Method and system for determining vertical ultimate bearing capacity of wharf foundation pile

Abstract

The invention provides a method and system for determining the vertical ultimate bearing capacity of a wharf foundation pile, and relates to the technical field of foundation pile bearing capacity determination.The method comprises the steps that firstly, pore pressure static sounding test data at the design position of the foundation pile and key mechanical parameters of all soil layers are obtained, and the initial comprehensive bearing rigidity and the initial vertical ultimate bearing capacity of the foundation pile are determined; when a random event occurs, impact types are classified, feature data are obtained, and the initial comprehensive bearing rigidity is updated based on the data; damage component data such as cyclic load, horizontal load, scouring and corrosion are obtained, and a multi-mechanism coupled bearing rigidity damage dynamic model is constructed; and finally, correcting the updated comprehensive bearing stiffness based on the model to obtain the real-time comprehensive bearing stiffness, and updating the initial vertical ultimate bearing capacity by using the real-time comprehensive bearing stiffness to obtain the real-time vertical ultimate bearing capacity. The method can accurately evaluate the bearing performance of the wharf foundation pile in real time, and provides technical support for safe operation of a wharf structure.

Description

Technical Field

[0001] This invention relates to the field of pile bearing capacity measurement technology, specifically a method and system for determining the vertical ultimate bearing capacity of wharf piles. Background Technology

[0002] As a crucial foundation component of marine engineering structures, the accurate determination of the vertical ultimate bearing capacity of wharf foundation piles is of great significance for ensuring the safety of wharf structures. With the continuous expansion of marine engineering construction scale and the increasing complexity of service environments, the precise assessment of foundation pile bearing capacity has become an important research topic in the field of geotechnical engineering.

[0003] Currently, the determination of the vertical ultimate bearing capacity of foundation piles mainly relies on geological survey data and static cone penetration tests. Prior art (CN120925548A) discloses a method for estimating the vertical bearing capacity of steel pipe piles. This method obtains experimental data through static cone penetration tests and performs normalization processing, calculating the side friction and end resistance of the steel pipe pile based on soil mechanical parameters. Prior art (CN113434930A) relates to a method for calculating the vertical ultimate bearing capacity of foundation piles, determining the vertical ultimate bearing capacity of the pile by calculating the cumulative ultimate side friction of the pile body traversing various karst caves and embedded rock sections. Prior art (CN110029692A) provides a method for determining the time-dependent bearing capacity of single piles in soft soil based on SCPTu probe test values, reflecting the change in pile side bearing capacity over time after pile formation. Prior art with publication number CN119203746A discloses a method for predicting the bearing capacity of a single pile in offshore wind power, which uses measured data from static cone penetration tests to determine the side skin friction and unit end resistance of the single pile in different soil strata. Prior art with publication number CN102587426A discloses an analytical method for estimating the bearing capacity of a pile foundation based on cone penetration testing, which establishes empirical formulas by measuring the cone tip resistance and side skin friction corresponding to different relative deformations between the probe and the soil.

[0004] However, existing methods for determining the ultimate vertical bearing capacity of wharf foundation piles still have significant technical shortcomings. First, traditional methods primarily rely on static geological survey data from the initial construction phase to determine fixed bearing capacity values, failing to reflect the dynamic evolution of bearing capacity due to environmental changes and load history during long-term service, exhibiting clear limitations in static assessment. Second, existing bearing capacity calculation methods are overly simplistic in their consideration of damage mechanisms, focusing mainly on static soil parameters. They struggle to effectively quantify the coupled degradation effects of multiple damage mechanisms, such as cyclic loading, horizontal loading, ocean current erosion, and seawater corrosion, on bearing capacity, thus failing to accurately reflect the true degradation patterns of pile bearing capacity in marine environments. Finally, when wharf structures encounter random extreme events such as ship collisions or earthquakes, the support stiffness of the foundation piles undergoes abrupt changes. Existing methods lack the ability to dynamically update the bearing capacity based on event characteristics in a timely manner, resulting in significant lag in safety assessments and failing to meet the engineering requirements for real-time safety monitoring of wharf structures.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a method and system for determining the vertical ultimate bearing capacity of wharf foundation piles, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for determining the ultimate vertical bearing capacity of wharf foundation piles, comprising the following steps: S1: Obtain the test data of static cone penetration test at the design location of the foundation pile and the key mechanical parameters of each soil layer. Based on the initial test data of static cone penetration test and the key mechanical parameters of each soil layer, determine the initial comprehensive support stiffness and initial vertical ultimate bearing capacity of the foundation pile. S2: When a random event occurs, the impact type of the random event is classified and the characteristic data of the random extreme event is obtained. Based on the characteristic data of the random extreme event, an event intensity index is constructed. The damage sensitivity coefficient is calibrated by finite element method. The initial comprehensive support stiffness is updated based on the event intensity index and the damage sensitivity coefficient. S3: Obtain historical service data of the foundation piles up to the time of the random event, introduce four damage mechanisms: cyclic load, horizontal load, scour and corrosion, establish damage change rate function for each mechanism, couple each damage component through differential equations, and add inter-mechanism coupling terms to construct a support stiffness damage dynamic model. S4: Based on the support stiffness damage dynamics model, solve the total damage factor at the current moment, correct the updated comprehensive support stiffness, obtain the real-time comprehensive support stiffness, update the initial vertical ultimate bearing capacity using the real-time comprehensive support stiffness, and obtain the real-time vertical ultimate bearing capacity.

[0008] Furthermore, the initial test data of the pore pressure static cone penetration test includes: continuous data on the changes in cone tip resistance, sidewall friction resistance, and pore water pressure with depth; and the total overburden stress and effective overburden stress at each test depth are calculated, where the total overburden stress is the total weight of the soil column above the test depth, and the effective overburden stress is the difference between the total overburden stress and the pore water pressure at the test depth; the cone tip resistance and sidewall friction resistance are corrected for probe cross-section inequivalence and pore water pressure effects to obtain the corrected cone tip resistance and corrected sidewall friction resistance; normalization is performed to obtain the normalized cone tip resistance and friction ratio; the total overburden stress is subtracted from the corrected cone tip resistance to obtain the difference, and then the difference is divided by the effective overburden stress to obtain the normalized cone tip resistance; Subtract the total overburden stress from the corrected cone tip resistance to obtain the difference. Then divide the corrected sidewall friction resistance by this difference and multiply the result by 100% to obtain the normalized friction ratio, expressed as a percentage.

