Unsaturated viscoelastic soil model-based torsional vibration analysis method and device for partially embedded pile and electronic equipment

Abstract

The invention provides a torsional vibration analysis method and device for a partially embedded pile based on an unsaturated viscoelastic soil model and electronic equipment. The torsional vibration analysis method for the partially-embedded pile based on the unsaturated viscoelastic soil model comprises the steps that assumed conditions are set; based on the assumed conditions and the three-dimensional continuous medium theory, a control equation of a transverse isotropic unsaturated fractional derivative viscoelastic soil body based on a Biot type is established, and a pile body torsional vibration control equation based on an Euler-Bernoulli rod and partially buried in soil and partially exposed out of the ground surface is established; and based on a separation variable method, torsional vibration of part of the embedded piles is analyzed. Through an innovative method based on a transverse isotropic unsaturated viscoelastic soil model, an accurate analysis means is provided to support application in partial embedded pile design and engineering practice, so that the purpose of improving construction efficiency and engineering quality is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of engineering technology, and in particular relates to a torsional vibration analysis method, device and electronic equipment for partially embedded piles based on an unsaturated viscoelastic soil model. Background Art

[0002] In modern engineering practice, partially buried piles are widely used in various foundation projects, such as bridges, docks, high-speed railways, etc. Compared with fully buried piles, partially buried piles have unique engineering advantages. They can not only bear loads below the surface, but also expose the surface through the top of the pile, which is convenient for structural connection and maintenance, thereby saving material costs, simplifying construction processes, and improving the flexibility and maintainability of the project. The pile body is partially separated from the soil constraint, resulting in significant differences in its force and deformation compared with fully buried piles. Therefore, there is a large gap between the research on the dynamic characteristics of partially buried piles and their engineering applications. In the design and analysis of partially buried piles, the characteristics of the soil around the pile body are crucial to its torsional vibration response. Unsaturated viscoelastic soil is a common type of soil around the pile. Its transverse isotropy, viscoelasticity, and the viscosity and inertial coupling effects between the solid-liquid-gas phase directly affect the torsional characteristics of the pile. Accurate description and understanding of these soil characteristics are crucial to effectively predict and optimize the response of partially buried piles under dynamic loads. The existing technology lacks the torsional vibration analysis of partially buried piles by unsaturated viscoelastic soil. Summary of the invention

[0003] In response to the problems existing in the prior art, the present invention provides a method, device and electronic equipment for torsional vibration analysis of partially embedded piles based on an unsaturated viscoelastic soil model, which at least partially solves the problem of lack of torsional vibration analysis of partially embedded piles in unsaturated viscoelastic soil in the prior art.

[0004] In a first aspect, an embodiment of the present invention provides a torsional vibration analysis method for partially embedded piles based on an unsaturated viscoelastic soil model, comprising:

[0005] Step S1: setting assumptions, the assumptions are as follows: establishing a torsional vibration response model of a partially buried pile based on an unsaturated viscoelastic soil model, assuming that the soil around the pile is a transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type, the liquid and gas phase flows conform to the generalized Darcy law, the pile body is an elastic circular rod with zero displacement at the bottom of the pile, part of which is buried in the soil and part of which is exposed on the surface, the displacement and stress of the pile-soil interface are continuous during the torsional vibration process, the pile-soil system conforms to the small deformation assumption, and only the circumferential displacement around the pile is considered;

[0006] Step S2: Based on the above assumptions and three-dimensional continuum theory, a control equation for the transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type is established, and a control equation for the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface is established based on the Euler-Bernoulli rod;

[0007] Step S3: Based on the separation of variables method, the control equation of the transversely isotropic unsaturated fractional derivative viscoelastic soil is solved, and the control equation of the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface is derived, and the complex stiffness and velocity response function of the pile top in the frequency domain, as well as the velocity and displacement time history curves of the pile top under the semi-sine excitation load in the time domain are obtained, so as to analyze the torsional vibration of the partially buried pile.

[0008] Optionally, the torsional vibration control equation of the pile body exposed to the surface in step S2 is:

[0009] ,

[0010] Where φ1 is the torsion angle of the exposed part of the pile, h1 is the length of the exposed part of the pile, z and t represent the displacement and time functions respectively. is the turning shear wave velocity, , is the shear modulus of the pile body, is the pile density.

