Offshore pile-insertion area foundation repair method and system based on soil gradation optimization

Abstract

The present invention discloses a method and system for repairing the foundation of an offshore pile-pulling area based on soil gradation optimization, which relates to the field of foundation repair technology, including: collecting disturbed soil and original soil samples in the offshore pile-pulling construction area, establishing a soil combination model in the disturbed area, and configuring the soil in the disturbed area; obtaining the total bearing capacity requirement of the mobile platform and the depth of the pile shoe into the mud, and calculating the bearing capacity requirement of the pile-pulling area; taking the bearing capacity requirement of the pile-pulling area as the optimization target, configuring a bearing capacity evaluation function, performing an optimization analysis of the filler gradation, and establishing the optimization analysis result; controlling the filler ratio and the particle mixing method according to the optimization analysis result, and completing the foundation repair of the offshore pile-pulling area through layered backfilling and vibration compaction technology. The present invention solves the technical problem in the prior art that the strength of the disturbed soil in the well site is reduced due to repeated construction of the pile-pulling area, resulting in safety hazards such as slipping piles on the platform, and achieves the technical effect of improving the mechanical properties of the foundation in the disturbed area and ensuring the safe and stable operation of the platform.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation repair, and in particular to a method and system for repairing offshore pile-insertion areas based on soil gradation optimization. Background Art

[0002] In offshore oil and gas development, wind power installation and other projects, self-elevating platforms or mobile platforms need to achieve operational positioning and stabilization by inserting and removing piles. The platform repeatedly inserts and removes piles in the same well site area, which easily forms a large number of pile pits on the seabed. These pile pits are mostly formed by the collapse of the pit wall soil and the backfilling of surrounding sediments. The backfill material composition is loose, the structure is disordered, and it is highly disturbed. There are significant differences in particle grading, physical properties and mechanical strength from the original seabed soil. The foundation soil in the disturbed area usually exhibits problems such as low bearing capacity, poor shear resistance, and large settlement deformation, which cannot meet the mechanical stability requirements of subsequent pile insertion operations. The heterogeneity of the foundation soil structure and the degradation of mechanical properties can easily lead to puncture, slippage, and even overturning of the platform pile shoe, posing a serious safety hazard.

[0003] At present, most of the repair technologies for disturbed well site foundations use a single reinforcement material or grouting method, without quantitative optimization and control based on the actual particle grading and mechanical properties of the disturbed area, resulting in limited foundation repair effects. Summary of the Invention

[0004] The present application provides a method and system for offshore pile-insertion area foundation repair based on soil grading optimization, which is used to solve the technical problem in the prior art that the strength of the disturbed soil in the well site is reduced due to repeated construction of pile insertion and extraction, resulting in safety hazards such as slipping piles on the platform.

[0005] In view of the above problems, the present application provides a method and system for offshore pile insertion and extraction area foundation repair based on soil gradation optimization.

[0006] In a first aspect of the present application, a method for repairing offshore pile-insertion areas based on soil gradation optimization is provided, the method comprising:

[0007] After analyzing historical drilling data, additional samples of disturbed soil and undisturbed soil in the offshore pile insertion and extraction construction area are collected. Based on the analysis of the sampled samples, a soil combination pattern of the disturbed area is established to configure the soil in the disturbed area. The total bearing capacity requirement of the mobile platform and the depth of the pile shoe in the mud are obtained, and the pile bearing capacity requirement is calculated using the total bearing capacity requirement and the depth of the pile shoe in the mud. With the pile bearing capacity requirement as the optimization target, after configuring the bearing capacity evaluation function based on the soil in the disturbed area, an optimization analysis of the filler gradation is performed to establish the optimization analysis results. After controlling the filler ratio and particle mixing method according to the optimization analysis results, the foundation repair of the offshore pile insertion and extraction area is completed through layered backfilling and vibration compaction technology.