[0009] Furthermore, based on the normalized cone tip resistance and normalized friction ratio, multiple soil layers are divided at the design location of the foundation piles in the soil behavior type chart, and the key mechanical parameters of each soil layer are obtained, including: soil type, initial small strain shear modulus and reference shear strain of each soil layer. Different inversion formulas are used to obtain the initial small strain shear modulus of each soil layer for different soil types; among them, for sandy soil layers, the initial small strain shear modulus of sandy soil layers is obtained by combining the modified cone tip resistance with the empirical coefficient of sandy soil layers. For clay soil layers, the undrained shear strength of the soil layer is derived from the initial test data of pore pressure static cone penetration test. The initial small strain shear modulus of the clay soil layer is obtained based on the undrained shear strength and the empirical coefficient of the clay soil layer. The reference shear strain is determined for each soil layer according to the soil classification through indoor bending element and resonant column tests.

[0010] Furthermore, the pile body is discretized into several units. The bearing stiffness of the soil layer in each unit is characterized by the initial small strain shear modulus and reference shear strain value of each soil layer through the initial tangential stiffness of the nonlinear spring model. The bearing stiffness of all units along the entire pile length is integrated and synthesized to obtain the initial comprehensive bearing stiffness of the pile. Based on the initial test data of pore pressure static penetration, the ultimate resistance at the pile tip and the total ultimate frictional resistance on the pile side are calculated respectively. The sum of the two is the initial vertical ultimate bearing capacity.

[0011] Furthermore, when a random event occurs, the characteristic data of the random extreme event include: impact type, peak load, peak acceleration, duration, and effective parameter mass of the foundation pile; among them, the impact type of the random event is classified into: vibration event and impact event; an update function based on the characteristic data of the extreme event is established, a comprehensive support stiffness update coefficient is designed, and the initial comprehensive support stiffness is updated; Furthermore, the impact types include impact events and vibration events, and reference intensity indices are set for different impact types of events; for impact events, the event intensity index of the impact event is determined by the peak load and duration in the extreme event characteristic data, specifically: the product of the peak load and duration divided by the product of the effective parameter mass of the foundation pile and the gravitational acceleration is the event intensity index value of the impact event.

[0012] For vibration events, the event intensity index of the vibration event is obtained by integrating the peak acceleration in the extreme event characteristic data, and the event intensity index value of the vibration event is obtained based on the reference intensity index corresponding to the vibration event, specifically the integral of the peak acceleration over the duration.

[0013] Furthermore, the initial comprehensive support stiffness is updated based on the characteristic data of random extreme events. Specifically, the damage sensitivity coefficient of the comprehensive support stiffness is calibrated through finite element numerical simulation. The comprehensive support stiffness update coefficient is determined by combining the obtained event strength index value, the corresponding reference strength index, and the damage sensitivity coefficient of the support stiffness. Specifically, the event strength index value is divided by the reference strength index to obtain a ratio, this ratio is multiplied by the damage sensitivity coefficient, and the negative of the result of this step is taken. A natural constant is constructed using the above results as an exponent. The updated comprehensive support stiffness coefficient is obtained by multiplying the updated comprehensive support stiffness by the initial comprehensive support stiffness using the exponential function value with base 0.

[0014] Furthermore, historical service data of the foundation piles up to the time of the random event are obtained, and four damage mechanisms—cyclic load, horizontal load, scour, and corrosion—are introduced. Specifically, damage change rate functions for each mechanism are established, and data on cyclic load damage components, horizontal load damage components, scour damage components, and corrosion damage components are obtained. The cyclic load damage component is constructed by introducing historical data on the number of cycles and corresponding stress ratios of the soil in which each discrete unit of the pile body is located up to the time of the random extreme event, to obtain equivalent cycle number and equivalent cyclic stress ratio. Based on the equivalent cycle number and equivalent cyclic stress ratio, a power function-form dynamic equation is used to construct the cyclic load damage change rate function to obtain the cyclic load damage component. The horizontal load damage component is obtained by acquiring the maximum bending moment of the pile and the proportion of the pile-soil void area up to the occurrence of the random extreme event, setting the pile yield bending moment and horizontal load damage parameters, constructing the horizontal load damage change rate function, and obtaining the horizontal load damage component. By introducing the distribution function of the time-varying scour depth and pile diameter along the depth up to the occurrence of the random extreme event, and setting the inherent geometric parameter of the total side surface area of ​​the pile, a scour damage change rate function is constructed based on the above parameters to obtain the scour damage components. The corrosion damage is obtained by acquiring the time-varying corrosion rate up to the current moment, the corrosion initiation time, and the distribution function of the initial diameter of the pile along the depth, and by setting the inherent geometric parameter of the initial total cross-sectional area of ​​the pile, constructing the corrosion damage change rate function, and obtaining the corrosion damage components.

[0015] Furthermore, based on the support stiffness damage dynamics model, the total damage factor at the current moment is solved, and the updated comprehensive support stiffness is corrected. Specifically, the total damage factor at the current moment is obtained by numerically integrating the support stiffness damage dynamics model based on the above-mentioned multi-mechanism damage coupling when a random extreme event occurs. The difference between 1 and the total damage factor is multiplied by the updated comprehensive support stiffness to obtain the real-time comprehensive support stiffness. Based on the ratio of the real-time comprehensive support stiffness to the initial comprehensive support stiffness, a correction coefficient is set that combines the nonlinear relationship between the comprehensive support stiffness and the vertical ultimate bearing capacity. The real-time vertical ultimate bearing capacity is determined by multiplying the ratio of the real-time comprehensive support stiffness to the initial comprehensive support stiffness by the initial vertical ultimate bearing capacity and then by the correction coefficient.