[0011] Optionally, the torsional vibration control equation of the pile body partially buried in the soil in step S2 is:

[0012] ,

[0013] Where φ2 is the torsion angle of the buried pile, h2 is the buried length of the pile, f(z) is the lateral friction of the soil on the pile, r0 is the radius of the pile, and the polar moment of inertia is .

[0014] Optionally, in step S2, the boundary conditions between the pile and the soil, and the pile-soil and pile-pile continuity conditions include:

[0015] The top and bottom boundary conditions of unsaturated soil, the displacement boundary conditions of unsaturated soil at infinity, the top and bottom boundary conditions of exposed and buried piles, and the pile-soil continuity conditions.

[0016] Optionally, the boundary conditions of the top and bottom surfaces of the unsaturated soil are:

[0017] ,

[0018] .

[0019] Optionally, the displacement boundary condition of the unsaturated soil at infinity is:

[0020] .

[0021] Optionally, the pile top and pile bottom boundary conditions of the exposed and embedded piles are:

[0022] ,

[0023] .

[0024] Optionally, the pile-soil continuity condition is:

[0025] ,

[0026] ,

[0027] in, represents the elastic constant tensor element for a transversely isotropic material, and represent the model parameters of the fractional derivative viscoelastic constitutive model respectively.

[0028] In a second aspect, an embodiment of the present invention further provides a torsional vibration analysis device for partially embedded piles based on an unsaturated viscoelastic soil model, comprising:

[0029] The conditional assumption module is used to set the assumptions. The assumptions are as follows: establish a torsional vibration response model of a partially buried pile based on an unsaturated viscoelastic soil model. Assume that the soil around the pile is a transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type. The liquid and gas flows conform to the generalized Darcy law. The pile body is an elastic circular rod with zero displacement at the bottom of the pile. One part of the pile is buried in the soil and the other part is exposed on the surface. The displacement and stress of the pile-soil interface are continuous during the torsional vibration process. The pile-soil system conforms to the small deformation assumption. Only the circumferential displacement around the pile is considered.

[0030] Establish a module for establishing the governing equations of the transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type based on the above assumptions and the three-dimensional continuum theory, and establishing the governing equations of the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface based on the Euler-Bernoulli rod;

[0031] The analysis module is used to solve the control equation of the transversely isotropic unsaturated fractional derivative viscoelastic soil based on the separation of variables method, and derive the control equation of the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface, obtain the complex stiffness and velocity response function of the pile top in the frequency domain, and the velocity and displacement time history curve of the pile top under the semi-sine excitation load in the time domain, so as to analyze the torsional vibration of the partially buried pile.

[0032] In a third aspect, an embodiment of the present invention further provides an electronic device, the electronic device comprising:

[0033] at least one processor; and,

[0034] a memory communicatively connected to the at least one processor; wherein,

[0035] The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the torsional vibration analysis method of partially embedded piles based on the unsaturated viscoelastic soil model as described in any one of the first aspects.

[0036] The present invention provides a torsional vibration analysis method, device and electronic equipment for partially embedded piles based on an unsaturated viscoelastic soil model, wherein the torsional vibration analysis method for partially embedded piles based on an unsaturated viscoelastic soil model provides accurate analysis means through an innovative method based on a transversely isotropic unsaturated viscoelastic soil model to support the application in the design of partially embedded piles and engineering practice, thereby achieving the purpose of improving construction efficiency and engineering quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0038] Figure 1 It is a schematic diagram of an unsaturated viscoelastic soil model disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0040] It should be clear that the following embodiments of the present invention are described by specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention.

[0041] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. It should be understood by those skilled in the art based on the invention that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0042] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention. The illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0043] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0044] For ease of understanding, Figure 1 As shown, this embodiment discloses a torsional vibration analysis method for partially embedded piles based on an unsaturated viscoelastic soil model, comprising the following steps:

[0045] Step S1: Introduce the following assumptions to establish a torsional vibration response model of a partially buried pile based on an unsaturated viscoelastic soil model: assume that the soil around the pile is a transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type, and the flow of liquid and gas phases conforms to the generalized Darcy's law; the pile body is an elastic circular rod with zero displacement at the pile bottom, part of which is buried in the soil and part of which is exposed on the surface; the displacement and stress of the pile-soil interface are continuous during the torsional vibration process, the pile-soil system conforms to the small deformation assumption, and only the circumferential displacement around the pile is considered.

