A method for calculating the bearing capacity of a fan foundation on collapsible soil
By analyzing the settlement data and soil quality characteristics of the test points, combined with the distribution of extruded piles, the bearing capacity weight is given, and the deviation problem of the foundation bearing capacity calculation of the wetted foundation fan in the existing technology is solved, and the calculation accuracy and engineering are improved. quality.
Patent Information
- Application Number
- CN202411252593.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2044-09-09
AI Technical Summary
When calculating the bearing capacity of the wet foundation fan, the existing technology failed to effectively consider the differences in soil quality characteristics between different test points and the distribution of tight piles, resulting in a large deviation from the actual bearing capacity, which affected the project quality. .
By obtaining the settlement amount of each test point under different pressures, analyzing the changes in linear and nonlinear stages, determining the difference in compaction and soil compactness, combining the difference in the number of squeezed piles and the pressure characteristic value, each test point is given a specific value. weighted fusion to correct the basic bearing capacity.
The accuracy of the calculation of the foundation bearing capacity of the wet-sinking foundation fan is improved, and the overall bearing capacity of the foundation is pulled up due to the good bearing effect of a single test point is avoided, and the bearing capacity of the fan foundation is more accurately reflected.
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Abstract
Description
Technical Field
[0001] The present application relates to the technical field of foundation bearing capacity calculation, and in particular to a method for calculating the bearing capacity of a wind turbine foundation on a collapsible foundation. Background Art
[0002] Collapsible geology is a special type of soil, characterized by uniform soil quality but loose structure. When it is not soaked, the soil has low compressibility and relatively high strength. However, after being soaked by water of a certain pressure, the soil structure is destroyed, causing the soil to sink significantly and its strength to be greatly reduced. Since the overall mass of the wind turbine is large, the collapsible foundation needs to be further processed when it is installed on collapsible land. In the current construction process, the down-hole dynamic compaction method (DDC) is often used to compact the foundation with compacted piles to obtain a composite foundation. The foundation bearing capacity calculation needs to be performed for the compacted composite foundation to ensure that it meets the wind turbine installation specifications.
[0003] The existing technology generally uses a flat plate load test to obtain a load-settlement curve, and uses the curve to obtain the basic bearing capacity of the wind turbine foundation. However, in the calculation process, the same weight is given to each test point, and it is usually not taken into account that the base plane of the wind turbine is large, the soil properties between different test points are different, and there are differences in the distribution of compaction piles around different test points, which leads to deviations in the load-settlement curves of different test points, resulting in a large deviation between the estimated foundation bearing capacity and the actual foundation bearing capacity, affecting the engineering quality of the wind turbine installation. Summary of the invention
[0004] In view of the above, it is necessary to provide a method for calculating the bearing capacity of a fan foundation on collapsible soil, which improves the accuracy of calculating the bearing capacity of a fan foundation on collapsible soil compared with the traditional method for calculating the bearing capacity of a fan foundation on collapsible soil.
[0005] A method for calculating the bearing capacity of a wind turbine foundation on collapsible ground in this application adopts the following technical solution:
[0006] An embodiment of the present application provides a method for calculating the bearing capacity of a wind turbine foundation on collapsible ground, the method comprising the following steps:
[0007] Obtain the settlement of each test point on the wind turbine foundation at each pressure value;
[0008] Each pressure value and the corresponding settlement amount are combined into a two-dimensional settlement data point, and the inflection point in the settlement data point of each test point is obtained. The settlement data point of each test point is divided into two parts: a linear stage and a nonlinear stage, and the pressure value of the inflection point is used as the pressure characteristic value of each test point;
[0009] Comprehensively analyze the linear changes of settlement data points in the linear stage of each test point, as well as the distribution of settlement data points in the nonlinear stage, to determine the data stability of each test point;
[0010] Based on the change trend of all settlement data points in the linear stage of each test point and the change trend of two adjacent settlement data points, the data tilt degree of each test point is determined;
[0011] The compaction degree of each test point is obtained by combining the data stability and data inclination of each test point;
[0012] Determine the soil compaction distinction value of any test point based on the number of compaction piles within the neighborhood of any test point and the difference in pressure characteristic values between any test point and all test points within its neighborhood;
[0013] Based on the compaction degree and soil density differentiation value of all test points, the bearing capacity weight of each test point is determined;
[0014] The ultimate bearing capacity of each test point is obtained, and the comprehensive foundation bearing capacity of the wind turbine foundation is determined by combining the pressure characteristic value and the bearing capacity weight, and the comprehensive foundation bearing capacity is corrected to obtain the foundation bearing capacity of the wind turbine foundation.