[0008] The second aspect of the present application provides an offshore pile insertion and extraction area foundation repair system based on soil gradation optimization, the system comprising:

[0009] The soil combination model establishment module is used to analyze historical drilling data and then collect additional disturbed soil and original soil samples in the offshore pile insertion and extraction construction area, establish a soil combination model for the disturbed area based on the sampling sample analysis, and configure the soil in the disturbed area; the pile bearing capacity requirement calculation module is used to obtain the total bearing capacity requirement of the mobile platform and the pile shoe penetration depth, and use the total bearing capacity requirement and the pile shoe penetration depth to calculate the pile bearing capacity requirement; the optimization analysis module is used to use the pile bearing capacity requirement as the optimization target, configure the bearing capacity evaluation function based on the soil in the disturbed area, perform an optimization analysis of the filler gradation, and establish the optimization analysis result; the foundation repair module is used to control the filler ratio and particle mixing method according to the optimization analysis result, and complete the foundation repair of the offshore pile insertion and extraction area through layered backfilling and vibration compaction process.

[0010] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0011] After analyzing historical drilling data, this application collects additional samples of disturbed soil and original soil in the offshore pile insertion and extraction construction area, establishes a soil combination pattern in the disturbed area based on the sample analysis, and configures the soil in the disturbed area; obtains the total bearing capacity requirement of the mobile platform and the depth of the pile shoe into the mud, and uses the total bearing capacity requirement and the pile shoe into the mud to calculate the pile insertion bearing capacity requirement; takes the pile insertion bearing capacity requirement as the optimization target, configures the bearing capacity evaluation function based on the soil in the disturbed area, performs an optimization analysis of the filler gradation, and establishes the optimization analysis result; controls the filler ratio and particle mixing method based on the optimization analysis result, and completes the foundation repair of the offshore pile insertion and extraction area through layered backfilling and vibration compaction process. The present invention solves the technical problem in the prior art that the strength of the disturbed soil in the well site is reduced due to repeated construction of pile insertion and extraction, resulting in safety hazards such as pile sliding on the platform. By analyzing the combination pattern of disturbed soil and original soil, optimizing the soil gradation based on the bearing capacity requirement, and combining the layered backfilling and vibration compaction process, the mechanical properties of the foundation in the disturbed area are improved, and the safe and stable operation of the platform is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0013] Figure 1A schematic flow chart of a method for repairing offshore pile-insertion areas based on soil gradation optimization provided in an embodiment of the present application;

[0014] Figure 2 Schematic diagram of the structure of the offshore pile-plugging area foundation repair system based on soil gradation optimization provided in an embodiment of the present application.

[0015] Description of the accompanying drawings: soil combination model establishing module 11, pile bearing capacity demand calculation module 12, optimization analysis module 13, foundation repair module 14. DETAILED DESCRIPTION

[0016] This application provides a foundation repair method and system for offshore pile insertion and extraction areas based on soil gradation optimization, aiming to solve the technical problem in the prior art that the strength of the disturbed soil in the well site is reduced due to repeated construction of pile insertion and extraction, resulting in safety hazards such as pile sliding on the platform. By analyzing the combination pattern of disturbed soil and original soil, optimizing soil gradation based on bearing capacity requirements, and combining layered backfilling and vibration compaction technology, the technical effect of improving the mechanical properties of the foundation in the disturbed area and ensuring the safe and stable operation of the platform is achieved.

[0017] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only some of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0018] It should be noted that any variations of the terms "include" and "have" are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or modules that are not clearly listed or are inherent to these processes, methods, products or devices.

[0019] Example 1, as Figure 1 As shown, the present application provides a method for repairing offshore pile-insertion areas based on soil gradation optimization, the method comprising:

[0020] Step S100: After analyzing historical drilling data, additional disturbed soil and undisturbed soil samples are collected from the offshore pile insertion and extraction construction area. Based on the sample analysis, a soil combination model of the disturbed area is established to configure the soil in the disturbed area.

[0021] In the embodiments of the present application, a soil combination model of the disturbed area is constructed by integrating historical data and on-site investigations. First, historical drilling data of the offshore pile insertion and extraction construction area are obtained, including geological histograms and related geotechnical test data, to grasp the basic structure and mechanical properties of the original strata in the area. Subsequently, a supplementary on-site investigation is carried out to collect samples of disturbed soil and undisturbed soil respectively to provide a measured basis for comparative analysis. By performing particle grading analysis on the samples, the distribution patterns of particles of different particle sizes are clarified, and combined with microstructural observations, the pore structure changes and aggregate destruction in the disturbed soil are identified. At the same time, the physical components and mechanical properties of the disturbed area are divided into zones according to the analysis results, reflecting the differences in material composition and mechanical properties of different regions. Finally, the particle grading, microstructural characteristics and mechanical zoning information are integrated to establish a soil combination model that can characterize the characteristics and spatial distribution patterns of the disturbed soil.