[0046] Step S2: Based on the three-dimensional continuum theory, the control equation of the transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type is established; the control equation of the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface is established based on the Euler-Bernoulli rod;

[0047] According to the assumption in step S1, the governing equation of the transversely isotropic unsaturated fractional derivative viscoelastic soil in step 2 is:

[0048] (1a),

[0049] (1b),

[0050] (1c),

[0051] (1d),

[0052] (1e), (1f),

[0053] In the formula, A 11 , A 12 , A 13 , A 33 , A 44 and A 66 Represents the elastic constant tensor elements of a transversely isotropic material; represents the soil stress tensor and displacement components around the pile; p w and p a Represents pore water pressure and pore gas pressure; K s represents the bulk modulus of the solid skeleton; , , and represent the model parameters of the fractional derivative viscoelastic constitutive model respectively; represents the α-order Riemann-Liouville fractional derivative, which is expressed as:

[0054] (2),

[0055] The control equation for the torsional vibration of the pile body exposed to the ground in step S2 is:

[0056] (3),

[0057] Where φ1 is the torsion angle of the exposed part of the pile body, is the turning shear wave velocity, is the shear modulus of the pile body, is the pile density.

[0058] The torsional vibration equation of the embedded pile in step S2 is:

[0059] (4),

[0060] Where φ2 is the torsion angle of the buried pile, f(z) is the lateral friction of the soil on the pile, r0 is the radius of the pile, .

[0061] According to the assumptions in step S1, the motion equation of unsaturated soil in the cylindrical coordinate system is established based on porous media theory:

[0062] (5),

[0063] In the formula, , n represents the soil porosity, S r Indicates saturation, It represents the absolute mass density of soil skeleton, liquid phase and gas phase.

[0064] According to the assumptions in step S1, the seepage continuity equation of pore water and pore gas in unsaturated porous media can be derived using the generalized Darcy law:

[0065] (6a),

[0066] (6b),

[0067] In the formula, , , and represent the viscosity coefficient respectively; , represents the intrinsic permeability, α, m and k represent the van

[0068] Genuchten parameter, p c Represents matrix suction.

[0069] Step S3: Based on the separation of variables method, the dynamic control equation of the transversely isotropic unsaturated fractional derivative viscoelastic soil in step S2 is solved, and the torsional vibration control equation of the pile body partially buried in the soil and partially exposed on the surface is derived, the complex stiffness and velocity response function of the pile top in the frequency domain, and the velocity and displacement time history curves of the pile top under the semi-sinusoidal excitation load in the time domain are obtained, and the torsional vibration of the partially buried pile is analyzed.

[0070] In step S2, the boundary conditions between pile and soil and the pile-soil and pile-pile continuity conditions are:

[0071] Unsaturated soil top and bottom boundary conditions:

[0072] (7a),

[0073] (7b),

[0074] Displacement boundary conditions at infinity for unsaturated soil:

[0075] (8),

[0076] Boundary conditions of pile top and pile bottom for exposed and buried piles:

[0077] (9a),

[0078] (9b),

[0079] The pile-soil continuity condition is:

[0080] (10a),

[0081] (10b),

[0082] Step S3 includes the following specific steps:

[0083] Step S31: Based on the assumptions in step S1, the governing equations of the transversely isotropic unsaturated fractional derivative viscoelastic soil are obtained by combining equations (1) and (3):

[0084] (11a),

[0085] (11b),

[0086] (11c),

[0087] Combining equations (11a), (11b) and (11c), we get:

[0088] (12),

[0089] In the formula, , , .

[0090] Using the separation of variables method, we can obtain:

[0091] (13),

[0092] Substituting formula (13) into formula (12), we can obtain:

[0093] (14),

[0094] In the formula, Reflects the degree of anisotropy of the material.

[0095] Equation (14) can be reformulated as differential equation (15) and modified Bessel equation (16):

[0096] (15),

[0097] (16),

[0098] The constants p and q must satisfy the following relationship:

[0099] (17),

[0100] By solving equations (15) and (16), we obtain:

[0101] (18),

[0102] (19),

[0103] Where A, B, C and D are arbitrary constants whose values ​​depend on the boundary conditions; and denote the modified Bessel functions of the first and second kind, respectively.

