Large-diameter single pile foundation design method and system based on finite element simulation

Abstract

The invention belongs to the field of offshore wind power large-diameter single pile foundation design, and provides a large-diameter single pile foundation design method and system based on finite element simulation. According to the technical scheme, design parameters and corresponding geological parameters of a to-be-designed single pile foundation are determined; constructing a pile-soil finite element model according to the design parameters of the to-be-designed single pile foundation and the corresponding geological parameters; performing finite element calculation based on the pile-soil finite element model to obtain a finite element calculation result; extracting P-Y point pair data of the pile foundation based on a finite element calculation result; generating a PSI file for maritime work structure design according to the P-Y point pair data of the pile foundation; and checking the single pile foundation according to the PSI file, and if the design requirement is met, and if the requirement is not met, adjusting the design parameters of the single pile foundation until the design requirement is met. And the design precision and quality of the offshore wind power large-diameter single pile foundation are improved.

Description

Technical Field

[0001] The present invention belongs to the field of large-diameter single pile foundation design for offshore wind power, and in particular relates to a large-diameter single pile foundation design method and system based on finite element simulation. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In many offshore wind power projects, the design and construction of wind turbine foundations are the key to ensuring the stable operation of the entire wind farm. There are many forms of offshore wind power foundations. Single pile foundations have become the most widely used foundation form for offshore wind power due to their simple structure, clear force, simple construction and construction process, short construction period, and good economy. With the continuous increase in the capacity of offshore wind turbines and the continuous increase in water depth, single pile foundations have gradually developed towards larger diameters, with pile diameters reaching 6 to 10 meters, or even larger.

[0004] In the design of single piles, the traditional PY curve method recommended by the API specification is often used. This method is based on small-diameter piles in the oil and gas industry. When applied to large-diameter single pile foundations for offshore wind power, the horizontal resistance of the soil around the pile will be underestimated, and the calculated horizontal deformation of the single pile will be greater than the actual deformation, which will make the design too conservative and lead to increased construction and operating costs. The traditional PY curve method recommended by the API specification is not suitable for the design of large-diameter single pile foundations for offshore wind power. If the PY curve method is to be used in this design, the common method is to modify the traditional PY curve based on field trial pile tests or centrifuge tests, but field trial pile tests or centrifuge tests are very time-consuming and costly. Summary of the invention

[0005] In order to solve at least one technical problem existing in the above-mentioned background technology, the present invention provides a design method and system for large-diameter single pile foundation of offshore wind power based on PY curve, which proposes a PY curve calculation method based on ABAQUS finite element simulation to improve the accuracy and quality of the design of large-diameter single pile foundation of offshore wind power.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A first aspect of the present invention provides a large diameter single pile foundation design method based on finite element simulation, comprising the following steps:

[0008] Determine the design parameters of the single pile foundation to be designed and the corresponding geological parameters;

[0009] Construct a pile-soil finite element model based on the design parameters of the single pile foundation to be designed and the corresponding geological parameters;

[0010] Finite element calculation is performed based on the pile-soil finite element model to obtain finite element calculation results;

[0011] Extract PY point pair data of pile foundation based on finite element calculation results;

[0012] Generate PSI files for offshore structure design based on PY point pair data of pile foundation;

[0013] The PSI file is used to check the single pile foundation. If it meets the design requirements, the design parameters of the single pile foundation are adjusted until they meet the design requirements. If not, the design parameters of the single pile foundation are adjusted until they meet the design requirements.

[0014] Furthermore, the parameters of the single pile foundation to be designed include pile sections, pile length, wall thickness and materials; the geological parameters include soil layer distribution, soil strength, friction angle and elastic modulus.

[0015] Furthermore, before the finite element calculation of the pile-soil finite element model is performed, it includes:

[0016] The extraction interval of the PY point pairs is set, and the grid length in the length direction of the pile foundation is set according to the extraction interval of the PY point pairs; the pile foundation is divided into grids according to the grid length in the length direction of the pile foundation to obtain a pile foundation grid.