[0022] Finally, the composition ratio and mixing method of the filler particles are guided by the soil combination pattern to complete the configuration of the soil in the disturbed area.

[0023] Furthermore, in the method provided in the embodiment of the application, after analyzing the historical drilling data, additional samples of disturbed soil and undisturbed soil in the offshore pile insertion and extraction construction area are collected, and a soil combination model of the disturbed area is established based on the analysis of the sampled samples, which also includes:

[0024] Obtain geological histograms and geotechnical test data from historical drilling data, and collect disturbed soil and undisturbed soil samples through supplementary on-site survey data; divide the physical components and mechanical property zones of the disturbed area through soil particle analysis and microstructure observation; establish particle grading based on soil particle analysis, and use particle grading, microstructure observation results, physical components and mechanical property zones to establish a soil combination model for the disturbed area.

[0025] In the embodiment of the present application, historical drilling data is first obtained from the historical database, and geological histograms and previous geotechnical test data are extracted, including stratum distribution, soil layer thickness, sediment type, standard penetration value (SPT), and basic mechanical parameters such as density, moisture content, porosity, and shear strength. These data provide a basis for the structural stability of the original stratum and the regional sedimentary background. At the same time, since offshore pile insertion and extraction operations will cause structural damage and strength attenuation of the soil in the local disturbance area, and there are complex components such as collapsed backfill and seabed scouring sediments in the pile pit, historical data are not sufficient to reflect the actual disturbance situation. Therefore, additional on-site drilling and sampling are carried out to collect disturbed soil samples in the pile pit and original soil samples outside the pile pit for comparative analysis of the disturbance effect and support subsequent repair modeling. After completing this step, a control sample system of disturbed and original soil is established.

[0026] After sample collection, particle grading analysis and microstructural observations are conducted based on laboratory testing to further reveal the material composition and structural state of the disturbed area. Particle grading analysis uses methods such as dry screening, water sedimentation, or laser particle size analysis to determine the mass percentage of particles of different sizes in the sample, and to draw a particle grading curve to obtain key parameters such as the median particle size, uniformity coefficient, and non-uniformity coefficient. This allows evaluation of whether the soil is continuously graded, well-graded, or discontinuously graded, thereby identifying the changing characteristics of the particle composition in the disturbed area. At the same time, microstructural observations are conducted using a scanning electron microscope (SEM) to analyze the integrity of the soil aggregate structure, porosity changes, microcrack distribution, and cementation characteristics, so as to determine the degree of disturbance and structural degradation at a microscopic scale. Based on the comprehensive particle grading and microstructure data, the disturbed area is divided into several physical component zones (such as areas dominated by sand, silt, and clay) and mechanical property zones (such as low shear strength zones, high compression zones, etc.), to clarify the differences and spatial distribution patterns in the physical composition and engineering properties of different areas, thereby completing the zoning and identification of the physical and mechanical properties of the disturbed area.

[0027] After obtaining the multi-scale properties of the soil, the particle grading curve, microstructural observations, and physical and mechanical zoning information are further integrated to construct a complete soil composition model for the disturbed area. The particle grading curve provides a quantitative expression of the particle size distribution of the disturbed soil, which can serve as a basis for evaluating the composition of the target soil for restoration. The microstructure reveals the impact of disturbance on the internal structural continuity and mechanical stability of the soil, providing mesoscopic support for understanding the strength degradation mechanism. The physical components and mechanical zoning establish a spatial variation model of the disturbed soil. By integrating these three, through atlas mapping, zoning identification, and combined modeling, a multi-dimensional, quantifiable soil composition model is ultimately established that reflects the particle composition, structural state, and mechanical behavior characteristics of the disturbed soil.

[0028] Step S200: obtaining the total bearing capacity requirement of the mobile platform and the depth of the pile shoe inserted into the mud, and calculating the pile bearing capacity requirement using the total bearing capacity requirement and the depth of the pile shoe inserted into the mud.