[0015] In one embodiment, the data stability is calculated as follows:
[0016] ; In the formula, Indicates the data stability of the t-th test point; Indicates the goodness of fit of the settlement data points in the nonlinear stage of the t-th test point; represents the number of settlement data points in the linear stage of the t-th test point; represents the pressure value of the ith settlement data point in the linear stage of the tth test point; obtains the fitting straight line of all settlement data points in the linear stage of the tth test point, It represents the pressure value corresponding to the settlement amount of the ith settlement data point in the linear stage of the tth test point on the fitting straight line.
[0017] In one embodiment, the expression of the data skew degree is:
[0018] ; In the formula, Indicates the degree of data skewness at the t-th test point; represents the slope of the fitted straight line at the t-th test point; It represents the mean of the slopes of the straight lines determined by all two adjacent settlement data points in the linear stage of the tth test point.
[0019] In one embodiment, the compaction degree is the ratio of the data stability degree to the data inclination degree of each test point.
[0020] In one embodiment, the process of determining the soil density distinction value is as follows:
[0021] Calculate the difference in pressure characteristic values between any test point and each test point in its neighborhood except itself, and record it as pressure characteristic difference;
[0022] Calculate the mean of all the pressure characteristic differences at any test point, and record it as the difference mean;
[0023] The fusion result of the number of the compacted piles and the difference mean is used as the soil density distinction value of any test point.
[0024] In one embodiment, the soil compaction distinction value is the product of the number of the compaction piles and the mean value of the difference.
[0025] In one embodiment, the process of determining the bearing capacity weight is:
[0026] Calculate the sum of the compaction degree and soil density difference value of each test point;
[0027] Calculate the cumulative sum of the reciprocals of the sum values of all test points;
[0028] Based on the cumulative sum and the sum value of each test point, the bearing capacity weight of each test point is obtained.
[0029] In one embodiment, the bearing capacity weight is the ratio of the cumulative sum to the sum of each test point.
[0030] In one embodiment, the process of determining the comprehensive foundation bearing capacity is:
[0031] Based on the magnitude relationship between the ultimate bearing capacity and the pressure characteristic value of each test point, the bearing capacity characteristic value of each test point is determined;
[0032] The product of the bearing capacity characteristic value and the bearing capacity weight of each test point is calculated and recorded as the weighted product, and the accumulated value of the weighted product of all test points is taken as the comprehensive foundation bearing capacity of the wind turbine foundation.
[0033] This application has at least the following beneficial effects:
[0034] In summary, this application determines the compaction degree of each test point by analyzing the change of the settlement data points in the linear stage of each test point, the size of the change trend, and the distribution of the settlement data points in the nonlinear stage, reflecting the compaction of the foundation at each test point; combined with the difference in the pressure characteristic value between each test point and the remaining test points in the neighborhood, and the number of compaction piles in the neighborhood of each test point, the soil density distinction value of each test point is determined to reflect the difference in the compaction of the foundation between each test point and the remaining test points in the neighborhood;
[0035] Furthermore, based on the compaction degree and soil density distinction value of all test points, the bearing capacity weight of each test point is determined, the bearing capacity characteristic values of all test points are weightedly fused, and the fusion result is corrected to obtain the basic bearing capacity of the wind turbine foundation. Compared with the traditional method of obtaining the basic bearing capacity of the foundation by the averaging method, the present application takes into account the differences in soil properties between different test points and the differences in the distribution of compaction piles around different test points. Using a specific bearing capacity weight for each test point can better integrate the bearing capacity of each test point on the wind turbine foundation, avoid the situation where the overall bearing capacity of the foundation is increased due to the better bearing effect of a single test point, and improve the accuracy of calculating the bearing capacity of the foundation of a wind turbine on a collapsible foundation. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0037] Figure 1 A flowchart of the steps of a method for calculating the bearing capacity of a wind turbine foundation on collapsible ground provided in this application;
[0038] Figure 2 This is a schematic diagram of the distribution of compaction piles and test points on the wind turbine foundation;
[0039] Figure 3 A schematic diagram of the process of determining the soil density zone value;
[0040] Figure 4 Schematic diagram of the process of determining the bearing capacity weight. DETAILED DESCRIPTION
[0041] In the description of the embodiments of the present application, words such as "exemplary", "or", "for example" and the like are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "or", "for example" and the like is intended to present related concepts in a concrete manner.
