Prestressed concrete pile bearing performance analysis method based on finite element

Abstract

The invention relates to the technical field of data processing, in particular to a prestressed concrete pile bearing performance analysis method based on finite elements. The method comprises the steps that on the basis of the sinking sequence of a plurality of piles in a pile group, iterative correction is conducted on first compactness information of a pile sinking area before pile sinking, so that second compactness information after pile sinking is obtained; performing pile sinking performance prediction according to the second compactness information to obtain predicted performance information indicating the bearing performance of the pile group; the ith iteration in the iteration correction comprises the steps of determining the radial environment stress and the radial pile sinking stress corresponding to the target position in the ith iteration based on the soil layer compactness corresponding to the target position in the (i-1) th iteration, and optimizing the soil layer compactness corresponding to the target position in the (i-1) th iteration according to the radial environment stress and the radial pile sinking stress, and obtaining the soil layer compactness corresponding to the target position in the ith iteration. According to the method, the soil layer compactness change in the pile sinking process can be dynamically adapted, and the accuracy of the predicted pile foundation bearing performance is improved.

Description

Technical Field

[0001] This invention relates to the field of data processing technology, and specifically to a method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method. Background Technology

[0002] As the main load-bearing component in building foundation treatment and pile foundation engineering, the stress performance of prestressed concrete pipe piles is directly related to the safety and stability of the superstructure.

[0003] When setting up pile foundations based on the static pressure method in sandy areas, it was found that the existing pile foundation bearing capacity assessment relies heavily on static load tests and empirical formulas, which are difficult to adapt to the changes in soil layers during the pile driving process. This makes the subsequent prediction of pile foundation bearing capacity inaccurate. Summary of the Invention

[0004] The purpose of this invention is to provide a finite element method for analyzing the bearing capacity of prestressed concrete piles, which solves the technical problem of insufficient accuracy in predicting the bearing capacity of pile foundations in existing technologies.

[0005] In a first aspect, one embodiment of the present invention provides a method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method, the method comprising: Based on the sinking sequence of multiple piles within the pile group, the first density information of the pile driving area is iteratively corrected to obtain the second density information. The piles are prestressed concrete pipe piles. The first density information is used to indicate the soil density at each location within the pile driving area before the pile group intervention, and the second density information is used to predict the soil density at each location within the pile driving area after the pile group is driven. Based on the second density information, the pile driving performance is predicted to obtain the predicted performance information indicating the bearing capacity of the pile group. The i-th iteration in the iterative correction includes: Based on the soil density corresponding to the target location in the (i-1)th iteration, the radial environmental stress and radial pile driving stress corresponding to the target location in the i-th iteration are determined. The target location is a location within the pile driving area. The radial environmental stress is the radial stress naturally generated at the corresponding location in the corresponding iteration due to the insertion of the corresponding pile into the soil. The radial pile driving stress is the radial stress formed at the corresponding location in the corresponding iteration due to the energy transmission of the pile driving of the corresponding pile. i is a positive integer, and when i=1, the soil density corresponding to the target location in the (i-1)th iteration comes from the first density information. Based on the radial environmental stress and radial pile driving stress corresponding to the target position in the i-th iteration, the soil density corresponding to the target position in the (i-1)-th iteration is optimized to obtain the soil density corresponding to the target position in the i-th iteration.

[0006] In some embodiments, the step of obtaining the radial environmental stress corresponding to the target position in the i-th iteration includes: Based on the column radius of the pile corresponding to the i-th iteration, the interval between the target position and the settlement position corresponding to the i-th iteration, and the median particle size of the sand at the target position, the compaction influence factor corresponding to the target position in the i-th iteration is determined, where the compaction influence factor indicates the degree to which the corresponding position is affected by the corresponding pile. Based on the radial environmental stress corresponding to the target position in the (i-1)th iteration, the force efficiency value corresponding to the target position in the i-th iteration, and the compaction influence factor corresponding to the target position in the i-th iteration, the radial environmental stress corresponding to the target position in the i-th iteration is determined. The force efficiency value indicates the radial environmental stress transmission efficiency at the corresponding position in the corresponding iteration. When i=1, the radial environmental stress corresponding to the target position in the (i-1)th iteration is determined based on the first compaction information.

[0007] In some embodiments, the step of determining the compaction influence factor corresponding to the target location in the i-th iteration based on the column radius of the pile corresponding to the i-th iteration, the interval distance between the target location and the settlement location corresponding to the i-th iteration, and the median particle size of the sand at the target location includes: Analyze the difference between the column radius of the pile corresponding to the i-th iteration and the median particle size of the sand at the target location to obtain the pile-particle difference value corresponding to the target location in the i-th iteration; Based on the pile-particle difference value corresponding to the target position in the i-th iteration and the interval distance between the target position and the sinking position corresponding to the i-th iteration, the compaction influence factor corresponding to the target position in the i-th iteration is determined. The compaction influence factor is positively correlated with the corresponding pile-particle difference value and negatively correlated with the corresponding interval distance.