[0029] In the embodiment of this application, the total bearing capacity requirement of the mobile platform is first obtained. This value is provided by the design unit. The bearing capacity requirement of each pile is the total bearing capacity requirement minus the number of piles. Next, the depth of the pile shoe into the mud is obtained, that is, the depth of the platform pile shoe into the disturbed soil of the seabed when the pile is inserted, which is recorded as , in meters, this parameter is derived based on historical construction data or measured pile shoe penetration depth.

[0030] After obtaining the total bearing capacity requirement of the mobile platform and the depth of the pile shoe into the mud, Calculate, where It is the bearing capacity requirement of the piles, that is, the minimum ultimate bearing capacity that the foundation soil in the disturbed area must provide. is the estimated value of the resistance per unit area of ​​the pile end in disturbed soil, Calculated, The undrained shear strength of the disturbed soil at the pile tip depth, in kPa. This value is obtained by triaxial UU testing after field drilling sampling. It is the dimensionless end resistance bearing capacity coefficient under disturbance state, set by technical experts. is the maximum average contact area of ​​the pile shoe bottom (m²), which is directly extracted from the pile shoe structure design drawing. It is the bearing efficiency correction factor of the disturbed soil pile side (dimensionless), which is used to characterize the actual bearing capacity contributed by the side wall area of ​​the disturbed soil during the pile insertion process and is set by technical experts. is the geometric volume of the pile shoe (m³), which is used to estimate the additional bearing capacity provided by the soil in the pile shoe side resistance area. Calculated.

[0031] By using the above formula, we can calculate As the pile bearing capacity requirement.

[0032] Step S300: Taking the bearing capacity requirement of the pile as the optimization target, after configuring the bearing capacity evaluation function based on the soil in the disturbance zone, performing an optimization analysis of the filler gradation, and establishing an optimization analysis result.

[0033] In this application's example, a bearing capacity evaluation function that comprehensively reflects foundation performance is constructed, taking the required pile bearing capacity as the optimization objective. This function, based on core indicators such as ultimate bearing capacity, shear strength, compression modulus, and void ratio, introduces repair adjustment factors such as disturbance intensity, particle gradation, and microstructure. These factors are combined and weighted using weight coefficients to form a multi-dimensional, multi-constrained foundation mechanical performance evaluation model. Within this function system, an optimization analysis is performed for the optional filler type and gradation combinations. The suitability of each combination is evaluated by combining mechanical experimental data with numerical simulation results, ultimately outputting the optimization analysis results.

[0034] Furthermore, in the method provided in the embodiment of the application, configuring a bearing capacity evaluation function based on the soil in the disturbance zone further includes:

[0035] establishing a disturbance zone correction term using the disturbance zone soil;

[0036] The carrying capacity evaluation function is configured according to the disturbance zone correction term as follows:

[0037] ;in, Characterize the bearing capacity evaluation function, The ultimate bearing capacity of the repaired soil. is the minimum value of the pile bearing capacity requirement, Characterize the shear strength of the repaired soil, Characterizes the minimum anti-slip requirement, is the compression modulus of the repaired soil, Characterizes the minimum value of settlement control requirements, Characterize the critical void ratio, determined based on triaxial tests, is the porosity ratio of the repaired soil, is the index of the disturbance zone correction term, Characterizing the disturbance zone correction term The weight factor of the item, Characterization The correction term of the term, where is the disturbance intensity correction term, is the particle gradation distortion correction term, is the microstructure degradation correction term, are the weight factors of bearing capacity, shear strength, compression modulus and porosity penalty terms respectively.