[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the present application. The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. It should be understood that, unless otherwise specified, " / " means or.
[0043] It should also be noted that the terms "first" and "second" in the present application are used to distinguish similar objects rather than to describe a specific order or sequence.
[0044] The specific scheme of the method for calculating the bearing capacity of a wind turbine foundation on collapsible soil provided by the present application is described in detail below with reference to the accompanying drawings.
[0045] An embodiment of the present application provides a method for calculating the bearing capacity of a wind turbine foundation on a collapsible foundation. Specifically, the following method for calculating the bearing capacity of a wind turbine foundation on a collapsible foundation is provided. Figure 1 , the method comprises the following steps:
[0046] Step 1: Obtain the settlement of each test point on the wind turbine foundation at each pressure value.
[0047] When installing wind turbines in collapsible areas, in order to eliminate the collapsible nature of the collapsible soil and improve its bearing characteristics, this embodiment uses the deep layer compaction method in the hole, specifically:
[0048] According to the entire wind turbine foundation area, the compaction pile spacing and pile length are designed. In the construction scenario of this embodiment, the compaction pile spacing is set to 5m and the pile length is 15m. First, a long spiral excavator is used to drill a hole with a diameter of 1.5m. The hole is backfilled with soil and compacted step by step with a compactor. Layered compaction is selected, and the volume of each layer of backfilled soil is 6m 3 The mass of the rammer is 20t, the height of each lift is 10m, and each layer is rammed 12 times. The distribution diagram of compaction piles and test points on the wind turbine foundation is shown in the figure. Figure 2As shown in the figure, a represents the circular foundation of the wind turbine installed on the collapsible soil, b represents the deep compaction pile in the hole, and c represents the flat plate load test point. Among them, the values of the compaction pile spacing, pile length, hole diameter, volume of each layer of backfill soil, rammer weight, height of each lift and number of ramming times for each layer are all preset by humans and can be set by the implementer. This application does not impose any special restrictions.
[0049] After compacting the collapsible foundation, a composite foundation is obtained, and a load test is carried out between the compaction piles. The test points are selected by randomly selecting W points on the wind turbine foundation for the test. It should be noted that the test points are not on the compaction piles.
[0050] In this embodiment, the value of W is 10. The value of W is preset manually and can be set by the implementer. This application does not impose any special restrictions.
[0051] The load test details are implemented in accordance with the Code for Design of Building Foundations (GB50007-2011). In this embodiment, the pressure plate is set to be circular and the area of the pressure plate is 0.5m 2 The applied load is graded into 20 levels, and the maximum load is three times the mass of the wind turbine equipment. The area of the pressure plate, the applied load grade and the maximum load are preset manually and can be set by the implementer. This application does not impose any special restrictions.
[0052] Step 2: Calculate the compaction degree of each test point based on the settlement of each test point under all pressure values.
[0053] When conducting a load test on a single test point, a pressure plate is placed on the composite foundation obtained by compacting the collapsible soil with compaction piles, and a linearly increasing pressure is applied to the pressure plate at equal time intervals to observe the deformation of the composite foundation soil. Ideally, the composite foundation will undergo overall shear failure, that is, as the pressure increases, the indentation of the foundation will gradually increase, and the soil on both sides of the pressure plate will bulge. When the pressure is further increased, the sliding amount of the soil on both sides will gradually increase. When the pressure exceeds the ultimate bearing capacity of the composite foundation, the foundation will lose its bearing capacity, and the soil will undergo shear failure.
[0054] Step 2.1, each pressure value and the corresponding settlement amount are combined into two-dimensional settlement data points, the inflection point in the settlement data points of each test point is obtained, and the settlement data points of each test point are divided into two parts: linear stage and nonlinear stage, and the pressure value of the inflection point is used as the pressure characteristic value of each test point.
