A calculation method and system for the cumulative inclination angle of offshore wind power single pile foundation

Abstract

This invention provides a method and system for calculating the cumulative inclination angle of offshore wind turbine monopile foundations. This method is applicable to the design of offshore wind turbine monopile foundations. The cumulative inclination angle consists of two components: the permanent horizontal deformation resulting from the ultimate bearing capacity load and the ultimate normal service load. By analyzing the elastic-plastic components of the total deformation, the respective cumulative inclination angles are calculated. The final cumulative inclination angle is obtained by linearly adding the two components. This calculation results in an accurate and more compliant manner with construction requirements.

Description

Technical Field

[0001] The present invention belongs to the technical field of offshore wind power monopile foundation design, and relates to a method and system for calculating the cumulative inclination angle of an offshore wind power monopile foundation. 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] The single pile foundation is currently the most widely used foundation type in offshore wind power construction, with a complete design system and clear design indicators. Regarding the control of the cumulative inclination angle at the mud surface of the single pile foundation, NB / T 10105-2018 stipulates that after the construction error of the single pile foundation is taken into account, the total cumulative inclination angle at the mud surface during the entire operation period should not exceed 0.5° (8.72‰ radians). However, the specification does not provide a specific calculation method for the cumulative inclination angle at the mud surface. In previous designs, high requirements (≤3‰ radians) were usually adopted for construction errors, while the control of the cumulative inclination angle at the foundation mud surface was ignored. Summary of the Invention

[0004] To address these issues, this paper proposes a method and system for calculating the cumulative inclination angle of offshore wind turbine monopile foundations. This method, applied to the design of offshore wind turbine monopile foundations, uses two components: the permanent horizontal deformation resulting from the ultimate bearing capacity load and the ultimate service load. By analyzing the elastic-plastic components of the total deformation, the respective cumulative inclination angles are calculated. The final cumulative inclination angle is then linearly added together, resulting in an accurate calculation that better meets construction requirements.

[0005] According to some embodiments, the present invention adopts the following technical solutions:

[0006] A method for calculating the cumulative inclination angle of an offshore wind power monopile foundation comprises the following steps:

[0007] The corresponding cumulative inclination angle is obtained by converting the permanent horizontal deformation caused by the bearing capacity ultimate load and the normal service ultimate load respectively;

[0008] The respective cumulative inclination angles are calculated by analyzing the elastic-plastic components in the total deformation, and the final cumulative inclination angle is obtained by linearly adding the two.

[0009] As an optional implementation, the specific process of converting the permanent horizontal deformation generated by the bearing capacity limit load into the cumulative inclination angle includes:

[0010] Determine external loads;

[0011] Based on the variable load, calculate the ultimate load of bearing capacity;

[0012] Simulating the interaction between the single pile and the soil, gradually applying the ultimate load in proportion, calculating the deformation of the mud surface of the single pile foundation under different loading proportions, and drawing a first deformation curve;

[0013] Based on the deformation, calculating the deformation of the mud surface of the single pile foundation under different loading ratios, and drawing a second deformation curve;

[0014] According to the loading path of the second deformation curve, the unloading path of the first deformation curve is obtained, the total deformation and elastic deformation are calculated, and then the irreversible plastic deformation is obtained;

[0015] The inclination angle under this load condition is calculated based on the irreversible plastic deformation and the distance from the rotation fixing point of the single pile foundation to the mud surface.

[0016] As a further limited embodiment, the external load includes the deadweight of the monopile foundation and its accessory structures, the weight of the equipment, the extreme load of the wind turbine, the wave load and the ocean current load.

[0017] As an optional implementation, the specific process of converting the permanent horizontal deformation generated by the normal service limit load into the cumulative inclination angle includes:

[0018] Determine external loads;

[0019] Based on the variable load, the bearing capacity limit load is calculated to obtain the normal use limit load, the limit load is gradually applied in proportion, the deformation of the mud surface of the single pile foundation under different loading proportions is calculated, and a first deformation curve is drawn;

[0020] Based on the deformation, calculating the deformation of the mud surface of the single pile foundation under different loading ratios, and drawing a second deformation curve;

[0021] According to the loading path of the second deformation curve, the unloading path of the first deformation curve is obtained, the total deformation and elastic deformation are calculated, and then the irreversible plastic deformation is obtained;

[0022] The inclination angle under this load condition is calculated based on the irreversible plastic deformation and the distance from the rotation fixing point of the single pile foundation to the mud surface.

[0023] As a further limited implementation method, the external load includes the deadweight of the single pile foundation and its auxiliary structures, the weight of the equipment, the normal power generation load of the wind turbine, wave load and current load.

