystem B includes: S43. Divide the pier cap into multiple intervals along the radial direction, and calculate the equivalent bending moment of inertia of the pier cap based on the principle of virtual work. The equivalent bending moment of inertia is obtained by integrating the moment of inertia of the cross section that varies along the radial direction. S44. Define the moment of inertia of the pier section as a piecewise function that varies radially, wherein different intervals of the piecewise function correspond to the thick pier column section and the variable cross-section slope section, respectively, and calculate the moment of inertia of each interval based on the cross-sectional geometric parameters. S45. The radial structure of the pier is equivalent to several radially distributed beam elements, and an equivalent beam model is constructed based on the equivalent bending moment of inertia. S46. Based on the structural mechanics displacement method, under given end displacement and rotation boundary conditions, calculate the end shear force and end bending moment of the equivalent beam; S47. Based on the end shear force and end bending moment, calculate the equivalent bending stiffness of a single radial beam; S48. Spatial integration is performed on multiple radially distributed beams to obtain the overall bending stiffness of the foundation. S49. Combining the rigid constraint conditions of the outer ring piles, the overall bending stiffness of the pile cap is modified to obtain the second equivalent stiffness matrix of the subsystem B. .

8. The method for calculating load distribution at a foundation pile-column joint according to claim 1, characterized in that, Step S5 includes: S51. At the main control point, the first equivalent stiffness matrix is... With the second equivalent stiffness matrix Superimpose and output the global spatial stiffness matrix. : S52, By solving the global spatial stiffness matrix and the external load vector Based on the relationship, the actual spatial six-degree-of-freedom generalized displacement of the main control point is obtained: 。 9. The method for calculating load distribution at a foundation pile-column joint according to claim 8, characterized in that, Step S6 includes: S61. Based on the displacement compatibility condition, calculate the load distribution between subsystem A and subsystem B: S62. Calculate the bending moment of the inner ring piles of subsystem A based on the load distribution of subsystem A and subsystem B. and subsystem The bending moment of the outer ring piles; calculate the bending moment of the input load vector. ; S63. Calculate the dynamic load distribution ratio of subsystem A: S64. Calculate the dynamic load distribution ratio of subsystem B: 。

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