[0008] In some embodiments, the force efficiency value is determined based on the internal friction angle at the corresponding position under the corresponding iteration, and the internal friction angle at the target position under the i-th iteration is determined based on the soil density corresponding to the target position in the (i-1)-th iteration.

[0009] In some embodiments, the step of determining the radial environmental stress corresponding to the target position in the i-th iteration based on the radial environmental stress corresponding to the target position in the (i-1)-th iteration, the force efficiency value corresponding to the target position in the i-th iteration, and the compaction influence factor corresponding to the target position in the i-th iteration includes: Based on the force efficiency value corresponding to the target position in the i-th iteration, the compaction influence factor corresponding to the target position in the i-th iteration is nonlinearly modulated to obtain the stress correction coefficient corresponding to the target position in the i-th iteration. Here, the compaction influence factor corresponding to the target position in the i-th iteration is greater than 1, and the force efficiency value corresponding to the target position in the i-th iteration is also greater than 1. Calculate the product of the stress correction coefficient corresponding to the target position in the i-th iteration and the radial environmental stress corresponding to the target position in the (i-1)-th iteration to obtain the radial environmental stress corresponding to the target position in the i-th iteration.

[0010] In some embodiments, the step of obtaining the radial pile driving stress corresponding to the target position in the i-th iteration includes: Based on the interval between the target location and the sinking location corresponding to the i-th iteration, the column radius of the pile corresponding to the i-th iteration, the shear parameters of the target location in the i-th iteration, and the soil density corresponding to the target location in the (i-1)-th iteration, the energy conversion rate of the target location in the i-th iteration is determined. The energy conversion rate indicates the efficiency of the pile driving energy in the corresponding iteration in converting into radial stress at the corresponding location, and the shear parameters indicate the maximum shear strength of the unit effective normal stress at the corresponding location in the corresponding iteration. Based on the energy conversion rate at the target location in the i-th iteration and the pile driving energy corresponding to the i-th iteration, the radial pile driving stress corresponding to the target location in the i-th iteration is determined.

[0011] In some embodiments, the shear resistance parameter of the target location in the i-th iteration is determined based on the tangent of the internal friction angle of the target location in the i-th iteration, and the internal friction angle of the target location in the i-th iteration is determined based on the soil density corresponding to the target location in the (i-1)-th iteration.

[0012] In some embodiments, the energy conversion rate is negatively correlated with the corresponding interval distance, positively correlated with the corresponding column radius, positively correlated with the corresponding shear resistance parameter, and positively correlated with the corresponding soil density.

[0013] In some embodiments, the step of optimizing the soil density corresponding to the target location in the (i-1)th iteration based on the radial environmental stress and radial pile driving stress corresponding to the target location in the i-th iteration to obtain the soil density corresponding to the target location in the i-th iteration includes: Based on the radial environmental stress and radial pile driving stress corresponding to the target position in the i-th iteration, determine the radial comprehensive stress corresponding to the target position in the i-th iteration; Analyze the difference between the radial composite stress and the radial reference stress corresponding to the target position in the i-th iteration to determine the radial stress intensity corresponding to the target position in the i-th iteration; Based on the radial stress intensity corresponding to the target position in the i-th iteration, the soil density corresponding to the target position in the (i-1)-th iteration is optimized to obtain the soil density corresponding to the target position in the i-th iteration.

[0014] In some embodiments, the step of optimizing the soil density corresponding to the target location in the (i-1)th iteration based on the radial stress intensity corresponding to the target location in the i-th iteration to obtain the soil density corresponding to the target location in the i-th iteration includes: The radial stress intensity and redundant porosity at the target location in the i-th iteration are used to determine the porosity change index at the target location in the i-th iteration. The redundant porosity at the target location in the i-th iteration indicates the difficulty of closing the soil pores at the target location in the i-th iteration. The void ratio change index corresponding to the target location in the i-th iteration is used to amplify the soil density corresponding to the target location in the (i-1)-th iteration, so as to obtain the soil density corresponding to the target location in the i-th iteration.

[0015] Secondly, another embodiment of the present invention provides a finite element-based prestressed concrete pile bearing capacity analysis system, the system comprising: The compaction iteration module is used to iteratively correct the first compaction information of the pile driving area based on the sinking order of multiple piles in the pile group to obtain the second compaction information. The piles are prestressed concrete pipe piles. The first compaction information is used to indicate the soil compaction at each location in the pile driving area before the pile group intervention. The second compaction information is used to predict the soil compaction at each location in the pile driving area after the pile group is driven. The performance prediction module is used to predict the pile driving performance based on the second compaction information, so as to obtain predicted performance information indicating the bearing capacity of the pile group. The i-th iteration in the iterative correction includes: Based on the soil density corresponding to the target location in the (i-1)th iteration, the radial environmental stress and radial pile driving stress corresponding to the target location in the i-th iteration are determined. The target location is a location within the pile driving area. The radial environmental stress is the radial stress naturally generated at the corresponding location in the corresponding iteration due to the insertion of the corresponding pile into the soil. The radial pile driving stress is the radial stress formed at the corresponding location in the corresponding iteration due to the energy transmission of the pile driving of the corresponding pile. i is a positive integer, and when i=1, the soil density corresponding to the target location in the (i-1)th iteration comes from the first density information. Based on the radial environmental stress and radial pile driving stress corresponding to the target position in the i-th iteration, the soil density corresponding to the target position in the (i-1)-th iteration is optimized to obtain the soil density corresponding to the target position in the i-th iteration.