[0055] Based on the above analysis, the load-settlement curve of a single test point can be divided into three stages under ideal conditions. The first stage is the elastic deformation stage of the soil, in which the settlement increases linearly with the pressure value; the second stage is the plastic deformation stage, in which part of the strength of the land is lost, and the settlement increases rapidly with the increase of the pressure value; the third stage is the steep drop stage, at which time the foundation loses its bearing capacity and the land will suddenly deform.
[0056] Due to the large area of the wind turbine foundation, the types and thickness of collapsible soils may vary between different test points. The soil types include Malan loess, paleosol, Lishi loess, etc., which results in different compaction degrees at each test point on the composite foundation after compaction by compaction piles, that is, different load-settlement curves at each test point. In order to measure the compaction of a single test point, it is necessary to analyze the settlement of the test point.
[0057] Each pressure value and the corresponding settlement amount are combined into two-dimensional settlement data points. The higher the compaction degree of a single test point, the more likely it is that there are two manifestations: First, the more stable the linear change of the data point is. By compacting the foundation with compaction piles, the cohesion between the underground soil can be enhanced, so the fluctuation of the actual settlement amount in the elastic deformation stage of the soil is smaller and more stable. Second, the lower the inclination of the data point, the smaller the settlement of the test point in the elastic deformation stage of the soil when the same pressure is applied, that is, the lower the inclination of the settlement data point in the elastic deformation stage of the soil, the higher the compaction degree of the test point.
[0058] In order to measure the fluctuation of data in the elastic deformation stage of the soil, the Kneed package in Python language is used to obtain the inflection point in the settlement data points of each test point, and the pressure value of the inflection point is used as the pressure characteristic value of each test point, and all the settlement data points before the inflection point of each test point are used as the linear stage, and all the settlement data points after the inflection point of each test point are used as the nonlinear stage. The linear stage is the elastic deformation stage of the soil, and the nonlinear stage includes the plastic deformation stage and the steep drop stage. The Kneed method for detecting inflection points is a well-known technology, and this application will not repeat it.
[0059] Step 2.2, comprehensively analyze the linear changes of the settlement data points in the linear stage of each test point, and the distribution of the settlement data points in the nonlinear stage, to determine the data stability of each test point.
[0060] Based on the above analysis, firstly, the data stability of each test point is determined by combining the linear change of the settlement data points in the linear stage of each test point and the distribution of the settlement data points in the nonlinear stage. The expression is:
[0061] ; In the formula, represents the data stability of the t-th test point; obtains the fitting curve of all the settlement data points in the nonlinear stage of the t-th test point, and calculates the fitting goodness of the settlement data points in the nonlinear stage of the t-th test point according to the fitting curve, Indicates the goodness of fit of the settlement data points in the nonlinear stage of the t-th test point; represents the number of settlement data points in the linear stage of the t-th test point; represents the pressure value of the ith settlement data point in the linear stage of the tth test point; obtains the fitting straight line of all settlement data points in the linear stage of the tth test point, It represents the pressure value corresponding to the settlement amount of the ith settlement data point in the linear stage of the tth test point on the fitting straight line.
[0062] In this embodiment, the goodness of fit is R-squared. As other implementation methods, based on the measurable degree of fit of the settlement data points in the nonlinear stage, the implementer may use other methods to calculate the goodness of fit, such as mean square error, root mean square error, etc., and this application does not impose any special restrictions.
[0063] In this embodiment, the least squares straight line fitting method is used to obtain the fitting straight line. As other implementation methods, on the basis of obtaining the fitting straight line of the settlement data points, the implementer can use other existing technologies to obtain the fitting straight line, such as linear regression analysis, weighted least squares method, etc., and this application does not make any special restrictions.
[0064] It should be noted that: if the overall compaction condition of the t-th test point is better, the settlement data points in the elastic deformation stage of the soil in the settlement load test basically present a linear distribution, so that the difference between the actual pressure value and the fitted pressure value is smaller; at the same time, the greater the goodness of fit, the more reasonable the division of the linear stage and the nonlinear stage, and the more reliable the overall compaction condition of the test point based on the linear stage analysis divided at this time, the greater the value of the data stability of the t-th test point.