[0024] As an alternative embodiment, the process of calculating the bearing capacity limit load is based on the sum of all variable loads in the external loads.

[0025] As an optional implementation, the specific process of gradually applying the ultimate load in proportion is to increase the load from 0% to more than 100% at intervals of a set percentage.

[0026] As an optional implementation method, the specific process of drawing the second deformation curve includes: in the initial stage of loading, the soil deformation is in the elastic range, taking the first several data of the first deformation curve, performing a proportional linear fit to simulate the elastic stage of soil deformation, extending it to obtain the deformation of the single pile foundation mud surface under different loading ratios in the elastic stage, and drawing the second deformation curve.

[0027] As an optional implementation, the specific process of calculating the total deformation and elastic deformation includes: obtaining the unloading path of the first deformation curve according to the loading path of the second deformation curve from 0 to 100%, and obtaining the total deformation and elastic deformation according to the positions of the first deformation curve and the second deformation curve at the loading ratio of 100%. The irreversible plastic deformation is the difference between the total deformation and the elastic deformation.

[0028] As an optional implementation, the rotation fixing point of the single pile foundation is the intersection of the pile deformation curve and the vertical line when the loading ratio is 100%.

[0029] A system for calculating the cumulative inclination angle of an offshore wind power monopile foundation, comprising:

[0030] The first calculation module is configured to calculate the permanent horizontal deformation generated by the bearing capacity limit load and obtain the corresponding cumulative inclination angle;

[0031] The second calculation module is configured to calculate the permanent horizontal deformation generated by the normal service limit load and convert it into a corresponding cumulative inclination angle;

[0032] The analysis and calculation module is configured to calculate the respective cumulative inclination angles by analyzing the elastic-plastic components in the total deformation, and linearly add the two to obtain the final cumulative inclination angle.

[0033] A terminal device includes a processor and a computer-readable storage medium, wherein the processor is used to implement various instructions; the computer-readable storage medium is used to store multiple instructions, and the instructions are suitable for being loaded by the processor and executing the steps in the described method.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention can calculate the cumulative inclination value at the mud surface of a single pile foundation. Under the premise of a given construction error, a quantitative design limit value can be given for the single pile foundation design to ensure that the sum of the two does not exceed 0.5°.

[0036] In large-capacity units and deep-water conditions, the inclination angle of a single pile foundation is generally large, and the cumulative inclination angle at the mud surface even becomes a controlling working condition. The method provided by the present invention can be used to carry out a refined design of the single pile foundation, which is beneficial to the control of the single pile foundation engineering quantity. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, 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.

[0038] Figure 1 Schematic diagram of each curve and deformation under different loading ratios;

[0039] Figure 2 It is a schematic diagram of the pile deformation curve;

[0040] Figure 3 It is a flowchart of an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0043] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0044] A calculation method for the cumulative inclination angle of offshore wind power single pile foundation, such as Figure 3 As shown, the following steps are included:

[0045] (1) Determine the basic external loads, including the deadweight of the single pile foundation and its ancillary structures, equipment weight, extreme loads on the wind turbine, normal power generation loads on the wind turbine, wave loads, and current loads. The wind turbine-related loads should meet the requirements of the IEC specifications. The wave height and period, and current velocity should be determined based on a 50-year return period, and the wave and current loads should be calculated using the classic Morrison formula.

[0046] (2) Simulate the interaction between a single pile and the soil. The relationship between the lateral resistance and deformation of the soil is calculated using the py curve method under cyclic loading conditions specified in the API specification. The single pile foundation is simplified to a multi-node continuous beam model. The number of nodes should ensure the accuracy of the analysis. The relationship between the lateral resistance and deformation of the soil is applied at the nodes in the form of nonlinear springs.

[0047] (3) Calculate the ultimate load of bearing capacity, which is the combination of the basic loads in step (1) and is calculated as follows:

[0048]

[0049] Where:

[0050] G ik ——The standard value of the i-th permanent load, which is the deadweight of the structure and the weight of the equipment;

[0051] Q 1k - The standard value of the first variable acting load is the maximum of the wind turbine extreme load, wave load, current load and other variable loads;

[0052] Q jk ——The standard value of the jth variable acting load, which is the value divided by Q 1k Other variable loads;

[0053] ψ cj ——The combination coefficient of the jth variable action is taken as 0.7.

[0054] (4) Apply the limit load obtained in step (3) proportionally, at intervals of 10% (ΔS d =10%×S d ), increasing from 0% to more than 100%. At this time, part of the soil deformation has entered the plastic stage. The deformation of the single pile foundation mud surface under different loading ratios is calculated and plotted as curve C1. Figure 1 .