[0038] In the present embodiment, the disturbance zone correction term is first established using the disturbed soil to identify the influence of the disturbance effect on the filler performance and overall bearing capacity. Through the physical and structural analysis of the disturbed soil samples, the three main types of mechanical degradation characteristics caused by the disturbance are summarized, and the disturbance intensity correction terms are constructed respectively. , particle gradation distortion correction term and microstructural degradation correction , and based on this, it is used as the basis for characterizing the disturbance response parameters, and then embedded into the subsequent load-bearing performance evaluation function to achieve a comprehensive measurement of the adaptability of different filler combinations. Characterizes the decrease ratio of undrained shear strength in the disturbed area, usually obtained by comparing the CPT cone resistance between the disturbed area and the original area; Reflects the degree of deviation of particle distribution between the current filler gradation and the ideal gradation, and is obtained based on the cumulative deviation integral of the two particle size distribution curves; It is used to characterize the degree of microstructural damage and quantitatively evaluates parameters such as the aggregate breakage rate and porosity distribution in SEM images before and after the disturbance. After numerical processing, these disturbance terms can be normalized to dimensionless coefficients between 0 and 1, indicating the degree of degradation caused by the disturbance.

[0039] On this basis, the bearing capacity evaluation function is configured according to the disturbance zone correction term, and the following function is constructed to systematically quantify the score of each filler grading scheme: ;in, Characterize the bearing capacity evaluation function, The ultimate bearing capacity of the repaired soil. is the minimum value of the pile bearing capacity requirement, Characterize the shear strength of the repaired soil, obtained by triaxial CU test or direct shear test, Characterize the minimum anti-slip requirement, according to the structural stability design standard, is the compression modulus of the repaired soil, which is obtained by regression of the slope of the stress-strain curve of the triaxial shear test or the consolidation test. Characterizes the minimum value of settlement control requirements, Characterize the critical void ratio, determined based on triaxial tests, The porosity ratio of the repaired soil is obtained by converting the dry density to the particle density and by measuring the mass volume after sampling. is the index of the disturbance zone correction term, Characterizing the disturbance zone correction term The weight factor of each item is pre-set by technical experts. Characterization The correction term of the term, where is the disturbance intensity correction term, is the particle gradation distortion correction term, is the microstructure degradation correction term, They are the weight factors of bearing capacity, shear strength, compression modulus, and porosity penalty terms, which are pre-set by technical experts.

[0040] Furthermore, in the method provided in the embodiment of the application, the ultimate bearing capacity of the repaired soil is calculated by the following formula:

[0041] in, The undrained shear strength of the pile end after repair. , To measure the undrained shear strength of the repaired soil, is the dimensionless bearing capacity coefficient, is the maximum average contact area of ​​the pile shoe, is the drainage efficiency correction term of the soil beside the pile after repair, is the volume of the pile shoe.

[0042] In the embodiment of the present application, the ultimate bearing capacity of the repaired soil is Calculate, where Characterizes the ultimate bearing capacity of the soil after repair, the unit is kN, and is used to describe the maximum bearing force that the pile shoe can obtain after being inserted into the foundation soil in the repair area. The undrained shear strength of the pile end after repair. , It is the undrained shear strength of the repaired soil, in kPa, which can be obtained by inversion of the indoor triaxial undrained shear test (UU) or the cone penetration test (CPT), reflecting the ability of the filler to resist shear failure under in-situ conditions. is a dimensionless bearing capacity coefficient, typically ranging from 9 to 12, set by technical experts. A is the maximum average contact area of ​​the pile shoe, expressed in m². This value is determined by the geometry of the pile shoe bottom and is derived from platform structural drawings or CAD modeling. This is a correction term for the drainage efficiency of the soil beside the pile after repair. It is used to correct the effective bearing capacity of the contact area between the disturbed filler and the pile shoe sidewall. This coefficient takes into account drainage conditions, compaction quality, and the degree of structural disturbance. It is calibrated through field experience or inferred through CPT side resistance tests, and its typical value is 0.6 to 1.0. is the volume of the pile shoe, which is determined by the pile shoe bottom area A and the depth of penetration into the mud. Obtained by multiplication.

[0043] The ultimate bearing capacity of the repaired soil is calculated by the above formula , the calculated ultimate bearing capacity It needs to be greater than the bearing capacity requirement of each pile.

[0044] Furthermore, in the method provided in the embodiment of the application, the optimization analysis of filler gradation further includes:

[0045] Establish a stage evaluation for optimization and configure dynamic key parameter weights mapped to the stages. The dynamic key parameters include sensitivity parameters, porosity difference parameters, and non-uniformity coefficient parameters. After constructing the initial population, use the key parameter weights of the initial stage to perform a search update based on the dynamic key parameters, and perform search iterations of the initial population based on the search update results to complete the optimization analysis.