[0016] Thirdly, in another embodiment of the present invention, an electronic device is provided, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the method described in the first aspect.

[0017] Fourthly, in another embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the method described in the first aspect.

[0018] The present invention has the following beneficial effects: This invention uses the soil density at each location within the pile driving area before the pile group intervention as the starting point for iteration. Based on the sinking sequence of multiple piles within the pile group, it iteratively analyzes the cumulative change in soil density at each location within the pile driving area after being subjected to the action of multiple piles. During each iteration, it integrates the radial stress naturally generated by the intervention of the corresponding pile in the soil layer and the radial stress formed by the energy transmission of the corresponding pile during pile driving to accurately simulate the real radial stress experienced by each location within the pile driving area during each iteration. This completes the accurate correction of the soil density at each location within the pile driving area. After the iteration is completed, based on the second density information that can accurately reflect the real soil density at each location within the pile driving area after the pile group is driven, the pile driving performance is predicted, thereby obtaining predictive performance information that can more accurately indicate the bearing capacity of the pile group. Attached Figure Description

[0019] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart of a finite element-based method for analyzing the bearing capacity of prestressed concrete piles, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of a prestressed concrete pile bearing capacity analysis system based on finite element method provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0021] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a finite element-based method for analyzing the bearing capacity of prestressed concrete piles according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable manner.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] The following description, in conjunction with the accompanying drawings, details a specific scheme for the finite element-based method for analyzing the bearing capacity of prestressed concrete piles provided by this invention.

[0024] In one embodiment, the present invention provides a method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method, such as... Figure 1 As shown, the method includes: Step S1: Based on the sinking sequence of multiple piles in the pile group, the first density information of the pile sinking area is iteratively corrected to obtain the second density information.

[0025] The pile is a prestressed concrete pipe pile. The first density information is used to indicate the soil density at each location in the pile driving area before the pile group is involved. The second density information is used to predict the soil density at each location in the pile driving area after the pile group is driven.

[0026] The i-th iteration in the iterative correction includes: Based on the soil density corresponding to the target location in the (i-1)th iteration, the radial environmental stress and radial pile driving stress corresponding to the target location in the i-th iteration are determined. The target location is a location within the pile driving area. The radial environmental stress is the radial stress naturally generated at the corresponding location in the corresponding iteration due to the insertion of the corresponding pile into the soil. The radial pile driving stress is the radial stress formed at the corresponding location in the corresponding iteration due to the energy transmission of the pile driving of the corresponding pile. i is a positive integer, and when i=1, the soil density corresponding to the target location in the (i-1)th iteration comes from the first density information. Based on the radial environmental stress and radial pile driving stress corresponding to the target position in the i-th iteration, the soil density corresponding to the target position in the (i-1)-th iteration is optimized to obtain the soil density corresponding to the target position in the i-th iteration.

[0027] The aforementioned pile driving area should be understood as a sandy area where prestressed concrete pipe piles are to be used for pile foundation installation. The aforementioned pile group should be understood as a collection of multiple prestressed concrete pipe piles to be placed in the pile driving area. The number of multiple prestressed concrete pipe piles in the pile driving area is determined based on the adaptability of the construction requirements of the building to be built in the pile driving area. Generally speaking, the higher the seismic requirements indicated by the construction requirements of the building to be built, the more multiple prestressed concrete pipe piles there are in the pile driving area. Also, the higher the total height indicated by the construction requirements of the building to be built, the more multiple prestressed concrete pipe piles there are in the pile driving area.

[0028] Multiple piles within the pile group will be sequentially arrayed in the pile driving area using the static pressure method. Each pile is marked with a corresponding sinking sequence. In this invention, the closer to the center of the pile driving area, the smaller the sinking sequence of the corresponding pile, and the earlier the corresponding pile is placed at the corresponding pile driving position.

[0029] In this invention, multiple sampling locations are determined within the pile driving area according to a set sampling rule (e.g., the distance between adjacent sampling points is set to 0.5 meters). The measured void ratio of each sampling location within the pile driving area before the pile group intervention is measured (by measuring the natural density, water content, and soil particle specific gravity of the soil layer at the corresponding sampling location in the laboratory and processing it using the three-phase index conversion formula). Combined with the maximum and minimum void ratio achievable by sand, the soil density (also known as relative density) of each sampling location within the pile driving area before the pile group intervention is determined accordingly. The soil density of multiple sampling locations within the pile driving area before the pile group intervention is aggregated to form the aforementioned first density information.