[0016] The present invention also provides a system for determining the vertical ultimate bearing capacity of wharf foundation piles. This system is used to execute the aforementioned method for determining the vertical ultimate bearing capacity of wharf foundation piles, and includes: The initial parameter accurate inversion module is used to obtain the test data of pore pressure static cone penetration test at the design location of the foundation pile and the key mechanical parameters of each soil layer. Based on the initial test data of pore pressure static cone penetration test and the key mechanical parameters of each soil layer, the initial comprehensive support stiffness and initial vertical ultimate bearing capacity of the foundation pile are determined. The extreme event impact response update module is used to classify the impact type of random events and obtain random extreme event characteristic data when random events occur. Based on the random extreme event characteristic data, an event intensity index is constructed, the damage sensitivity coefficient is calibrated through finite element method, and the initial comprehensive support stiffness is updated based on the event intensity index and the damage sensitivity coefficient. The multi-mechanism damage dynamics construction module is used to obtain the service history data of the foundation pile up to the time of the random event. It introduces four damage mechanisms: cyclic load, horizontal load, scour and corrosion, establishes the damage change rate function of each mechanism, couples each damage component through differential equations, and adds inter-mechanism coupling terms to construct a support stiffness damage dynamics model. The real-time bearing capacity dynamic correction module is used to solve the total damage factor at the current moment based on the support stiffness damage dynamics model, correct the updated comprehensive support stiffness, obtain the real-time comprehensive support stiffness, and use the real-time comprehensive support stiffness to update the initial vertical ultimate bearing capacity to obtain the real-time vertical ultimate bearing capacity.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: By constructing a dynamic update mechanism based on pore pressure static cone penetration test data, the vertical ultimate bearing capacity of the foundation pile can be dynamically updated according to real-time monitoring data and the triggering of random extreme events, overcoming the limitations of traditional methods based on fixed bearing capacity values ​​at the initial stage of construction; by establishing a multi-mechanism coupled damage dynamics model, four damage mechanisms—cyclic load, horizontal load, scour, and corrosion—are coupled into a unified dynamic model for the first time, solving the problem of the single mechanism in existing bearing capacity calculation methods; by establishing a stiffness update function based on event characteristics, the instantaneous impact of random extreme events such as ship collisions and earthquakes on the bearing capacity of the foundation pile can be quantified, solving the technical defect of existing methods that cannot update the bearing capacity in a timely manner based on event characteristics. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall method flow of the present invention; Figure 2 This is a time history data diagram of damage bearing capacity according to an embodiment of the present invention; Figure 3 This is a block diagram of the system module structure of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0020] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] Example: Please see Figure 1 The present invention provides a technical solution: A method for determining the ultimate vertical bearing capacity of wharf foundation piles, comprising the following steps: S1: Obtain the test data of static cone penetration test at the design location of the foundation pile and the key mechanical parameters of each soil layer. Based on the initial test data of static cone penetration test and the key mechanical parameters of each soil layer, determine the initial comprehensive support stiffness and initial vertical ultimate bearing capacity of the foundation pile. In this embodiment, the initial test data of the pore pressure static cone penetration test include continuous data on the changes in cone tip resistance, sidewall friction, and pore water pressure with depth. The total overburden stress and effective overburden stress at each test depth are calculated, where the total overburden stress is the total weight of the soil column above the test depth, and the effective overburden stress is the difference between the total overburden stress and the pore water pressure at the test depth. The cone tip resistance and sidewall friction are corrected for probe cross-section inequivalence and pore water pressure effects to obtain the corrected cone tip resistance and corrected sidewall friction. Normalization is performed to eliminate the influence of the effective overburden stress, obtaining the normalized cone tip resistance and friction ratio. The total overburden stress is subtracted from the corrected cone tip resistance to obtain the difference, which is then divided by the effective overburden stress to obtain the normalized cone tip resistance. The specific formula is as follows: in, To normalize the cone tip resistance, The corrected cone tip resistance, For the total overburden stress, To effectively reduce overburden stress, The pore water pressure is normalized; the cone tip resistance is normalized to eliminate the influence of overburden stress on the cone tip resistance, making the strength of soil layers at different depths comparable and facilitating soil type identification. Represents the supercone tip drag. This represents the effective stress, and the ratio of the two can normalize the stress level. If... Increase (depth increases), and If it remains unchanged, then Reducing the value may underestimate the soil strength; if Decrease (e.g., increase pore pressure). Increasing the value might overestimate the intensity; normalization is precisely to correct for these effects.

[0022] The difference is obtained by subtracting the total overburden stress from the corrected cone tip resistance. Then, the corrected sidewall friction is divided by this difference, and the result is multiplied by 100% to obtain the normalized friction ratio, expressed as a percentage. The specific formula is as follows: in, To normalize the friction ratio, This represents the corrected sidewall frictional resistance. The friction ratio is an important indicator for differentiating soil types. Using the super-cone tip resistance in the denominator instead of the total cone tip resistance further eliminates the influence of stress; the numerator... The sidewall friction is the denominator. The net cone tip resistance, combined with the other two, can better reflect the characteristics of soil particles; Increase An increase indicates that the soil is becoming more cohesive; Increase A decrease indicates that the soil is becoming sandy. In this embodiment, a static cone penetration test was conducted at the designed location of a wharf foundation pile, and the raw data obtained are shown in Table 1 below: Table 1: Initial Test Data of Pore Pressure Static Cone Penetration Test This table records the cone tip resistance, sidewall friction, and pore water pressure at depths from 1m to 19m, showing their variation with depth. The data indicates that with increasing depth, the cone tip resistance gradually increases from 0.8MPa to 18.0MPa, the sidewall friction increases from 30kPa to 300kPa, and the pore water pressure linearly increases from 10kPa to 190kPa, reflecting the typical characteristics of the soil transitioning from shallow soft soil to deep dense sand. These in-situ test data form the basis for subsequent normalization, soil layer division, and mechanical parameter inversion; their accuracy and continuity directly determine the reliability of the entire evaluation system. Based on the initial test data from the pore pressure static cone penetration test in Table 1, after correction and normalization, the normalized cone tip resistance and normalized friction ratio at each depth are obtained, as shown in Table 2 below. Table 2: Normalized Cone Tip Resistance and Friction Ratio Data The table shows the formulas used. and The calculated normalized parameters. At depths of 0–10 m, Values ​​range from 25.5 to 97.8. Between 3.8% and 4.6%, it conforms to the characteristics of clay; at a depth of 10–20m, It surged to 53.3-103.8. The modulus decreased to 1.7%–2.1%, indicating sandy soil. This result eliminated the influence of overlying stress, making soils at different depths comparable, providing key input for subsequent soil layering based on SBT charts, and also laying the foundation for inverting small-strain shear modulus.