[0055] (5) In the initial stage of loading, the soil deformation is in the elastic range. Therefore, the first four data points of curve C1 are used to make a proportional linear fit (y = kx) to simulate the elastic stage of soil deformation. The deformation of the single pile foundation mud surface under different loading ratios in the elastic stage is obtained by extending it and plotting it into curve C2. Figure 1 .

[0056] (6) According to the loading path of curve C2 from 0 to 100%, the unloading path of curve C1 is obtained, that is, curve C3, see Figure 1 According to the position of curves C1 and C2 when the loading ratio is 100%, the total deformation y is obtained. tot and elastic deformation y el, and the irreversible plastic deformation y pl :

[0057] y pl =y tot -y el

[0058] (7) When the loading ratio is 100%, the intersection of the pile deformation curve C4 and the vertical line is the rotation fixed point P, see Figure 2 According to the plastic deformation y pl The distance d from the rotation fixed point P of the single pile foundation to the mud surface is used to calculate the inclination angle α under this load condition. u :

[0059] α u =tan -1 (y pl / d)

[0060] (8) Replace the extreme load of the wind turbine in the variable load of step (3) with the normal power generation load, and keep the rest unchanged to obtain the normal use limit load, and repeat steps (4) to (7) to obtain the inclination angle α at the mud surface under the normal use limit load. s ;

[0061] (9) α u and α s The cumulative inclination angle at the foundation mud surface is obtained by linear accumulation:

[0062] α t =α u +α s

[0063] The present invention also provides the following product embodiments:

[0064] A system for calculating the cumulative inclination angle of an offshore wind power monopile foundation, comprising:

[0065] The first calculation module is configured to calculate the permanent horizontal deformation generated by the bearing capacity limit load and obtain the corresponding cumulative inclination angle;

[0066] The second calculation module is configured to calculate the permanent horizontal deformation generated by the normal service limit load and convert it into a corresponding cumulative inclination angle;

[0067] The analysis and calculation module is configured to calculate the respective cumulative inclination angles by analyzing the elastic-plastic components in the total deformation, and linearly add the two to obtain the final cumulative inclination angle.

[0068] A terminal device includes a processor and a computer-readable storage medium, wherein the processor is used to implement various instructions; the computer-readable storage medium is used to store multiple instructions, and the instructions are suitable for being loaded by the processor and executing the steps in the described method.

[0069] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment 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 magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0070] 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 flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, 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 flowcharts and / or block diagrams. 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.

[0071] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work 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 The function specified in one or more boxes.

[0072] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0073] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

[0074] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A method for calculating the cumulative inclination angle of an offshore wind power single pile foundation, characterized by: The following steps are involved: The corresponding cumulative inclination angle is obtained by converting the permanent horizontal deformation caused by the bearing capacity ultimate load and the normal service ultimate load respectively; By analyzing the elastic-plastic components in the total deformation, the respective cumulative inclination angles are calculated, and the final cumulative inclination angle is obtained by linearly adding the two. The specific process of converting the permanent horizontal deformation generated by the ultimate load of bearing capacity into the cumulative inclination angle includes: Determine external loads; Based on the variable load, calculate the ultimate load of bearing capacity; Simulating the interaction between the single pile and the soil, gradually applying the ultimate load in proportion, calculating the deformation of the mud surface of the single pile foundation under different loading proportions, and drawing a first deformation curve; Based on the deformation, calculating the deformation of the mud surface of the single pile foundation under different loading ratios, and drawing a second deformation curve; According to the loading path of the second deformation curve, the unloading path of the first deformation curve is obtained, the total deformation and elastic deformation are calculated, and then the irreversible plastic deformation is obtained; Calculate the inclination angle under this load condition based on the irreversible plastic deformation and the distance from the rotation fixing point of the single pile foundation to the mud surface; The calculation formula for calculating the ultimate load of bearing capacity is: Where: For the The standard value of the permanent load is the deadweight of the structure and the weight of the equipment; is the standard value of the first variable acting load, which is the maximum of the wind turbine extreme load, wave load, current load and other variable loads; For the The standard value of the variable acting load is Other variable loads; For the The combined coefficient of the variable effects.

2. The method for calculating the cumulative inclination angle of an offshore wind power monopile foundation according to claim 1, wherein: The external loads include the deadweight of the single pile foundation and its ancillary structures, the weight of the equipment, the extreme load of the wind turbine, wave loads and current loads.