[0030] For example, the soil compaction at a sampling location within the pile driving area before the pile group intervention. It can be represented as: in, This indicates the maximum void ratio that sand can achieve. This indicates the minimum void ratio that sand can achieve. This indicates the measured void ratio at the corresponding sampling location before pile driving, prior to the intervention of the pile group.

[0031] It should be noted that, in this invention, the bearing capacity prediction of the pile group within the pile driving area is specifically carried out through data simulation. The preliminary preparations for the data simulation include: Based on the first density information and the geological data corresponding to the pile driving area (such as natural density, water content, particle size distribution curve, internal friction angle, elastic model, compression index, etc.), a soil model indicating the pile driving area is constructed; based on the column radius (the end face of the pile column is circular in this invention) and column length of each pile column in the pile group, a pile model indicating the pile column is constructed.

[0032] Specifically, a coupled Eulerian-Lagrange analysis method is adopted. The pile model uses Lagrange elements to ensure accurate tracking of its structural deformation, while the soil model uses Eulerian elements to enable it to undergo large flow and compression deformations, avoiding distortion of traditional meshes under large deformation conditions.

[0033] The pile-soil interface adopts a "surface-to-surface" contact form. The normal contact is set as rigid contact to avoid the pile and soil penetrating each other. The tangential contact adopts a friction model based on the Coulomb friction relationship, and its friction coefficient is determined according to the test results of soil-concrete interface in triaxial shear test.

[0034] In some embodiments, the step of obtaining the radial environmental stress corresponding to the target position in the i-th iteration includes: Based on the column radius of the pile corresponding to the i-th iteration, the interval between the target position and the settlement position corresponding to the i-th iteration, and the median particle size of the sand at the target position, the compaction influence factor corresponding to the target position in the i-th iteration is determined, where the compaction influence factor indicates the degree to which the corresponding position is affected by the corresponding pile. Based on the radial environmental stress corresponding to the target position in the (i-1)th iteration, the force efficiency value corresponding to the target position in the i-th iteration, and the compaction influence factor corresponding to the target position in the i-th iteration, the radial environmental stress corresponding to the target position in the i-th iteration is determined. The force efficiency value indicates the radial environmental stress transmission efficiency at the corresponding position in the corresponding iteration. When i=1, the radial environmental stress corresponding to the target position in the (i-1)th iteration is determined based on the first compaction information.

[0035] The force efficiency value is determined based on the internal friction angle at the corresponding position in the corresponding iteration. The internal friction angle at the target position in the i-th iteration is determined based on the soil density at the target position in the (i-1)-th iteration. It should be understood that the internal friction angle at the target position in the i-th iteration is positively correlated with the soil density at the target position in the (i-1)-th iteration.

[0036] It should be noted that as the pile continues to fall, the radial environmental stress at each sampling location within the pile driving area also increases continuously. Therefore, in this invention, the radial environmental stress corresponding to the target location in the (i-1)th iteration is less than the radial environmental stress corresponding to the target location in the i-th iteration.

[0037] In this invention, the radial stress naturally generated at the corresponding position due to the insertion of the corresponding pile into the soil layer during the corresponding iteration should be understood as: the radial stress generated at the corresponding position due to the displacement of soil at the corresponding sinking position caused by the insertion of the corresponding pile into the soil layer during the corresponding iteration, without considering the influence of the pile driving energy during the insertion. Analysis revealed that the larger the radius of the corresponding pile, the greater the mass of soil displaced during its insertion into the soil layer, and the greater the radial environmental stress experienced at the corresponding position; furthermore, the smaller the distance between the target position and the sinking position corresponding to the i-th iteration, the stronger the influence of the soil displaced by the corresponding pile at the corresponding position, and the greater the radial environmental stress experienced at the corresponding position; additionally, the smaller the median particle size of the sand at the corresponding position, the more pronounced the fluid-like tendency of the sand at the corresponding position, the better the transmission effect of radial stress, and the greater the radial environmental stress experienced at the corresponding position.

[0038] Specifically, the steps for determining the compaction influence factor corresponding to the target location in the i-th iteration, based on the pile radius corresponding to the i-th iteration, the interval between the target location and the settlement location corresponding to the i-th iteration, and the median particle size of the sand at the target location, include: Analyze the difference between the column radius of the pile corresponding to the i-th iteration and the median particle size of the sand at the target location to obtain the pile-particle difference value corresponding to the target location in the i-th iteration; Based on the pile-particle difference value corresponding to the target position in the i-th iteration and the interval distance between the target position and the sinking position corresponding to the i-th iteration, the compaction influence factor corresponding to the target position in the i-th iteration is determined. The compaction influence factor is positively correlated with the corresponding pile-particle difference value and negatively correlated with the corresponding interval distance (the numerical correspondence between the two can be obtained by looking up a table).