[0017] Furthermore, finite element calculation is performed based on the pile-soil finite element model to obtain finite element calculation results, including:

[0018] For each length of the pile foundation itself, the reaction force at the corresponding length is calculated by combining the normal stress and tangential stress of different nodes of each grid structure;

[0019] The horizontal displacement of the pile body at that length is calculated by combining the horizontal displacements of different nodes of each grid structure.

[0020] Furthermore, the reaction force calculation formula at each length of the pile foundation itself is:

[0021]

[0022] F n,i =σ i ′·d,

[0023] F τ,i =τ i ′·d,

[0024]

[0025]

[0026] Where F is the reaction force at each length of the pile foundation itself, F n,i is the normal reaction force at the ith node, F τ,iis the tangential reaction force at the i-th node, k is the total number of nodes on the circumference of each length of the pile foundation itself, σ i is the normal stress at node i, σ i+1 is the normal stress at node i+1, τ i is the tangential stress at node i, τ i+1 is the tangential stress at node i+1, d is the length of the grid, and θ is the angle between the current data point and the y-axis.

[0027] Furthermore, the calculation formula for the horizontal displacement of the pile foundation at each length is:

[0028]

[0029]

[0030] Among them, u y,i and u y,i+1 are the displacements of the i-th node and the i+1-th node in the y direction respectively.

[0031] Furthermore, the reaction force and horizontal displacement of the pile body at each length are the PY point pairs at that length; by traversing different time steps and the length of the pile foundation itself, a complete PY point pair is obtained.

[0032] A second aspect of the present invention provides a design system for large-diameter single pile foundation of offshore wind power based on a PY curve, comprising:

[0033] A design parameter determination module, which is used to determine the design parameters of the single pile foundation to be designed and the corresponding geological parameters;

[0034] A finite element model building module, which is used to build a pile-soil finite element model according to the design parameters of the single pile foundation to be designed and the corresponding geological parameters;

[0035] A PY point pair data extraction module is used to perform finite element calculation based on the pile-soil finite element model to obtain finite element calculation results; and extract PY point pair data of the pile foundation based on the finite element calculation results;

[0036] The pile foundation verification module is used to generate a PSI file for offshore structure design based on the PY point pair data of the pile foundation; the single pile foundation is verified against the PSI file, and if the design requirements are met, the design parameters of the single pile foundation are adjusted until the design requirements are met.

[0037] A third aspect of the present invention provides a computer-readable storage medium.

[0038] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps in the large-diameter single pile foundation design method based on finite element simulation as described above.

[0039] A fourth aspect of the present invention provides a computer device.

[0040] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps in the large-diameter single pile foundation design method based on finite element simulation as described above are implemented.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The traditional PY curve method recommended by the existing API specification is not suitable for the design of large-diameter single pile foundations for offshore wind power. The present invention constructs a pile-soil finite element model of the single pile foundation to be designed, performs finite element calculation based on the pile-soil finite element model, and obtains finite element calculation results; based on the finite element calculation results, the PY point pair data of the pile foundation is extracted, which can improve the accuracy and quality of the design of large-diameter single pile foundations for offshore wind power, help reduce the amount of engineering, reduce engineering costs, and has strong engineering feasibility.

[0043] 2. In order to solve the problem that it is time-consuming and costly to correct the traditional PY curve based on on-site trial pile tests or centrifuge tests, the present invention only needs to input the design parameters of the single pile foundation to be designed, and then the PY point pair data can be output to check the single pile foundation. If it does not meet the requirements, it can be adjusted in time, which can greatly improve the operating efficiency.

[0044] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0046] Figure 1 It is a flow chart of a design method for a large-diameter single pile foundation for offshore wind power based on a PY curve provided by an embodiment of the present invention;

[0047] Figure 2 This is a schematic diagram of a pile foundation grid provided by an embodiment of the present invention, taking a grid side length of 1 m as an example;

[0048] Figure 3 It is a schematic diagram of PY point pair calculation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0050] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0051] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0052] Explanation of terms

[0053] Calculation step: In ABAQUS, the calculation step is an important setting that divides the analysis process into different stages and is used to simulate specific loading or analysis stages and control the analysis type, time, loading parameters, and output requirements.