[0065] Step 2.3, based on the change trend of all settlement data points in the linear stage of each test point and the change trend of two adjacent settlement data points, determine the data tilt degree of each test point.
[0066] Furthermore, in order to measure the inclination degree of the settlement data points in the elastic deformation stage of the soil at each test point, the data inclination degree of each test point is determined based on the change trend of all settlement data points in the linear stage of each test point and the change trend of two adjacent settlement data points. The expression is:
[0067] ; In the formula, Indicates the degree of data skewness at the t-th test point; represents the slope of the fitted straight line at the t-th test point; It represents the mean of the slopes of the straight lines determined by all two adjacent settlement data points in the linear stage of the tth test point.
[0068] It should be noted that: if the compaction condition of the t-th test point is better, the settlement of the test point in the elastic deformation stage of the soil will be smaller when the same pressure is applied, so that the inclination of the settlement data points in the elastic deformation stage of the soil will be smaller. Therefore, the slope of the fitting straight line of all settlement data points in the linear stage of the t-th test point will be smaller, and the mean value of the slope of the straight line determined by all two adjacent settlement data points in the linear stage will also be smaller, thereby obtaining a smaller value of the data inclination of the test point.
[0069] Step 2.4, combining the data stability and data inclination of each test point to obtain the compaction degree of each test point.
[0070] The expression of compaction degree of each test point is:
[0071] ; In the formula, Indicates the compaction degree of the tth test point; Indicates the data stability of the t-th test point; Indicates the degree of data skewness at the tth test point.
[0072] It should be noted that: if the foundation compaction condition of the t-th test point is worse, the soil structure is more likely to change rapidly under the action of load, resulting in the settlement behavior not conforming to the typical linear and nonlinear stages. At this time, the linear change degree of the settlement data points in the linear stage is smaller, making the value of the data stability smaller; at the same time, when the same pressure is applied, the settlement of the t-th test point in the linear stage is greater. Therefore, the greater the inclination of the settlement data points in the linear stage obtained by the inflection point, the greater the value of the data inclination, and the smaller the compaction value of the t-th test point.
[0073] Step 3: Determine the soil compaction distinction value of any test point based on the number of compaction piles within the neighborhood of any test point and the difference in pressure characteristic values between the test point and all test points within its neighborhood.
[0074] The compaction degree of a single test point can reflect the compaction of the foundation at that test point. However, in reality, the foundation area of the wind turbine is relatively large, and the compaction of a single test point is not only related to the underground soil conditions, but also to the distribution of compaction piles around the test point. If there are more compaction piles around a single test point, the soil compaction of the test point is better. Therefore, further analysis is required based on the distribution of compaction piles around the test point.
[0075] With each test point as the center, a circle with a radius of r is set, which may contain multiple compaction piles and multiple test points. The area within the circle with each test point as the center is taken as the neighborhood range of each test point.
[0076] In this embodiment, the value of r is 7m. The value of r is preset manually and can be set by the implementer. This application does not impose any special restrictions.
[0077] If there are more compaction piles around a single test point, the soil around the test point will be denser after being squeezed by the compaction piles. Therefore, the pressure characteristic value of the test point is greater than the pressure characteristic value of the test points within the neighborhood.
[0078] Based on the above analysis, the soil compaction distinction value of any test point is determined based on the number of compaction piles in the neighborhood of any test point and the difference in pressure characteristic values between any test point and all test points in its neighborhood. The expression is:
[0079] ; In the formula, It represents the soil density distinction value of the t-th test point; represents the number of compaction piles in the neighborhood of the t-th test point; Represents the number of test points in the neighborhood of the t-th test point except itself; represents the pressure characteristic value of the tth test point; Represents the pressure characteristic value of the jth test point in the neighborhood of the tth test point excluding itself.
[0080] It should be noted that: if the number of compaction piles around the t-th test point is greater, and the difference in pressure characteristic values between the t-th test point and its surrounding test points is greater, it means that the soil at the t-th test point is more compacted, and the soil density distinction value of the test point is greater; the greater the soil density distinction value, the greater the difference in foundation compaction between the t-th test point and the rest of the test points in the neighborhood. The flow chart for determining the soil density distinction value is as follows: Figure 3 shown.