[0039] And, the step of determining the radial environmental stress corresponding to the target position in the i-th iteration based on the radial environmental stress corresponding to the target position in the (i-1)-th iteration, the force efficiency value corresponding to the target position in the i-th iteration, and the compaction influence factor corresponding to the target position in the i-th iteration, includes: Based on the force efficiency value corresponding to the target position in the i-th iteration, the compaction influence factor corresponding to the target position in the i-th iteration is nonlinearly modulated (e.g., using an exponential function to adapt to the case where the radial stress attenuation is more severe at the sampling position with a larger internal friction angle) to obtain the stress correction coefficient corresponding to the target position in the i-th iteration. Here, the compaction influence factor corresponding to the target position in the i-th iteration is greater than 1, and the force efficiency value corresponding to the target position in the i-th iteration is also greater than 1. Calculate the product of the stress correction coefficient corresponding to the target position in the i-th iteration and the radial environmental stress corresponding to the target position in the (i-1)-th iteration to obtain the radial environmental stress corresponding to the target position in the i-th iteration.

[0040] For example, the pile-particle difference value corresponding to the target position in the i-th iteration. (The nonlinear effect of the relative size between the indicator pile and soil particles on the soil displacement effect) can be expressed as: in, Let represent the column radius corresponding to the i-th iteration. This indicates the median grain size of the sand at the target location. This represents the hyperbolic tangent function (used to standardize the ratio of column radius to median particle size).

[0041] The radial environmental stress corresponding to the target position in the i-th iteration It can be represented as: in, This represents the radial environmental stress corresponding to the target position in the (i-1)th iteration. This represents the distance between the target location and the sinking location corresponding to the i-th iteration. This represents the normalization function (specifically, the ratio of the spacing distance to a set distance threshold, where the distance threshold indicates the maximum distance between the sampling position and the sinking position in the pile driving area). This represents the force efficiency value corresponding to the target position in the i-th iteration. Indicates the compaction influence factor corresponding to the target position in the i-th iteration.

[0042] The force efficiency value corresponding to the target position in the i-th iteration It can be represented as: Where sin represents the sine function, Let represent the internal friction angle of the target position in the i-th iteration.

[0043] In some embodiments, the step of obtaining the radial pile driving stress corresponding to the target position in the i-th iteration includes: Based on the interval between the target location and the sinking location corresponding to the i-th iteration, the column radius of the pile corresponding to the i-th iteration, the shear parameters of the target location in the i-th iteration, and the soil density corresponding to the target location in the (i-1)-th iteration, the energy conversion rate of the target location in the i-th iteration is determined. The energy conversion rate indicates the efficiency of the pile driving energy in the corresponding iteration in converting into radial stress at the corresponding location, and the shear parameters indicate the maximum shear strength of the unit effective normal stress at the corresponding location in the corresponding iteration. Based on the energy conversion rate at the target location in the i-th iteration and the pile driving energy corresponding to the i-th iteration, the radial pile driving stress corresponding to the target location in the i-th iteration is determined.

[0044] Specifically, the shear resistance parameter of the target location in the i-th iteration is determined based on the tangent of the internal friction angle of the target location in the i-th iteration, and the internal friction angle of the target location in the i-th iteration is determined based on the soil density corresponding to the target location in the (i-1)-th iteration.

[0045] Among them, the energy conversion rate is negatively correlated with the corresponding interval distance, positively correlated with the corresponding column radius, positively correlated with the corresponding shear resistance parameter, and positively correlated with the corresponding soil density.

[0046] The aforementioned pile driving energy can be obtained based on pressure sensors. The specific process is as follows: the actual pile driving energy of piles of different sizes is collected based on pressure sensors, and a mapping function between the pile size and the actual pile driving energy is constructed accordingly. Then, the mapping function is used to process the pile size data under the corresponding iteration to obtain the pile driving energy under the corresponding iteration.

[0047] It should be understood that the closer the distance between the target position and the sinking position corresponding to the i-th iteration, the higher the energy intensity of the pile driving energy in the corresponding iteration is transmitted to the target position, and the higher the efficiency of the pile driving energy in the corresponding iteration in converting into radial stress at the target position (that is, the higher the energy conversion rate).

[0048] The larger the column radius of the pile corresponding to the i-th iteration, the wider the contact surface between the pile and the pile driving area under the corresponding iteration, the larger the soil displacement volume, and the higher the efficiency of the pile driving energy in the target position to be converted into radial stress under the corresponding iteration.

[0049] The higher the maximum shear strength of the unit effective normal stress at the corresponding position under the corresponding iteration, the stronger the energy absorption capacity of the corresponding position under the corresponding iteration, and the higher the efficiency of the pile driving energy in converting into radial stress at the target position under the corresponding iteration.

[0050] The higher the soil density at the target location in the (i-1)th iteration, the higher the soil density at the corresponding location in the corresponding iteration, and the higher the efficiency of converting pile driving energy into radial stress at the target location in the corresponding iteration.