[0054] As mentioned in the background technology of this application, in the design of single piles, the traditional PY curve method recommended by the API specification is often used. This method is based on small-diameter piles in the oil and gas industry. When applied to large-diameter single pile foundations for offshore wind power, the horizontal resistance of the soil around the pile will be underestimated, and the calculated horizontal deformation of the single pile will be greater than the actual deformation, which will make the design too conservative and lead to increased construction and operating costs. The traditional PY curve method recommended by the API specification is not suitable for the design of large-diameter single pile foundations for offshore wind power. If the PY curve method is to be used in this design, the commonly used method is to correct the traditional PY curve based on field trial pile tests or centrifuge tests, but field trial pile tests or centrifuge tests are very time-consuming and costly.

[0055] The present invention constructs a pile-soil finite element model of a single pile foundation to be designed, performs finite element calculation based on the pile-soil finite element model, and obtains finite element calculation results; extracts PY point pair data of the pile foundation based on the finite element calculation results, thereby improving the accuracy and quality of the design of a large-diameter single pile foundation for offshore wind power, helping to reduce the amount of engineering work, reducing engineering costs, and having strong engineering feasibility. Only the design parameters of the single pile foundation to be designed need to be input, and the PY point pair data can be output to check the single pile foundation. If it does not meet the requirements, it can be adjusted in time, which can greatly improve the operating efficiency.

[0056] Embodiment 1

[0057] like Figure 1 As shown, this embodiment provides a large diameter single pile foundation design method based on finite element simulation, including the following steps:

[0058] Step 1: Determine the design parameters of the single pile foundation to be designed and the corresponding geological parameters;

[0059] In this embodiment, the parameters of the single pile foundation to be designed include pile section, pile length, wall thickness, material, etc.; geological parameters include soil layer distribution, soil strength, friction angle, elastic modulus, etc.;

[0060] Step 2: Construct a pile-soil finite element model based on the single pile foundation to be designed and geological parameters;

[0061] In this embodiment, when constructing the pile-soil finite element model, the design parameters of the single pile foundation to be designed and the corresponding geological parameters can be directly used to create the pile-soil finite element model in ABAQUS finite element software; the pile-soil finite element model can also be constructed using an existing algorithm;

[0062] Step 3: Perform finite element calculation on the constructed pile-soil finite element model to obtain finite element calculation results;

[0063] Set the interval for extracting PY point pairs, and set the grid length in the length direction of the pile foundation according to the interval for extracting PY point pairs;

[0064] Divide the pile foundation into grids according to the grid length in the length direction of the pile foundation to obtain a pile foundation grid;

[0065] In this embodiment, the pile foundation is divided into grids. When dividing, the positions of the grid nodes in the length direction of the pile foundation should be consistent with the positions of the calculated point PY pairs. If a PY point pair is taken every 1m, the grid length in the length direction of the pile foundation can be set to 1m. Figure 2 shown.

[0066] After the meshing is completed, a certain horizontal displacement condition Uy is applied to the top of the pile foundation (such as applying a y-direction displacement of 20% of the pile foundation diameter to the top of the pile foundation), and then the finite element model is submitted for calculation in ABAQUS.

[0067] After the calculation is completed, the results of the nodes at the interface are extracted in the ABAQUS post-processing interface. Specifically, for a specific calculation step and each length of the pile foundation itself, the reaction force (F, in N / m) at the length is calculated according to formulas (1)-(5);

[0068]

[0069]

[0070] F n,i =σ i ′·d (3),

[0071] F τ,i =τ i′·d (4),

[0072]

[0073] Where F is the reaction force at each length of the pile foundation itself, F n,i is the normal reaction force at the ith node, F τ,i is the tangential reaction force at the i-th node, k is the total number of nodes on the circumference of each length of the pile foundation itself, σ i is the normal stress at node i, σ i+1 is the normal stress at node i+1, τ i is the tangential stress at node i, τ i+1 is the tangential stress at node i+1, d is the length of the grid, and θ is the angle between the current data point and the y-axis.