[0023] In this embodiment, based on the normalized cone tip resistance and normalized friction ratio, multiple soil layers are divided at the design location of the foundation piles using a soil behavior type chart. and The Soil Behaviour Type (SBT) chart classifies soil types, such as clay, silt, and sand; and according to... The inflection point and magnitude change of the curve, combined with Features, accurately delineate soil layer interfaces, determine the depth range of each soil layer, and obtain key mechanical parameters of each soil layer, including: soil type, initial small strain shear modulus and reference shear strain of each soil layer. Different inversion formulas are used to obtain the initial small-strain shear modulus of each soil layer for different soil types. Specifically, for sandy soil layers, the initial small-strain shear modulus is obtained by combining a modified cone tip resistance with empirical coefficients for sandy soil layers. The specific formula is as follows: For clay soil layers, the undrained shear strength of the soil layer is derived from the initial test data of pore pressure static cone penetration testing. Based on the undrained shear strength and empirical coefficients for clay soil layers, the initial small-strain shear modulus of the clay soil layer is obtained. The specific formula is as follows: in, For the first Initial small strain shear modulus of soil layer This is an empirical coefficient for sandy soil layers. For the first Cone tip resistance after soil layer correction For the first The total overburden stress at the midpoint of the soil layer, For the first Effective overburden stress at the midpoint of the soil layer This is an empirical coefficient for clay soil layers. For the first Undrained shear strength of soil layers This is an empirical coefficient.

[0024] Sandy soil layers ,in It reflects the net resistance of soil to penetration and is positively correlated with stiffness; It reflects the effective confining pressure and has a significant impact on the modulus of sand. The regional characteristics were reflected through experimental calibration. (Increase) Directly increase the modulus; increase This enhances the effect of net cone tip resistance; increases This enhances the effect of effective stress. (Clay soil type) , It can be reliably estimated from the initial test data of pore pressure static cone penetration testing. This is an empirical proportionality coefficient. The larger the modulus, the higher the modulus, indicating greater soil rigidity. Reference shear strain is determined based on soil classification, and the reference shear strain value for each soil layer is calibrated using indoor bending element and resonant column tests. In this embodiment's simulation experiment, soil layers are divided according to normalized parameters, and the initial small-strain shear modulus of each soil layer is inverted. and reference shear strain As shown in Table 3 below: Table 3: Soil Layer Division and Mechanical Parameter Data Table The table divides the 0–20m pile body range into two soil layers: 0–10m is a clay layer with an initial small strain shear modulus. =10 MPa, reference shear strain =0.02; 10–20m is a sandy soil layer, =50 MPa =0.01. This value was obtained by inversion from the initial test data of the static cone penetration test using an empirical formula. These parameters, calibrated through laboratory tests based on soil type, are central to pile-soil interaction analysis. They are directly used in subsequent pile element stiffness calculations and determine the accuracy of the initial comprehensive support stiffness.

[0025] The pile body is discretized into several elements. The support stiffness of the soil layer in which each element is located is characterized by the initial small-strain shear modulus and reference shear strain value of each soil layer through the initial tangential stiffness of a nonlinear spring model. The support stiffness of all elements along the entire pile length is integrated and synthesized to obtain the initial comprehensive support stiffness of the pile. In this embodiment, for the soil layer... In the pile element, its axial (vertical) support stiffness can be characterized as a nonlinear spring model. Its initial tangential stiffness is proportional to the initial small-strain shear modulus and inversely proportional to the nonlinear scale represented by the reference shear strain value corresponding to the soil layer. It is also related to the geometric dimensions of the pile element. The pile body element in the equation has the following formula: in, For the first Axial (vertical) support stiffness of pile units in soil layers. For the first The length of the pile unit in the soil layer, For the first The radius of the pile element in the soil layer. To affect the radius, For the first The reference shear strain value of the soil layer is used; the initial comprehensive support stiffness of the pile is obtained by integrating the axial (vertical) support stiffness of all pile elements using elastic theory. Based on the cylindrical expansion model of elastic theory, the shear deformation of the soil along the pile is simplified to an axisymmetric problem, and the geometric diffusion is described by logarithmic terms; a reference shear strain is introduced. Characterizing soil nonlinearity. In the simulation experiment of this embodiment, the pile radius... =0.6 m, element length =2m, radius of influence =10 m, =2.81; The pile body is discretized into 10 elements, and the axial support stiffness of each element is calculated based on the soil parameters. The initial comprehensive support stiffness is then synthesized as shown in Table 4 below: Table 4: Stiffness and Initial Composite Stiffness Data of Pile Element The table lists the calculated stiffness of each 2m long pile element. The stiffness of each clay layer element is 2.236 × 10⁻⁶. 6 kN / m, the stiffness of all sand layer elements is 22.36×10 kN / m. 6 kN / m. The initial comprehensive support stiffness is obtained by summing, and this stiffness is based on... The calculation comprehensively considers the soil's small strain modulus, nonlinear scale, and geometric dimensions, providing a comprehensive characterization of the initial vertical deformation resistance of the foundation pile and offering a benchmark for subsequent bearing capacity assessment.

[0026] In this embodiment, the initial comprehensive support stiffness of the foundation pile is calculated as follows: Based on the initial test data from the static cone penetration test, the ultimate resistance at the pile tip and the total ultimate skin friction along the pile side were calculated separately. The sum of the two is the initial vertical ultimate bearing capacity. The formula for calculating the total ultimate skin friction along the pile side is as follows: in, For the first The ultimate unit lateral resistance of a pile element in soil layer. No. The lateral surface area of ​​the pile element in the soil layer; the formula for calculating the ultimate resistance at the pile tip is as follows: in, The ultimate end resistance is determined by the soil layers near the pile tip. The profile was obtained by averaging and correcting the formula. The area at the pile tip is used. Following the classic method of directly estimating the pile bearing capacity using initial test data from static cone penetration testing, the side resistance is directly calculated from the sidewall friction data of the initial static cone penetration testing. The end resistance is obtained by averaging the cone tip resistance near the pile tip. The sum of the ultimate end resistance and the total ultimate side friction resistance is the initial vertical ultimate bearing capacity. In this simulation experiment, the average area of ​​the clay layer is... The average sandy soil layer Surface area of ​​unit side , , Therefore there is , That is, the initial vertical ultimate bearing capacity is obtained. .

[0027] This step, based on in-situ static cone penetration testing (CPPT), directly obtains the mechanical parameters of continuous soil layers, avoiding the disturbances and discreteness of traditional drilling sampling and laboratory tests. Normalization eliminates the influence of overlying stress, and soil layers are precisely delineated using soil behavior type charts. For different soil types, empirical formulas are used to invert the small-strain shear modulus, providing high-precision input for subsequent stiffness calculations. Discrete pile elements and nonlinear spring models meticulously reflect pile-soil interactions, making the initial comprehensive support stiffness calculation more realistic. This improves the accuracy of initial bearing capacity assessment and reduces exploration costs and workload; refined soil layer delineation and parameter inversion lay a reliable foundation for subsequent dynamic assessments. Simultaneously, this step provides the baseline state for the entire method: initial comprehensive support stiffness and initial vertical ultimate bearing capacity. All subsequent updates and corrections are based on this, and its accuracy directly affects the reliability of the final results.