[0051] For example, the energy conversion rate at the target location in the i-th iteration It can be represented as: in, This represents the ideal energy conversion rate (indicating the maximum ratio of energy from pile driving to corresponding radial stress under ideal conditions, with a value between 0 and 1). This represents the geometric variation coefficient (used to regulate the rate at which pile driving energy changes with distance and pile size; the value is greater than 0). Indicates the tangent function, Let represent the shear resistance parameter at the target location in the i-th iteration. This represents the soil density corresponding to the target location in the (i-1)th iteration. This represents the nonlinear coefficient (used to adjust the degree of influence of soil compaction on energy conversion rate, with a value greater than or equal to 1).

[0052] The radial pile driving stress corresponding to the target position in the i-th iteration It can be represented as: in, This represents the pile driving energy corresponding to the i-th iteration.

[0053] In this invention, the radial environmental stress and radial pile stress corresponding to the target location can be obtained by referring to the process of obtaining the radial environmental stress and radial pile stress at each sampling location in the pile driving area under the corresponding iteration. To avoid repetition, it will not be described in detail here.

[0054] Further, the step of optimizing the soil density at the target location in the (i-1)th iteration based on the radial environmental stress and radial pile driving stress corresponding to the target location in the i-th iteration, to obtain the soil density at the target location in the i-th iteration, includes: Based on the radial environmental stress and radial pile driving stress corresponding to the target position in the i-th iteration, determine the radial comprehensive stress corresponding to the target position in the i-th iteration; Analyze the difference between the radial composite stress and the radial reference stress corresponding to the target position in the i-th iteration to determine the radial stress intensity corresponding to the target position in the i-th iteration; Based on the radial stress intensity corresponding to the target position in the i-th iteration, the soil density corresponding to the target position in the (i-1)-th iteration is optimized to obtain the soil density corresponding to the target position in the i-th iteration.

[0055] The aforementioned radial reference stress should be understood as the maximum radial stress that sand can withstand. This value can be set based on experience or determined experimentally. This invention does not limit the method of obtaining it.

[0056] In one example, the ratio between the radial combined stress and the radial reference stress at the target position in the i-th iteration can be determined as the radial stress intensity at the target position in the i-th iteration.

[0057] Furthermore, the step of optimizing the soil density corresponding to the target position in the (i-1)th iteration based on the radial stress intensity corresponding to the target position in the i-th iteration to obtain the soil density corresponding to the target position in the i-th iteration includes: The radial stress intensity and redundant porosity at the target location in the i-th iteration are used to determine the porosity change index at the target location in the i-th iteration. The redundant porosity at the target location in the i-th iteration indicates the difficulty of closing the soil pores at the target location in the i-th iteration. The void ratio change index corresponding to the target location in the i-th iteration is used to amplify the soil density corresponding to the target location in the (i-1)-th iteration, so as to obtain the soil density corresponding to the target location in the i-th iteration.

[0058] For example, the soil density corresponding to the target location in the i-th iteration It can be represented as: in, This represents the radial stress intensity corresponding to the target position in the i-th iteration. Let represent the redundancy porosity corresponding to the target position in the i-th iteration. This represents the porosity corresponding to the target position in the (i-1)th iteration.

[0059] Wherein, the porosity corresponding to the target position in the (i-1)th iteration It can be represented as: .

[0060] Step S2: Based on the second compaction information, predict the pile driving performance to obtain the predicted performance information indicating the bearing capacity of the pile group.

[0061] The predicted performance information mentioned above includes at least the pile side resistance and pile end resistance corresponding to the pile group. In application, the second density information can be processed based on a neural network model to obtain the predicted performance information, or empirical formulas can be used to process the second density information to obtain the predicted performance information.

[0062] In summary, this invention uses the soil density at each location within the pile driving area before the pile group intervention as the starting point for iteration. Based on the sinking sequence of multiple piles within the pile group, it iteratively analyzes the cumulative change in soil density at each location within the pile driving area after being subjected to the action of multiple piles. During each iteration, it integrates the radial stress naturally generated by the intervention of the corresponding pile in the soil layer and the radial stress formed by the energy transmission of the corresponding pile during pile driving to accurately simulate the real radial stress experienced by each location within the pile driving area during each iteration. This completes the accurate correction of the soil density at each location within the pile driving area. After the iteration is completed, based on the second density information that accurately reflects the real soil density at each location within the pile driving area after the pile group is driven, pile driving performance is predicted, thereby obtaining predictive performance information that can more accurately indicate the bearing capacity of the pile group.