[0104] By substituting equations (18) and (19) into (13), and combining equations (7a) and (7b), we obtain:

[0105] (20),

[0106] (twenty one),

[0107] By solving the simultaneous equations (18)-(21), the general solution of equation (12) is:

[0108] (twenty two),

[0109] In the formula, A n Corresponds to a series of constants.

[0110] Combining equation (10) and equation (22), we can get:

[0111] (twenty three),

[0112] In the formula, is the second-order form of the modified Bessel function of the second kind.

[0113] Step S32: Since the study is a harmonic load, equation (3) can be further simplified as:

[0114] (twenty four),

[0115] Solving the dynamic control equation (24) for the exposed pile section, the torsion angle at the pile top is obtained as:

[0116] (25),

[0117] Substituting formula (23) into formula (4), we can obtain:

[0118] (26),

[0119] Solving equation (26), we can obtain the torsion angle of the pile on the soil surface:

[0120] (27),

[0121] In the formula, , .

[0122] According to the relationship between the torsion angle and torque of the pile, the torque of the exposed pile section is:

[0123] (28),

[0124] Step S33: For the exposed section, according to the relationship between the torsion angle and torque at the pile top (z = -h1) and the exposed section pile bottom (z = 0), it can be obtained:

[0125] (29),

[0126] In the formula, , .

[0127] Substituting equations (22) and (27) into equation (10a), we obtain:

[0128] (30),

[0129] In the formula, , ,

[0130] .

[0131] Substituting the relationship between the variables in formula (30) into formula (27), the expression of the torsion angle at the top of the buried pile can be further obtained as:

[0132] (31),

[0133] In the formula,

[0134] (32a), (32b),

[0135] (32c),

[0136] The torque at any point of the buried pile can be expressed as:

[0137] (33),

[0138] Step S34: According to the boundary conditions of claim 2, by setting z = 0 and z = h2 in the above equation and eliminating the unknown parameters M2 and N2, the relationship between the torsion angle and the torque at the top and bottom of the buried pile can be obtained:

[0139] (34),

[0140] In the formula,

[0141] (35a),

[0142] (35b),

[0143] Step S35: According to the boundary of the pile at the exposed section and the buried section (z = 0), the torsion angle and torque of the pile meet the continuity condition, that is:

[0144] (36),

[0145] For the pile top subjected to harmonic load T(t)=T0e iωtIn the case where T(-h1)=T0, substituting equations (29) and (34) into equation (36), we obtain:

[0146] (37),

[0147] In the formula, .

[0148] Since the bottom of the buried pile is fixed on the bedrock, the torsion angle of the pile bottom is zero (that is, when h2=0, φ2=0). Therefore, equation (37) can be rewritten as:

[0149] (38),

[0150] Step S36: According to the boundary conditions of claim 2, the exposed pile top satisfies the following relationship:

[0151] (39),

[0152] Therefore, the torsional complex impedance of the exposed pile top is:

[0153] (40),

[0154] in, represents the dimensionless torsional complex impedance at the pile top, and its expression can be written as:

[0155] (41),

[0156] In the formula, parameter K reflects the actual stiffness of the pile and describes the ability of the pile-soil system to resist longitudinal deformation. C represents the dynamic damping at the top of the pile, which reflects the energy dissipation of stress waves, body waves and surface waves radiated to the infinite field during the excitation of the top of the pile. Dynamic stiffness and damping are key parameters that reflect the dynamic characteristics of the pile-soil system under small strain conditions and play a vital role in the seismic isolation design of the superstructure supported by the pile foundation.

[0157] Step S37: The expression of the pile top velocity admittance is as follows:

[0158] (42),

[0159] In the formula, is the dimensionless parameter of velocity admittance, and its specific expression is:

[0160] (43),

[0161] Step S38: The torque applied to the pile top during the excitation process is usually simplified to a half-sine acceleration pulse, expressed as:

[0162] (44),

[0163] By using the inverse Fourier transform and convolution theorem, the velocity response function of the pile top can be effectively derived, which can be used to detect the integrity of the pile body. The specific expression is:

[0164] (45),

[0165] The expression of dimensionless velocity response can be expressed as:

[0166]

[0167] Where H is the total length of the exposed section and the buried section. , , , .