[0074] According to formulas (6)-(7), the horizontal displacement (u) of the pile at this length is calculated. y , unit is m).

[0075]

[0076] Among them, u y,i and u y,i+1 are the displacements of the i-th node and the i+1-th node in the y direction respectively.

[0077] In this embodiment, in ABAQUS, the CPRESS (normal stress, in Pa), CSHEAR (tangential stress, in Pa), and U (displacement, in m) of each node can be quickly extracted through the built-in python command "fieldOutputs" of the software.

[0078] Step 4: Extract the PY point pair data of the pile foundation from the calculated finite element result file;

[0079] like Figure 3 As shown in the figure, node i and node i+1 are two nodes of each grid i, data point j is the center of node i and node i+1, and the reaction force and displacement at this point are extracted when extracting data. y The point pairs formed are the PY point pairs under this length. By traversing different time steps and the length of the pile foundation itself, the complete PY point pairs for pile foundation calculation can be obtained.

[0080] Step 5: Generate offshore structure design parameters based on the PY point pair data of the pile foundation;

[0081] In this embodiment, a PSI file for calculation by the offshore structure design software SACS is generated according to the PY point pairs extracted in step 4;

[0082] Step 6: Check the design parameters. If they are met, the design is completed. If not, adjust the pile foundation parameters and redesign until the design requirements are met.

[0083] Pile foundation verification: import the PSI file generated in step 5 into the SACS software to verify the single pile foundation. If the requirements are met, the design is completed; if not, adjust the pile foundation parameters and return to step 2 until the design requirements are met.

[0084] In this embodiment, steps 2-5 can be implemented in a scripted manner through the python interface provided by ABAQUS, which can greatly improve the operating efficiency.

[0085] The above scheme can improve the accuracy and quality of the design of large-diameter single pile foundations for offshore wind power, help reduce the amount of engineering work, reduce engineering costs, and have strong engineering feasibility. It can provide a basis for on-site pile tests and centrifuge tests, and contribute to the further development of pile-soil interaction research, which has important scientific research value.

[0086] Embodiment 2

[0087] This embodiment provides a large diameter single pile foundation design system based on finite element simulation, including:

[0088] A design parameter determination module, which is used to determine the design parameters of the single pile foundation to be designed and the corresponding geological parameters;

[0089] A finite element model building module, which is used to build a pile-soil finite element model according to the design parameters of the single pile foundation to be designed and the corresponding geological parameters;

[0090] A PY point pair data extraction module is used to perform finite element calculation based on the pile-soil finite element model to obtain finite element calculation results; and extract PY point pair data of the pile foundation based on the finite element calculation results;

[0091] The pile foundation verification module is used to generate a PSI file for offshore structure design based on the PY point pair data of the pile foundation; the single pile foundation is verified against the PSI file, and if the design requirements are met, the design parameters of the single pile foundation are adjusted until the design requirements are met.

[0092] Embodiment 3

[0093] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps in the large-diameter single pile foundation design method based on finite element simulation as described above are implemented.

[0094] Embodiment 4

[0095] This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps in the large-diameter single pile foundation design method based on finite element simulation as described above are implemented.

[0096] Embodiment 5

[0097] This embodiment provides a program product, which is a computer program product, including a computer program. When the computer program is executed by a processor, the steps in the large-diameter single pile foundation design method based on finite element simulation as described above are implemented.