[0063] In one embodiment, the present invention also provides a finite element method-based prestressed concrete pile bearing capacity analysis system 200, such as... Figure 2 As shown, the system 200 includes: The compaction iteration module 201 is used to iteratively correct the first compaction information of the pile driving area based on the sinking order of multiple piles in the pile group to obtain the second compaction information. The piles are prestressed concrete pipe piles. The first compaction information is used to indicate the soil compaction at each location in the pile driving area before the pile group intervention. The second compaction information is used to predict the soil compaction at each location in the pile driving area after the pile group is driven. The performance prediction module 202 is used to predict the pile driving performance based on the second compaction information to obtain predicted performance information indicating the bearing capacity of the pile group. The i-th iteration in the iterative correction includes: Based on the soil density corresponding to the target location in the (i-1)th iteration, the radial environmental stress and radial pile driving stress corresponding to the target location in the i-th iteration are determined. The target location is a location within the pile driving area. The radial environmental stress is the radial stress naturally generated at the corresponding location in the corresponding iteration due to the insertion of the corresponding pile into the soil. The radial pile driving stress is the radial stress formed at the corresponding location in the corresponding iteration due to the energy transmission of the pile driving of the corresponding pile. i is a positive integer, and when i=1, the soil density corresponding to the target location in the (i-1)th iteration comes from the first density information. Based on the radial environmental stress and radial pile driving stress corresponding to the target position in the i-th iteration, the soil density corresponding to the target position in the (i-1)-th iteration is optimized to obtain the soil density corresponding to the target position in the i-th iteration.

[0064] It should be noted that the system provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the computer equipment can be divided into different functional modules to complete all or part of the functions described above. In addition, the finite element-based prestressed concrete pile bearing capacity analysis system and the finite element-based prestressed concrete pile bearing capacity analysis method embodiment provided in the above embodiments belong to the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0065] This invention also provides an electronic device. Please refer to [link to relevant documentation]. Figure 3 The electronic device may include a processor 301, a memory 302, and a program 3021 stored in the memory 302 and capable of running on the processor 301.

[0066] When program 3021 is executed by processor 301, it can achieve the following: Figure 1 Any steps in the corresponding method embodiments and the achievement of the same beneficial effects will not be repeated here.

[0067] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by hardware related to program instructions, and the program can be stored in a readable medium.

[0068] This invention also provides a readable storage medium storing a computer program, which, when executed by a processor, can perform the above-described functions. Figure 1 Any step in the corresponding method embodiment can achieve the same technical effect, and will not be repeated here to avoid repetition.

[0069] The computer-readable storage medium of this invention can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. For example, a computer-readable storage medium can be an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0070] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0071] The program code contained on the storage medium can be transmitted using any suitable medium, including but not limited to wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0072] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or terminal. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0073] This invention also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned steps to implement the finite element-based method for analyzing the bearing capacity of prestressed concrete piles provided in the above embodiments.

[0074] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0075] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method, characterized in that, The method includes: Based on the sinking sequence of multiple piles within the pile group, the first density information of the pile driving area is iteratively corrected to obtain the second density information. The piles are prestressed concrete pipe piles. The first density information is used to indicate the soil density at each location within the pile driving area before the pile group intervention, and the second density information is used to predict the soil density at each location within the pile driving area after the pile group is driven. Based on the second density information, the pile driving performance is predicted to obtain the predicted performance information indicating the bearing capacity of the pile group. The i-th iteration in the iterative correction includes: Based on the soil density corresponding to the target location in the (i-1)th iteration, the radial environmental stress and radial pile driving stress corresponding to the target location in the i-th iteration are determined. The target location is a location within the pile driving area. The radial environmental stress is the radial stress naturally generated at the corresponding location in the corresponding iteration due to the insertion of the corresponding pile into the soil. The radial pile driving stress is the radial stress formed at the corresponding location in the corresponding iteration due to the energy transmission of the pile driving of the corresponding pile. i is a positive integer, and when i=1, the soil density corresponding to the target location in the (i-1)th iteration comes from the first density information. Based on the radial environmental stress and radial pile driving stress corresponding to the target position in the i-th iteration, the soil density corresponding to the target position in the (i-1)-th iteration is optimized to obtain the soil density corresponding to the target position in the i-th iteration.

2. The method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method according to claim 1, characterized in that, The steps for obtaining the radial environmental stress corresponding to the target position in the i-th iteration include: Based on the column radius of the pile corresponding to the i-th iteration, the interval between the target position and the settlement position corresponding to the i-th iteration, and the median particle size of the sand at the target position, the compaction influence factor corresponding to the target position in the i-th iteration is determined, where the compaction influence factor indicates the degree to which the corresponding position is affected by the corresponding pile. Based on the radial environmental stress corresponding to the target position in the (i-1)th iteration, the force efficiency value corresponding to the target position in the ith iteration, and the compaction influence factor corresponding to the target position in the ith iteration, the radial environmental stress corresponding to the target position in the ith iteration is determined. The force efficiency value indicates the radial environmental stress transmission efficiency at the corresponding position in the corresponding iteration. When i=1, the radial environmental stress corresponding to the target position in the (i-1)th iteration is determined based on the first compaction information.