[0028] S2: When a random event occurs, the impact type of the random event is classified and the characteristic data of the random extreme event is obtained. The initial comprehensive support stiffness is updated based on the characteristic data of the random extreme event. In this embodiment, when a random event occurs, the impact type of the random event is classified into: vibration event and impact event; the characteristic data of random extreme events include: impact type, peak load, peak acceleration, duration, and effective parameter mass of the foundation pile; an update function based on the characteristic data of extreme events is established, a comprehensive support stiffness update coefficient is designed, and the initial comprehensive support stiffness is updated; The impact types include impact events and vibration events, and reference intensity indices are set for different impact types. For impact events, the event intensity index is determined by the peak load and duration in the extreme event characteristic data. Specifically, the event intensity index value is obtained by dividing the product of the peak load and duration by the product of the effective pile mass and gravitational acceleration. In this embodiment, the specific formula is as follows: in, This refers to the event intensity index value of the impact event. For peak load, For duration, The length of the pile above the soil layer. This is the acceleration due to gravity; this formula is derived from... and The product represents the impact energy, divided by and The product is normalized; where, divided by The physical meaning is that, for the same total impulse, a longer free pile length results in less energy absorbed per unit pile length, thus reducing the degree of damage; therefore, the index... The smaller the value, the lower the intensity of the event and the less potential damage to the foundation pile; this clarifies the physical meaning and directionality.

[0029] For vibration events, the event intensity index is obtained by integrating the peak acceleration from the extreme event characteristic data. Then, based on the corresponding reference intensity index, specifically the integral of the peak acceleration over its duration, the event intensity index value is obtained, as shown in the following formula: in, This refers to the event intensity index value of the vibration event. represents the peak acceleration. This formula uses the square integral of acceleration to reflect the vibrational energy; where... The square is related to energy density; the longer the integration time or the larger the amplitude, the larger the index.

[0030] In this embodiment, the initial comprehensive support stiffness is updated based on random extreme event characteristic data. Specifically, the damage sensitivity coefficient of the comprehensive support stiffness is calibrated through finite element numerical simulation. The comprehensive support stiffness update coefficient is determined by combining the obtained event strength index value, the corresponding reference strength index, and the damage sensitivity coefficient of the support stiffness. Specifically, the event strength index value is divided by the reference strength index to obtain a ratio, this ratio is multiplied by the damage sensitivity coefficient, and the negative of the result of this step is taken. A natural constant is constructed using the above result as an exponent. The updated coefficient for comprehensive support stiffness is obtained by using the exponential function value with base 1; the specific formula is as follows: in, To update the overall support stiffness coefficient, The damage sensitivity coefficient, This is the event intensity index value. This serves as a reference intensity indicator for the event. The updated comprehensive support stiffness is obtained by multiplying the comprehensive support stiffness update factor by the initial comprehensive support stiffness: This represents the initial comprehensive support stiffness of the foundation piles. This is the updated overall support stiffness. The larger the value, the greater the reduction for the same relative intensity; the greater the relative intensity, the greater the reduction. This formula, through an exponential function, ensures that the reduction coefficient monotonically decreases in the range [0,1], and that there is no reduction when the event intensity is zero, and it approaches complete failure when the intensity is very high.

[0031] In this simulation experiment, a collision event occurs, and the characteristic data of the random extreme event include: Duration The length of the pile above the soil layer ,get In the simulation experiment , Therefore, based on the above formula, we obtain The updated comprehensive support stiffness is obtained by multiplying the comprehensive support stiffness update factor by the initial comprehensive support stiffness. .

[0032] This step can promptly reflect the damage caused by random extreme events, providing a more accurate initial state for subsequent long-term damage accumulation. Traditional methods usually ignore the instantaneous impact of random extreme events on the bearing capacity of piles, or only make qualitative judgments. This step transforms random extreme events into quantitative stiffness reductions through event classification, strength index quantification, and exponential update coefficients, achieving real-time dynamic updates of the pile condition.

[0033] S3: Obtain historical service data of the foundation piles up to the time of the random event, introduce four damage mechanisms: cyclic load, horizontal load, scour and corrosion, establish damage change rate function for each mechanism, couple each damage component through differential equations, and add inter-mechanism coupling terms to construct a support stiffness damage dynamic model. In this embodiment, historical service data of the foundation pile up to the time of the random event is acquired, including: number of cyclic loads, horizontal load history, scour depth record, and corrosion time. Four damage mechanisms are introduced: cyclic load, horizontal load, scour, and corrosion. Specifically, damage change rate functions for each mechanism are established to obtain data for cyclic load damage components, horizontal load damage components, scour damage components, and corrosion damage components. The cyclic load damage component is constructed by introducing historical data on the number of cycles and corresponding stress ratios of the soil in which each discrete unit of the pile body is located up to the time of the random extreme event, to construct equivalent number of cycles and equivalent cyclic stress ratio. Based on the equivalent number of cycles and equivalent cyclic stress ratio, a power-law dynamic equation is used to construct the cyclic load damage change rate function to obtain the cyclic load damage components. The specific formula is as follows: in, , , Empirical parameters for cyclic softening of soil. The equivalent cyclic stress ratio, Deadline The equivalent number of loops, This represents the cyclic load damage component. Rainflow counting was performed on the time histories of cyclic shear stress in the soil at each unit of the pile, combined with data obtained from indoor tests. curve, If the soil reaches the specified failure standard at this amplitude, calculate the equivalent number of cycles. And the corresponding equivalent cyclic stress ratio. Based on the fatigue cumulative damage theory, the damage rate is expressed as a function of the current equivalent cyclic stress ratio, the equivalent number of cycles, and the current damage using a power function, which can reflect the nonlinear cumulative characteristics. and This comprehensively reflects the load level and the number of cycles. The rate of damage slows down as it approaches 1. Increase the size of the area, and the damage rate will increase. As the stress ratio increases, its effect becomes more significant. As the number of cycles increases, the effect of higher cycle counts becomes more significant. A value greater than 0 causes the damage rate to decrease as damage increases. In this embodiment... , , , , .