[0098] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0099] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0100] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0101] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0102] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A large diameter single pile foundation design method based on finite element simulation, characterized in that: The steps include: Determine the design parameters of the single pile foundation to be designed and the corresponding geological parameters; Construct a pile-soil finite element model based on the design parameters of the single pile foundation to be designed and the corresponding geological parameters; Finite element calculation is performed based on the pile-soil finite element model to obtain finite element calculation results; Extract PY point pair data of pile foundation based on finite element calculation results; Generate PSI files for offshore structure design based on PY point pair data of pile foundation; The PSI file is used to check the single pile foundation. If it meets the design requirements, the design parameters of the single pile foundation are adjusted until they meet the design requirements. If not, the design parameters of the single pile foundation are adjusted until they meet the design requirements.

2. A large diameter single pile foundation design method based on finite element simulation as claimed in claim 1, characterized in that: The parameters of the single pile foundation to be designed include pile section, pile length, wall thickness and material; the geological parameters include soil layer distribution, soil strength, friction angle and elastic modulus.

3. A large diameter single pile foundation design method based on finite element simulation as claimed in claim 1, characterized in that: Before performing finite element calculation on the pile-soil finite element model, the following should be included: The extraction interval of the PY point pairs is set, and the grid length in the length direction of the pile foundation is set according to the extraction interval of the PY point pairs; the pile foundation is divided into grids according to the grid length in the length direction of the pile foundation to obtain a pile foundation grid.

4. A large diameter single pile foundation design method based on finite element simulation as claimed in claim 1, characterized in that: Finite element calculation is performed based on the pile-soil finite element model, and the finite element calculation results are obtained, including: For each length of the pile foundation itself, the reaction force at the corresponding length is calculated by combining the normal stress and tangential stress of different nodes of each grid structure; The horizontal displacement of the pile body at that length is calculated by combining the horizontal displacements of different nodes of each grid structure.

5. A large diameter single pile foundation design method based on finite element simulation as claimed in claim 4, characterized in that: The reaction force calculation formula at each length of the pile foundation itself is: F n,i =s i ′·d, F τ,i =t i ′·d, Where F is the reaction force at each length of the pile foundation itself, F n,i is the normal reaction force at the ith node, F τ,i is the tangential reaction force at the i-th node, k is the total number of nodes on the circumference of each length of the pile foundation itself, σ i is the normal stress at node i, σ i+1 is the normal stress at node i+1, τ i is the tangential stress at node i, τ i+1 is the tangential stress at node i+1, d is the length of the grid, and θ is the angle between the current data point and the y-axis.

6. A large diameter single pile foundation design method based on finite element simulation as claimed in claim 4, characterized in that: The calculation formula for the horizontal displacement of the pile foundation at each length is: Among them, u y,i and u y,i+1 are the displacements of the i-th node and the i+1-th node in the y direction respectively.

7. A large diameter single pile foundation design method based on finite element simulation as claimed in claim 1, characterized in that: The reaction force and horizontal displacement of the pile at each length are the PY point pairs at that length; by traversing different time steps and the length of the pile foundation itself, a complete PY point pair is obtained.

8. A large diameter single pile foundation design system based on finite element simulation, characterized in that: include: A design parameter determination module, which is used to determine the design parameters of the single pile foundation to be designed and the corresponding geological parameters; A finite element model building module, which is used to build a pile-soil finite element model according to the design parameters of the single pile foundation to be designed and the corresponding geological parameters; A PY point pair data extraction module is used to perform finite element calculation based on the pile-soil finite element model to obtain finite element calculation results; and extract PY point pair data of the pile foundation based on the finite element calculation results; Pile foundation verification module, which is used to generate PSI files for offshore structure design based on PY point pair data of pile foundation; The PSI file is used to check the single pile foundation. If it meets the design requirements, the design parameters of the single pile foundation are adjusted until they meet the design requirements. If not, the design parameters of the single pile foundation are adjusted until they meet the design requirements.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps in a large-diameter single pile foundation design method based on finite element simulation as described in any one of claims 1 to 7 are implemented.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps in the large-diameter single pile foundation design method based on finite element simulation as described in any one of claims 1-7 are implemented.

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