[0081] Step 4: Determine the bearing capacity weight of each test point based on the compaction degree and soil density differentiation value of all test points.
[0082] Since the wind turbine foundation area contains multiple test points, in order to avoid the good bearing capacity data of a single test point raising the basic bearing capacity of the entire wind turbine foundation, different bearing capacity weights are set for different test points. The expression is:
[0083] ; In the formula, represents the bearing capacity weight of the tth test point; Indicates the number of test points on the current collapsible wind turbine foundation; and They represent the compaction degree and soil density distinction value of the kth test point respectively; and They respectively represent the compaction degree and soil density distinction value of the tth test point.
[0084] It should be noted that: if the soil density and cohesion of a single test point are relatively high after compaction piles are used around the test point, the bearing capacity of the test point is relatively large, and the compaction degree and soil density difference value of the test point are relatively large, so the bearing capacity weight of the test point is relatively small. The main purpose is to reduce the contribution of the bearing capacity of the test point to the final bearing capacity of the entire foundation, and to avoid raising the overall foundation bearing capacity due to the excessive bearing capacity of a single test point. At the same time, the sum of the bearing capacity weights of all test points is 1. The schematic diagram of the bearing capacity weight determination process is shown in the figure below. Figure 4 shown.
[0085] Step 5, obtaining the ultimate bearing capacity of each test point, and combining the pressure characteristic value and the bearing capacity weight to determine the comprehensive foundation bearing capacity of the wind turbine foundation, and correcting the comprehensive foundation bearing capacity to obtain the foundation bearing capacity of the wind turbine foundation.
[0086] The ultimate bearing capacity of each test point is obtained using the Code for Design of Building Foundations (GB50007-2011). The ultimate bearing capacity is obtained as follows:
[0087] When one of the following situations occurs, the corresponding previous load level is the ultimate bearing capacity. The following situations include: (1) the soil around the bearing plate is obviously squeezed laterally; (2) the settlement increases sharply, and a steep drop section appears in the load-settlement curve; (3) under a certain load level, the settlement rate cannot reach the stability standard within 24 hours.
[0088] The product of the ultimate bearing capacity of each test point and one-half is calculated and recorded as the one-half value. The minimum value between the one-half value and the pressure characteristic value of each test point is taken as the bearing capacity characteristic value of each test point.
[0089] The product of the bearing capacity characteristic value and the bearing capacity weight of each test point is calculated and recorded as the weighted product, and the accumulated value of the weighted product of all test points is taken as the comprehensive foundation bearing capacity of the wind turbine foundation.
[0090] Since this embodiment adopts a shallow plate load test, it is necessary to correct the comprehensive foundation bearing capacity of the wind turbine foundation according to Article 5.2.4 of the Code for Design of Building Foundations (GB50007-2011) to obtain the current foundation bearing capacity of the wind turbine foundation.
[0091] In summary, this application determines the compaction degree of each test point by analyzing the change of the settlement data points in the linear stage of each test point, the size of the change trend, and the distribution of the settlement data points in the nonlinear stage, reflecting the compaction of the foundation at each test point; combined with the difference in the pressure characteristic value between each test point and the remaining test points in the neighborhood, and the number of compaction piles in the neighborhood of each test point, the soil density distinction value of each test point is determined to reflect the difference in the compaction of the foundation between each test point and the remaining test points in the neighborhood;
[0092] Furthermore, based on the compaction degree and soil density distinction value of all test points, the bearing capacity weight of each test point is determined, the bearing capacity characteristic values of all test points are weightedly fused, and the fusion result is corrected to obtain the basic bearing capacity of the wind turbine foundation. Compared with the traditional method of obtaining the basic bearing capacity of the foundation by the averaging method, the present application takes into account the differences in soil properties between different test points and the differences in the distribution of compaction piles around different test points. Using a specific bearing capacity weight for each test point can better integrate the bearing capacity of each test point on the wind turbine foundation, avoid the situation where the overall bearing capacity of the foundation is increased due to the better bearing effect of a single test point, and improve the accuracy of calculating the bearing capacity of the foundation of a wind turbine on a collapsible foundation.
[0093] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.