[0034] The horizontal load damage component is obtained by acquiring the maximum bending moment of the pile and the proportion of the pile-soil void area up to the occurrence of the random extreme event, and by setting the pile yield bending moment and horizontal load damage parameters, constructing a horizontal load damage change rate function, and obtaining the horizontal load damage component; the specific formula is as follows: in, For horizontal load damage components, These are empirical damage parameters for horizontal load damage. This represents the maximum value of the bending moment distribution along the depth of the pile. The yield moment of the pile section. The proportion of the pile-soil void area. It is a unit step function. This represents the moment when voiding begins. The purpose of this formula is to explain that horizontal loads cause bending moments in the pile, and plastic damage occurs when these moments exceed the yield moment. Simultaneously, pile-soil voiding exacerbates the damage, using the moment ratio and voiding ratio as driving factors. In this embodiment... , , , , .

[0035] By introducing the distribution functions of time-varying scour depth and pile diameter along the depth up to the occurrence of a random extreme event, and setting the inherent geometric parameter of the total side surface area of ​​the pile, a scour damage change rate function is constructed based on the above parameters to obtain the scour damage components; the specific formula is as follows: in, To flush away the damaged components, For scouring depth, This represents the initial total side surface area. Current scour depth Perimeter of the pile section at the location, This information is obtained through regular underwater topographic surveys and direct monitoring. The purpose of this formula is to reduce side friction by addressing the direct soil loss caused by scouring. The damage rate is proportional to the perimeter and scouring rate at the current scouring location, and is normalized using the total side surface area. In the simulation experiment of this embodiment, , .

[0036] The corrosion damage is described by obtaining the time-varying corrosion rate up to the current moment, the corrosion onset time, and the distribution function of the initial pile diameter along the depth. A corrosion damage change rate function is constructed by setting the inherent geometric parameter of the initial total cross-sectional area of ​​the pile, and the corrosion damage components are obtained. The specific formula is as follows: in, This is the corrosion damage component. This represents the initial total cross-sectional area of ​​the pile. For the total length of the pile, For depth coordinates, Let be the distribution function of the initial diameter of the pile along its depth. For time-varying corrosion rate, The event occurrence time is represented by the corrosion damage rate function, which describes the instantaneous rate at which corrosion damage accumulates over time. Its value depends on the integral of the product of the current remaining diameter and the corrosion rate along the pile length, reflecting the dynamic contribution of the corrosion process to the loss of the pile cross-section. In the simulation experiment of this embodiment, , As the diameter increases, the damage rate also increases; the longer the corrosion time, the smaller the current diameter, but the decrease in perimeter may slow down the rate of increase in area loss. The purpose of this formula is to consider the coupling between scour and horizontal load, where scour leads to increased voiding, thus amplifying the damage from horizontal load, and the coupling between corrosion and cyclic load, where corrosion reduces the cross-section and stress concentration occurs under cyclic load; the formula uses a product form, meaning that the existence of one mechanism amplifies the damage rate of the other mechanism.

[0037] A support stiffness damage dynamics model is constructed by coupling the damage components through differential equations and adding inter-mechanism coupling terms; the formula is as follows: in, The total damage factor, For inter-mechanism coupling terms, The coupling coefficient is determined through multi-field coupled numerical simulation or model tests. A larger coupling coefficient indicates stronger interaction and a faster increase in the total damage rate. Considering the coupling between scour and horizontal loads, scour exacerbates voiding, thus amplifying horizontal load damage; and the coupling between corrosion and cyclic loads, corrosion reduces the cross-section, leading to stress concentration under cyclic loads. A product form is used, meaning the presence of one mechanism amplifies the damage rate of another. Example simulation experiments, based on the coupling model of four damage mechanisms, calculate the damage factor and real-time bearing capacity year by year. The results are shown in Table 5 below: Table 5: Time History Data of Damage Evolution and Bearing Capacity This table presents the annual cyclic load damage, horizontal load damage, scour damage, corrosion damage, and their total damage factors from t=0 to t=10, along with the corresponding real-time comprehensive support stiffness and vertical ultimate bearing capacity. The data shows that the total damage factor increases from 0 to 0.844 annually, with cyclic load damage contributing the most (0.500), followed by scour damage (0.293) and corrosion damage (0.033). Horizontal load damage gradually becomes apparent in the later stages (0.016). This clearly demonstrates the performance degradation pattern of the foundation piles under the coupled effects of multiple mechanisms, providing a quantitative basis for wharf safety assessment and maintenance decisions.

[0038] S4: Based on the support stiffness damage dynamics model, solve the total damage factor at the current moment, correct the updated comprehensive support stiffness, obtain the real-time comprehensive support stiffness, update the initial vertical ultimate bearing capacity using the real-time comprehensive support stiffness, and obtain the real-time vertical ultimate bearing capacity.

[0039] In this embodiment, based on the support stiffness damage dynamics model, the total damage factor at the current moment is solved, and the updated comprehensive support stiffness is corrected. Specifically, the total damage factor at the current moment is obtained by numerically integrating the support stiffness damage dynamics model based on the above-mentioned multi-mechanism damage coupling when a random extreme event occurs. The difference between 1 and the total damage factor is multiplied by the updated comprehensive support stiffness to obtain the real-time comprehensive support stiffness; the formula is as follows: in, For the updated overall support stiffness, For real-time comprehensive support stiffness.

[0040] The ratio of real-time composite support stiffness to initial composite support stiffness is used to set a correction coefficient that combines the nonlinear relationship between composite support stiffness and vertical ultimate bearing capacity. The real-time vertical ultimate bearing capacity is determined by multiplying the ratio of real-time composite support stiffness to initial composite support stiffness by the initial vertical ultimate bearing capacity and then by the correction coefficient. The specific formula is as follows: in, This represents the initial vertical ultimate bearing capacity. For correction factor, This represents the real-time vertical ultimate bearing capacity. Since there is a positive, but not strictly linear, relationship between stiffness and bearing capacity, a correction factor is introduced. To adjust the linear approximation, in this embodiment Based on the total damage factor obtained in Table 5 and real-time integrated support stiffness The time history data of damage bearing capacity were obtained by performing the above calculations, as shown in Table 6 below: Table 6: Time History Data of Damage Bearing Capacity This embodiment is based on a coupled model of four damage mechanisms, considering cyclic loading, horizontal loading, erosion and corrosion damage, and introducing coupling terms. The total damage factor and the corresponding real-time stiffness and bearing capacity are obtained by year-by-year integration. The calculation results are as follows: Please see Figure 2 This reflects the total damage factor, as recorded in Table 6, increasing year by year from 0 to 0.844. The real-time stiffness correspondingly increased from 59.04 × 10⁻⁶. 6 kN / m decreased to 9.19×10 6 The bearing capacity decreased from 14459 kN to 2250 kN, a drop of 84.4%. This data clearly demonstrates the performance degradation pattern of the foundation piles under the coupled effects of multiple mechanisms, providing a quantitative basis for wharf safety assessment and maintenance decisions.