3. The method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method according to claim 2, characterized in that, The steps for determining the compaction influence factor corresponding to the target location in the i-th iteration, based on the pile radius corresponding to the i-th iteration, the interval between the target location and the settlement location corresponding to the i-th iteration, and the median particle size of the sand at the target location, include: Analyze the difference between the column radius of the pile corresponding to the i-th iteration and the median particle size of the sand at the target location to obtain the pile-particle difference value corresponding to the target location in the i-th iteration; Based on the pile-particle difference value corresponding to the target position in the i-th iteration and the interval distance between the target position and the sinking position corresponding to the i-th iteration, the compaction influence factor corresponding to the target position in the i-th iteration is determined. The compaction influence factor is positively correlated with the corresponding pile-particle difference value and negatively correlated with the corresponding interval distance.

4. The method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method according to claim 2, characterized in that, The force efficiency value is determined based on the internal friction angle at the corresponding position under the corresponding iteration, and the internal friction angle at the target position under the i-th iteration is determined based on the soil density corresponding to the target position in the (i-1)-th iteration.

5. The method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method according to claim 4, characterized in that, The steps for determining the radial environmental stress corresponding to the target position in the i-th iteration based on the radial environmental stress corresponding to the target position in the (i-1)-th iteration, the force efficiency value corresponding to the target position in the i-th iteration, and the compaction influence factor corresponding to the target position in the i-th iteration include: Based on the force efficiency value corresponding to the target position in the i-th iteration, the compaction influence factor corresponding to the target position in the i-th iteration is nonlinearly modulated to obtain the stress correction coefficient corresponding to the target position in the i-th iteration. Here, the compaction influence factor corresponding to the target position in the i-th iteration is greater than 1, and the force efficiency value corresponding to the target position in the i-th iteration is also greater than 1. Calculate the product of the stress correction coefficient corresponding to the target position in the i-th iteration and the radial environmental stress corresponding to the target position in the (i-1)-th iteration to obtain the radial environmental stress corresponding to the target position in the i-th iteration.

6. The method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method according to claim 1, characterized in that, The steps for obtaining the radial pile driving stress corresponding to the target position in the i-th iteration include: Based on the interval between the target location and the sinking location corresponding to the i-th iteration, the column radius of the pile corresponding to the i-th iteration, the shear parameters of the target location in the i-th iteration, and the soil density corresponding to the target location in the (i-1)-th iteration, the energy conversion rate of the target location in the i-th iteration is determined. The energy conversion rate indicates the efficiency of the pile driving energy in the corresponding iteration in converting into radial stress at the corresponding location, and the shear parameters indicate the maximum shear strength of the unit effective normal stress at the corresponding location in the corresponding iteration. Based on the energy conversion rate at the target location in the i-th iteration and the pile driving energy corresponding to the i-th iteration, the radial pile driving stress corresponding to the target location in the i-th iteration is determined.

7. The method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method according to claim 6, characterized in that, The shear resistance parameter at the target location in the i-th iteration is determined based on the tangent of the internal friction angle at the target location in the i-th iteration, and the internal friction angle at the target location in the i-th iteration is determined based on the soil density corresponding to the target location in the (i-1)-th iteration.

8. The method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method according to claim 6, characterized in that, The energy conversion rate is negatively correlated with the corresponding interval distance, positively correlated with the corresponding column radius, positively correlated with the corresponding shear resistance parameter, and positively correlated with the corresponding soil density.

9. The method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method according to claim 1, characterized in that, The steps for optimizing the soil density at the target location in the (i-1)th iteration based on the radial environmental stress and radial pile driving stress at the target location in the i-th iteration, to obtain the soil density at the target location in the i-th iteration, include: Based on the radial environmental stress and radial pile driving stress corresponding to the target position in the i-th iteration, determine the radial comprehensive stress corresponding to the target position in the i-th iteration; Analyze the difference between the radial composite stress and the radial reference stress corresponding to the target position in the i-th iteration to determine the radial stress intensity corresponding to the target position in the i-th iteration; Based on the radial stress intensity corresponding to the target position in the i-th iteration, the soil density corresponding to the target position in the (i-1)-th iteration is optimized to obtain the soil density corresponding to the target position in the i-th iteration.

10. The method for analyzing the bearing capacity of prestressed concrete piles based on the finite element method according to claim 9, characterized in that, The steps for optimizing the soil density at the target location in the (i-1)th iteration based on the radial stress intensity at the target location in the i-th iteration to obtain the soil density at the target location in the i-th iteration include: The radial stress intensity and redundant porosity at the target location in the i-th iteration are used to determine the porosity change index at the target location in the i-th iteration. The redundant porosity at the target location in the i-th iteration indicates the difficulty of closing the soil pores at the target location in the i-th iteration. The void ratio change index corresponding to the target location in the i-th iteration is used to amplify the soil density corresponding to the target location in the (i-1)-th iteration, so as to obtain the soil density corresponding to the target location in the i-th iteration.

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