[0094] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the basic features of the present application. Therefore, no matter from which point of view, the above embodiments of the present application should be regarded as exemplary and non-restrictive.
Claims
1. A method for calculating the bearing capacity of a wind turbine foundation on collapsible soil, characterized in that: The method comprises the following steps: Obtain the settlement of each test point on the wind turbine foundation at each pressure value; Each pressure value and the corresponding settlement amount are combined into a two-dimensional settlement data point, and the inflection point in the settlement data point of each test point is obtained. The settlement data point of each test point is divided into two parts: a linear stage and a nonlinear stage, and the pressure value of the inflection point is used as the pressure characteristic value of each test point; Comprehensively analyze the linear changes of settlement data points in the linear stage of each test point, as well as the distribution of settlement data points in the nonlinear stage, to determine the data stability of each test point; Based on the change trend of all settlement data points in the linear stage of each test point and the change trend of two adjacent settlement data points, the data tilt degree of each test point is determined; The compaction degree of each test point is obtained by combining the data stability and data inclination of each test point; Determine the soil compaction distinction value of any test point based on the number of compaction piles within the neighborhood of any test point and the difference in pressure characteristic values between any test point and all test points within its neighborhood; Based on the compaction degree and soil density differentiation value of all test points, the bearing capacity weight of each test point is determined; Obtaining the ultimate bearing capacity of each test point, and determining the comprehensive foundation bearing capacity of the wind turbine foundation by combining the pressure characteristic value and the bearing capacity weight, and correcting the comprehensive foundation bearing capacity to obtain the foundation bearing capacity of the wind turbine foundation; The calculation method of the data stability is: ; In the formula, Indicates the data stability of the t-th test point; Indicates the goodness of fit of the settlement data points in the nonlinear stage of the t-th test point; represents the number of settlement data points in the linear stage of the t-th test point; represents the pressure value of the ith settlement data point in the linear stage of the tth test point; obtains the fitting straight line of all settlement data points in the linear stage of the tth test point, represents the pressure value corresponding to the settlement amount of the ith settlement data point in the linear stage of the tth test point on the fitting straight line; The expression of the data skew degree is: ; In the formula, Indicates the degree of data skewness at the t-th test point; represents the slope of the fitted straight line at the t-th test point; It represents the mean value of the slope of the straight line determined by all two adjacent settlement data points in the linear stage of the t-th test point; The compaction degree is the ratio of the data stability degree to the data inclination degree of each test point; The process of determining the soil density distinction value is as follows: Calculate the difference in pressure characteristic values between any test point and each test point in its neighborhood except itself, and record it as pressure characteristic difference; Calculate the mean of all the pressure characteristic differences at any test point, and record it as the difference mean; The fusion result of the number of compaction piles and the difference mean is used as the soil density distinction value of any test point; The process of determining the bearing capacity weight is as follows: Calculate the sum of the compaction degree and soil density difference value of each test point; Calculate the cumulative sum of the reciprocals of the sum values of all test points; Based on the cumulative sum and the sum value of each test point, the bearing capacity weight of each test point is obtained.
2. A method for calculating the bearing capacity of a wind turbine foundation on collapsible soil as claimed in claim 1, characterized in that: The soil compaction distinction value is the product of the number of the compaction piles and the mean value of the differences.
3. The method for calculating the bearing capacity of a wind turbine foundation on collapsible soil according to claim 1, characterized in that: The bearing capacity weight is the ratio of the cumulative sum to the sum of each test point.
4. The method for calculating the bearing capacity of a wind turbine foundation on collapsible soil according to claim 1, characterized in that: The determination process of the comprehensive foundation bearing capacity is as follows: Based on the magnitude relationship between the ultimate bearing capacity and the pressure characteristic value of each test point, the bearing capacity characteristic value of each test point is determined; The product of the bearing capacity characteristic value and the bearing capacity weight of each test point is calculated and recorded as the weighted product, and the accumulated value of the weighted product of all test points is taken as the comprehensive foundation bearing capacity of the wind turbine foundation.
5. A method for calculating the bearing capacity of a wind turbine foundation on collapsible ground as claimed in claim 4, characterized in that: The bearing capacity characteristic value is the minimum value between the pressure characteristic value of each test point and half of the ultimate bearing capacity.