[0041] This step applies the total damage factor calculated by the damage model to the updated stiffness to obtain the real-time stiffness; then, a correction factor is introduced through the stiffness-bearing capacity relationship. The updated bearing capacity enables a quantitative assessment of the current state of the foundation piles. The correction factor takes into account the nonlinear relationship between stiffness and bearing capacity, making the update more accurate.

[0042] Please see Figure 3 The present invention also provides a system for determining the vertical ultimate bearing capacity of wharf foundation piles. This system is used to execute the aforementioned method for determining the vertical ultimate bearing capacity of wharf foundation piles, and includes: The initial parameter accurate inversion module is used to obtain the test data of pore pressure static cone penetration test at the design location of the foundation pile and the key mechanical parameters of each soil layer. Based on the initial test data of pore pressure static cone penetration test and the key mechanical parameters of each soil layer, the initial comprehensive support stiffness and initial vertical ultimate bearing capacity of the foundation pile are determined. The extreme event impact response update module is used to classify the impact type of random events and obtain random extreme event characteristic data when random events occur. Based on the random extreme event characteristic data, an event intensity index is constructed, the damage sensitivity coefficient is calibrated through finite element method, and the initial comprehensive support stiffness is updated based on the event intensity index and the damage sensitivity coefficient. The multi-mechanism damage dynamics construction module is used to obtain the service history data of the foundation pile up to the time of the random event. It introduces four damage mechanisms: cyclic load, horizontal load, scour and corrosion, establishes the damage change rate function of each mechanism, couples each damage component through differential equations, and adds inter-mechanism coupling terms to construct a support stiffness damage dynamics model. The real-time bearing capacity dynamic correction module is used to solve the total damage factor at the current moment based on the support stiffness damage dynamics model, correct the updated comprehensive support stiffness, obtain the real-time comprehensive support stiffness, and use the real-time comprehensive support stiffness to update the initial vertical ultimate bearing capacity to obtain the real-time vertical ultimate bearing capacity.

[0043] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0044] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution.

[0045] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0046] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for determining the ultimate vertical bearing capacity of wharf foundation piles, characterized in that, The specific steps include: S1: Obtain the test data of static cone penetration test at the design location of the foundation pile and the key mechanical parameters of each soil layer. Based on the initial test data of static cone penetration test and the key mechanical parameters of each soil layer, determine the initial comprehensive support stiffness and initial vertical ultimate bearing capacity of the foundation pile. S2: When a random event occurs, the impact type of the random event is classified and the characteristic data of the random extreme event is obtained. Based on the characteristic data of the random extreme event, an event intensity index is constructed. The damage sensitivity coefficient is calibrated by finite element method. The initial comprehensive support stiffness is updated based on the event intensity index and the damage sensitivity coefficient. S3: Obtain historical service data of the foundation piles up to the time of the random event, introduce four damage mechanisms: cyclic load, horizontal load, scour and corrosion, establish damage change rate function for each mechanism, couple each damage component through differential equations, and add inter-mechanism coupling terms to construct a support stiffness damage dynamic model. S4: Based on the support stiffness damage dynamics model, solve the total damage factor at the current moment, correct the updated comprehensive support stiffness, obtain the real-time comprehensive support stiffness, update the initial vertical ultimate bearing capacity using the real-time comprehensive support stiffness, and obtain the real-time vertical ultimate bearing capacity.

2. The method for determining the vertical ultimate bearing capacity of wharf foundation piles according to claim 1, characterized in that: The initial test data of the pore pressure static cone penetration test includes continuous data on cone tip resistance, sidewall friction, and pore water pressure variations with depth; and the total overburden stress and effective overburden stress are calculated at each test depth, where the total overburden stress is the total weight of the soil column above the test depth, and the effective overburden stress is the difference between the total overburden stress and the pore water pressure at the test depth; the cone tip resistance and sidewall friction are corrected for probe cross-section inequivalence and pore water pressure effects to obtain the corrected cone tip resistance and corrected sidewall friction; normalization is performed to obtain the normalized cone tip resistance and friction ratio; the total overburden stress is subtracted from the corrected cone tip resistance to obtain the difference, and then the difference is divided by the effective overburden stress to obtain the normalized cone tip resistance; Subtract the total overburden stress from the corrected cone tip resistance to obtain the difference. Then divide the corrected sidewall friction resistance by this difference and multiply the result by 100% to obtain the normalized friction ratio, expressed as a percentage.

3. The method for determining the vertical ultimate bearing capacity of wharf foundation piles according to claim 2, characterized in that: Based on the normalized cone tip resistance and normalized friction ratio, multiple soil layers are divided at the design location of the foundation pile in the soil behavior type chart, and the key mechanical parameters of each soil layer are obtained, including: soil type, initial small strain shear modulus and reference shear strain of each soil layer. Different inversion formulas are used to obtain the initial small strain shear modulus of each soil layer for different soil types; among them, for sandy soil layers, the initial small strain shear modulus of sandy soil layers is obtained by combining the modified cone tip resistance with the empirical coefficient of sandy soil layers. For clay soil layers, the undrained shear strength of the soil layer is derived from the initial test data of pore pressure static cone penetration test. The initial small strain shear modulus of the clay soil layer is obtained based on the undrained shear strength and the empirical coefficient of the clay soil layer. The reference shear strain is determined for each soil layer according to the soil classification through indoor bending element and resonant column tests.

4. The method for determining the vertical ultimate bearing capacity of wharf foundation piles according to claim 3, characterized in that: The pile body is discretized into several units. The bearing stiffness of the soil layer in each unit is characterized by the initial tangential stiffness of the nonlinear spring model through the initial small strain shear modulus and reference shear strain value of each soil layer. The bearing stiffness of all units along the entire pile length is integrated and synthesized to obtain the initial comprehensive bearing stiffness of the pile. Based on the initial test data of pore pressure static penetration, the ultimate resistance at the pile tip and the total ultimate frictional resistance on the pile side are calculated respectively. The sum of the two is the initial vertical ultimate bearing capacity.