3. The method for calculating the cumulative inclination angle of an offshore wind power monopile foundation according to claim 1, wherein: The specific process of converting the permanent horizontal deformation caused by the normal service limit load into the cumulative inclination angle includes: Determine external loads; Based on the variable load, a normal service limit load is calculated to obtain the normal service limit load, the limit load is gradually applied in proportion, the deformation of the mud surface of the single pile foundation under different loading proportions is calculated, and a first deformation curve is drawn; Based on the deformation, calculating the deformation of the mud surface of the single pile foundation under different loading ratios, and drawing a second deformation curve; According to the loading path of the second deformation curve, the unloading path of the first deformation curve is obtained, the total deformation and elastic deformation are calculated, and then the irreversible plastic deformation is obtained; The inclination angle under this load condition is calculated based on the irreversible plastic deformation and the distance from the rotation fixing point of the single pile foundation to the mud surface.

4. The method for calculating the cumulative inclination angle of an offshore wind power monopile foundation according to claim 3, wherein: The external loads include the deadweight of the single pile foundation and its ancillary structures, the weight of the equipment, the normal power generation load of the wind turbine, wave loads and current loads.

5. A method for calculating the cumulative inclination angle of an offshore wind turbine monopile foundation according to any one of claims 1 to 4, characterized in that: The specific process of gradually applying the ultimate load in proportion is to increase the load from 0% to more than 100% at intervals of a set percentage.

6. A method for calculating the cumulative inclination angle of an offshore wind turbine monopile foundation according to any one of claims 1 to 4, characterized in that: The specific process of drawing the second deformation curve includes: in the initial stage of loading, the soil deformation is in the elastic range, taking the first several data of the first deformation curve, performing a proportional linear fit to simulate the elastic stage of soil deformation, extending it to obtain the deformation of the single pile foundation mud surface under different loading ratios in the elastic stage, and drawing the second deformation curve.

7. A method for calculating the cumulative inclination angle of an offshore wind turbine monopile foundation according to any one of claims 1 to 4, characterized in that: The specific process of calculating the total deformation and elastic deformation includes: obtaining the unloading path of the first deformation curve based on the loading path of the second deformation curve from 0 to 100%, and obtaining the total deformation and elastic deformation based on the positions of the first deformation curve and the second deformation curve at the loading ratio of 100%. The irreversible plastic deformation is the difference between the total deformation and the elastic deformation. Alternatively, the rotation fixing point of the single pile foundation is the intersection of the pile deformation curve and the vertical line when the loading ratio is 100%.

8. A calculation system for the cumulative inclination angle of an offshore wind power single pile foundation, characterized by: include: The first calculation module is configured to calculate the permanent horizontal deformation generated by the bearing capacity limit load and obtain the corresponding cumulative inclination angle; The second calculation module is configured to calculate the permanent horizontal deformation generated by the normal service limit load and obtain the corresponding cumulative inclination angle; The analysis and calculation module is configured to calculate the respective cumulative inclination angles by analyzing the elastic-plastic components in the total deformation, and linearly add the two to obtain the final cumulative inclination angle; The specific process of converting the permanent horizontal deformation generated by the ultimate load of bearing capacity into the cumulative inclination angle includes: Determine external loads; Based on the variable load, calculate the ultimate load of bearing capacity; Simulating the interaction between the single pile and the soil, gradually applying the ultimate load in proportion, calculating the deformation of the mud surface of the single pile foundation under different loading proportions, and drawing a first deformation curve; Based on the deformation, calculating the deformation of the mud surface of the single pile foundation under different loading ratios, and drawing a second deformation curve; According to the loading path of the second deformation curve, the unloading path of the first deformation curve is obtained, the total deformation and elastic deformation are calculated, and then the irreversible plastic deformation is obtained; Calculate the inclination angle under this load condition based on the irreversible plastic deformation and the distance from the rotation fixing point of the single pile foundation to the mud surface; The calculation formula for calculating the ultimate load of bearing capacity is: Where: For the The standard value of the permanent load is the deadweight of the structure and the weight of the equipment; is the standard value of the first variable acting load, which is the maximum of the wind turbine extreme load, wave load, current load and other variable loads; For the The standard value of the variable acting load is Other variable loads; For the The combined coefficient of the variable effects.

9. A terminal device, characterized in that: The method comprises a processor and a computer-readable storage medium, wherein the processor is used to implement various instructions; and the computer-readable storage medium is used to store a plurality of instructions, wherein the instructions are suitable for being loaded by the processor and executing the steps in the method according to any one of claims 1 to 7.

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