[0168] The embodiment of the present invention is a torsional dynamic complex impedance calculation system for partially embedded piles based on an unsaturated viscoelastic soil model. The soil around the pile adopts a transversely isotropic unsaturated fractional derivative viscoelastic constitutive model, which can reasonably consider the unsaturated characteristics of the soil medium around piles commonly used in engineering and the characteristics of partially embedded piles. The disclosed method can also realize the degradation of soil (single-phase soil, saturated soil, elastic soil and classical viscoelastic soil) and the degradation of piles (completely embedded piles). It has a wide range of applications and can provide a theoretical basis for dynamic detection of piles.

[0169] In addition, this embodiment also discloses a torsional vibration analysis device for partially embedded piles based on an unsaturated viscoelastic soil model, comprising:

[0170] The conditional assumption module is used to set the assumptions. The assumptions are as follows: establish a torsional vibration response model of a partially buried pile based on an unsaturated viscoelastic soil model. Assume that the soil around the pile is a transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type. The liquid and gas flows conform to the generalized Darcy law. The pile body is an elastic circular rod with zero displacement at the bottom of the pile. One part of the pile is buried in the soil and the other part is exposed on the surface. The displacement and stress of the pile-soil interface are continuous during the torsional vibration process. The pile-soil system conforms to the small deformation assumption. Only the circumferential displacement around the pile is considered.

[0171] Establish a module for establishing the governing equations of the transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type based on the above assumptions and the three-dimensional continuum theory, and establishing the governing equations of the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface based on the Euler-Bernoulli rod;

[0172] The analysis module is used to solve the control equation of the transversely isotropic unsaturated fractional derivative viscoelastic soil based on the separation of variables method, and derive the control equation of the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface, obtain the complex stiffness and velocity response function of the pile top in the frequency domain, and the velocity and displacement time history curve of the pile top under the semi-sine excitation load in the time domain, so as to analyze the torsional vibration of the partially buried pile.

[0173] An embodiment of the present invention further provides an electronic device, the electronic device comprising:

[0174] at least one processor; and,

[0175] a memory communicatively connected to the at least one processor; wherein,

[0176] The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute all or part of the steps of the torsional vibration analysis method of partially embedded piles based on the unsaturated viscoelastic soil model disclosed in this embodiment.

[0177] In the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. The block diagrams of the devices, devices, equipment, and systems involved in the present invention are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0178] Additionally, as used herein, "or" used in a list of items beginning with "at least one" indicates a separate list, so that, for example, a list of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word "exemplary" does not mean that the example described is preferred or better than other examples.

[0179] It should also be noted that in the system and method of the present invention, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present invention.

[0180] Various changes, substitutions, and modifications of the techniques described herein may be made without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of the present invention is not limited to the specific aspects of the processes, machines, manufactures, compositions of events, means, methods, and actions described above. Currently existing or later to be developed processes, machines, manufactures, compositions of events, means, methods, or actions that perform substantially the same functions or achieve substantially the same results as the corresponding aspects described herein may be utilized. Thus, the appended claims include such processes, machines, manufactures, compositions of events, means, methods, or actions within their scope.

[0181] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0182] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for torsional vibration analysis of partially embedded piles based on an unsaturated viscoelastic soil model, characterized in that: include: Step S1: setting assumptions, the assumptions are as follows: establishing a torsional vibration response model of a partially buried pile based on an unsaturated viscoelastic soil model, assuming that the soil around the pile is a transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type, the liquid and gas phase flows conform to the generalized Darcy law, the pile body is an elastic circular rod with zero displacement at the bottom of the pile, part of which is buried in the soil and part of which is exposed on the surface, the displacement and stress of the pile-soil interface are continuous during the torsional vibration process, the pile-soil system conforms to the small deformation assumption, and only the circumferential displacement around the pile is considered; Step S2: Based on the above assumptions and three-dimensional continuum theory, a control equation for the transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type is established, and a control equation for the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface is established based on the Euler-Bernoulli rod; Step S3: Based on the separation of variables method, the control equation of the transversely isotropic unsaturated fractional derivative viscoelastic soil is solved, and the control equation of the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface is derived, and the complex stiffness and velocity response function of the pile top in the frequency domain, as well as the velocity and displacement time history curves of the pile top under the semi-sine excitation load in the time domain are obtained, so as to analyze the torsional vibration of the partially buried pile.