5. The method for determining the vertical ultimate bearing capacity of wharf foundation piles according to claim 1, characterized in that: When a random event occurs, the characteristic data of the random extreme event include: impact type, peak load, peak acceleration, duration, and effective parameter mass of the foundation pile; among them, the impact type of the random event is classified into: vibration event and impact event; an update function based on the characteristic data of the extreme event is established, the comprehensive support stiffness update coefficient is designed, and the initial comprehensive support stiffness is updated.

6. The method for determining the vertical ultimate bearing capacity of wharf foundation piles according to claim 5, characterized in that: The impact types include impact events and vibration events, and reference intensity indices are set for different impact types. For impact events, the event intensity index is determined by the peak load and duration in the extreme event characteristic data. Specifically, the event intensity index value of the impact event is the product of the peak load and duration divided by the product of the effective parameter mass of the foundation pile and the gravitational acceleration. For vibration events, the event intensity index of the vibration event is obtained by integrating the peak acceleration in the extreme event characteristic data, and the event intensity index value of the vibration event is obtained based on the reference intensity index corresponding to the vibration event, specifically the integral of the peak acceleration over the duration.

7. The method for determining the vertical ultimate bearing capacity of wharf foundation piles according to claim 6, characterized in that: The initial comprehensive support stiffness is updated based on random extreme event characteristic data. Specifically, the damage sensitivity coefficient of the comprehensive support stiffness is calibrated through finite element numerical simulation. The comprehensive support stiffness update coefficient is determined by combining the obtained event strength index value, the corresponding reference strength index, and the damage sensitivity coefficient of the support stiffness. Specifically, the event strength index value is divided by the reference strength index to obtain a ratio, this ratio is multiplied by the damage sensitivity coefficient, and the negative of the result of this step is taken. A natural constant is constructed using the above results as an exponent. The updated comprehensive support stiffness coefficient is obtained by multiplying the updated comprehensive support stiffness by the initial comprehensive support stiffness using the exponential function value with base 0.

8. The method for determining the vertical ultimate bearing capacity of wharf foundation piles according to claim 7, characterized in that: Historical service data of the foundation piles up to the time of the random event were obtained, and four damage mechanisms—cyclic load, horizontal load, scour, and corrosion—were introduced. Specifically, damage change rate functions for each mechanism were established, and data on cyclic load damage components, horizontal load damage components, scour damage components, and corrosion damage components were obtained. The cyclic load damage component was constructed by introducing historical data on the number of cycles and corresponding stress ratios of the soil in which each discrete unit of the pile body was located up to the time of the random extreme event, and constructing equivalent cycle number and equivalent cyclic stress ratio. Based on the equivalent cycle number and equivalent cyclic stress ratio, a power function-form dynamic equation was used to construct the cyclic load damage change rate function to obtain the cyclic load damage component. The horizontal load damage component is obtained by acquiring the maximum bending moment of the pile and the proportion of the pile-soil void area up to the occurrence of the random extreme event, setting the pile yield bending moment and horizontal load damage parameters, constructing the horizontal load damage change rate function, and obtaining the horizontal load damage component. By introducing the distribution function of the time-varying scour depth and pile diameter along the depth up to the occurrence of the random extreme event, and setting the inherent geometric parameter of the total side surface area of ​​the pile, a scour damage change rate function is constructed based on the above parameters to obtain the scour damage components. The corrosion damage is obtained by acquiring the time-varying corrosion rate up to the current moment, the corrosion initiation time, and the distribution function of the initial diameter of the pile along the depth, and by setting the inherent geometric parameter of the initial total cross-sectional area of ​​the pile, constructing the corrosion damage change rate function, and obtaining the corrosion damage components.

9. The method for determining the vertical ultimate bearing capacity of wharf foundation piles according to claim 7, characterized in that: Based on the support stiffness damage dynamics model, the total damage factor at the current moment is solved, and the updated comprehensive support stiffness is corrected. Specifically, the total damage factor at the current moment is obtained by numerical integration of the support stiffness damage dynamics model based on the above-mentioned multi-mechanism damage coupling when random extreme events occur. The difference between 1 and the total damage factor is multiplied by the updated comprehensive support stiffness to obtain the real-time comprehensive support stiffness. Based on the ratio of the real-time comprehensive support stiffness to the initial comprehensive support stiffness, a correction coefficient is set that combines the nonlinear relationship between the comprehensive support stiffness and the vertical ultimate bearing capacity. The real-time vertical ultimate bearing capacity is determined by multiplying the ratio of the real-time comprehensive support stiffness to the initial comprehensive support stiffness by the initial vertical ultimate bearing capacity and then by the correction coefficient.

10. A system for determining the vertical ultimate bearing capacity of wharf foundation piles, characterized in that, The system for determining the vertical ultimate bearing capacity of wharf foundation piles is used to execute the method for determining the vertical ultimate bearing capacity of wharf foundation piles as described in any one of claims 1-9, including: The initial parameter accurate inversion module is used to obtain the test data of pore pressure static cone penetration test at the design location of the foundation pile and the key mechanical parameters of each soil layer. Based on the initial test data of pore pressure static cone penetration test and the key mechanical parameters of each soil layer, the initial comprehensive support stiffness and initial vertical ultimate bearing capacity of the foundation pile are determined. The extreme event impact response update module is used to classify the impact type of random events and obtain random extreme event characteristic data when random events occur. Based on the random extreme event characteristic data, an event intensity index is constructed, the damage sensitivity coefficient is calibrated through finite element method, and the initial comprehensive support stiffness is updated based on the event intensity index and the damage sensitivity coefficient. The multi-mechanism damage dynamics construction module is used to obtain the service history data of the foundation pile up to the time of the random event. It introduces four damage mechanisms: cyclic load, horizontal load, scour and corrosion, establishes the damage change rate function of each mechanism, couples each damage component through differential equations, and adds inter-mechanism coupling terms to construct a support stiffness damage dynamics model. The real-time bearing capacity dynamic correction module is used to solve the total damage factor at the current moment based on the support stiffness damage dynamics model, correct the updated comprehensive support stiffness, obtain the real-time comprehensive support stiffness, and use the real-time comprehensive support stiffness to update the initial vertical ultimate bearing capacity to obtain the real-time vertical ultimate bearing capacity.

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