2. The torsional vibration analysis method of partially embedded piles based on unsaturated viscoelastic soil model according to claim 1 is characterized in that: The control equation for the torsional vibration of the pile body exposed to the ground in step S2 is: ， Where φ1 is the torsion angle of the exposed part of the pile, h1 is the length of the exposed part of the pile, z and t represent the displacement and time functions respectively. is the turning shear wave velocity, , is the shear modulus of the pile body, is the pile density.

3. The torsional vibration analysis method of partially embedded piles based on unsaturated viscoelastic soil model according to claim 2 is characterized in that: The control equation for the torsional vibration of the pile body partially buried in the soil in step S2 is: ， Where φ2 is the torsion angle of the buried pile, h2 is the buried length of the pile, f(z) is the lateral friction of the soil on the pile, r0 is the radius of the pile, and the polar moment of inertia is .

4. The torsional vibration analysis method of partially embedded piles based on unsaturated viscoelastic soil model according to claim 3 is characterized in that: In step S2, the boundary conditions between pile and soil, pile-soil and pile-pile continuity conditions include: The top and bottom boundary conditions of unsaturated soil, the displacement boundary conditions of unsaturated soil at infinity, the top and bottom boundary conditions of exposed and buried piles, and the pile-soil continuity conditions.

5. The torsional vibration analysis method of partially embedded piles based on unsaturated viscoelastic soil model according to claim 4 is characterized in that: The boundary conditions of the top and bottom surfaces of the unsaturated soil are: ， ； In the formula, u θ 、v θ and w θ are the circumferential displacements of the solid phase, liquid phase and gas phase, respectively; r, z and θ represent the radial, vertical and circumferential directions in the coordinate system, respectively.

6. The torsional vibration analysis method of partially embedded piles based on unsaturated viscoelastic soil model according to claim 4 is characterized in that: The displacement boundary condition at infinity for unsaturated soil is: 。 7. The torsional vibration analysis method of partially embedded piles based on unsaturated viscoelastic soil model according to claim 4 is characterized in that: The boundary conditions of the pile top and pile bottom of the exposed and buried piles are: ， ； Where T0 represents the amplitude of the exciting torque load.

8. The torsional vibration analysis method of partially embedded piles based on unsaturated viscoelastic soil model according to claim 4 is characterized in that: The pile-soil continuity condition is: ， ， Where i represents the imaginary unit, ω represents the angular frequency, α is the fractional order, represents the elastic constant tensor element for a transversely isotropic material, and represent the model parameters of the fractional derivative viscoelastic constitutive model respectively.

9. A torsional vibration analysis device for partially buried piles based on an unsaturated viscoelastic soil model, characterized in that: include: The conditional assumption module is used to set the assumptions. The assumptions are as follows: establish a torsional vibration response model of a partially buried pile based on an unsaturated viscoelastic soil model. Assume that the soil around the pile is a transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type. The liquid and gas flows conform to the generalized Darcy law. The pile body is an elastic circular rod with zero displacement at the bottom of the pile. One part of the pile is buried in the soil and the other part is exposed on the surface. The displacement and stress of the pile-soil interface are continuous during the torsional vibration process. The pile-soil system conforms to the small deformation assumption. Only the circumferential displacement around the pile is considered. Establish a module for establishing the governing equations of the transversely isotropic unsaturated fractional derivative viscoelastic soil based on the Biot type based on the above assumptions and the three-dimensional continuum theory, and establishing the governing equations of the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface based on the Euler-Bernoulli rod; The analysis module is used to solve the control equation of the transversely isotropic unsaturated fractional derivative viscoelastic soil based on the separation of variables method, and derive the control equation of the torsional vibration of the pile body partially buried in the soil and partially exposed on the surface, obtain the complex stiffness and velocity response function of the pile top in the frequency domain, and the velocity and displacement time history curve of the pile top under the semi-sine excitation load in the time domain, so as to analyze the torsional vibration of the partially buried pile.

10. An electronic device, characterized in that: The electronic device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the torsional vibration analysis method of partially embedded piles based on an unsaturated viscoelastic soil model as described in any one of claims 1-8.

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