[0046] In the embodiment of the present application, first, based on the phased goal of performance improvement during the repair of the disturbance zone, a stage evaluation of optimization is established, and the entire filler combination optimization process is divided into three functional stages, namely the initial exploration stage, the mid-term convergence stage and the final fine-tuning stage, which respectively correspond to the coarse screening, directional convergence and structural regulation process of the filler combination space. In each stage, according to the transfer of optimization focus, the dynamic key parameter weights mapped with the stage are configured to guide the optimization algorithm to dynamically focus on the indicator dimension with the most control value at present. The dynamic key parameters introduced include sensitivity parameters, porosity difference parameters and non-uniformity coefficient parameters, and their corresponding weight coefficients are respectively The sensitivity parameter is used to reflect the degree of influence of different particle size components on the output results of the bearing capacity evaluation function. The Sobol global sensitivity analysis method is usually used to quantify the disturbance effect of the input variables and extract the sensitivity ranking results between the particle size components and the output performance. The weight corresponding to the sensitivity parameter is , which mainly dominates the initial exploration stage; the porosity difference parameter is expressed in the form Characterization, where is the critical porosity of the soil in the disturbed area, which is extracted from the dilatation-contraction turning point identified in the triaxial shear test. n is the actual porosity of the current filler combination, which is calculated by converting the dry density and the particle specific gravity. It reflects the density of the filler under the compaction process and the degree of proximity to the structural boundary. The weight corresponding to this parameter is It mainly dominates the mid-term convergence stage; the unevenness coefficient parameter adopts the particle size unevenness coefficient ,in and They represent the particle sizes corresponding to the cumulative passing percentages of 60% and 10%, respectively. The data are obtained through sieving tests and are used to describe the extent of particle distribution and evaluate the compactibility and structural coordination of the filler. The weight corresponding to this parameter is , which mainly dominates the final fine-tuning stage. The weights of the above three parameters Dynamic allocation is carried out according to the stage goals to build a multi-stage search leading mechanism, so that the optimization search can automatically focus on the most critical regulation direction at different stages.

[0047] After completing the stage division and parameter system configuration, the initial population is constructed, that is, multiple particle size ratio combinations are randomly generated in the filler design variable space. Each combination is defined as a particle. The particle properties include the proportions of coarse sand, medium sand, fine sand, silt and other components, which constitute the starting point of the optimization search. Afterwards, the key parameter weights of the initial stage are used to perform search updates based on dynamic key parameters. Specifically, the fitness of each particle in the initial population is first calculated through the bearing capacity evaluation function. After the fitness calculation is completed, the particle similarity analysis is performed on the particle group, and the K-means clustering algorithm is used to divide the particles into multiple similar subgroups according to the similarity of the particle size ratio vector or the mechanical index vector. According to the fitness score and similar clustering results, the particle subgroups with better performance are extracted, and the same-direction search constraint is constructed, that is, the population is guided to the current local optimal direction for structural aggregation; at the same time, the current global optimal particle is identified, and a variation search constraint is established with it as the center. The Gaussian perturbation function is introduced to perform particle size perturbation operations to maintain search diversity and avoid falling into local optimal solutions; on this basis, combined with the stage key parameter weights (that is, the initial Dominant, mid-term Dominant, late dominant), dynamically weight the update amplitude of each variable, construct update search constraints, and realize parameter-guided search trajectory adjustment.

[0048] Ultimately, under the combined influence of the same-direction search constraints, mutation search constraints, and update search constraints, the particle swarm completes its search update and enters the next generation of particle swarm fitness evaluation and search iterations. Through this mechanism, the swarm maintains a balance between global search and local focus, gradually approaching the optimal performance solution over multiple stages. When the bearing capacity evaluation function converges or reaches the maximum number of iterations, the optimal filler gradation combination is output, along with its corresponding ultimate bearing capacity, porosity, modulus, and disturbance response evaluation values, providing a performance-matched filler design solution for foundation repair in disturbed areas.

[0049] Furthermore, in the method provided in the embodiment of the application, the search update based on the dynamic key parameters using the key parameter weights in the initial stage further includes:

[0050] The fitness of each particle in the initial population is calculated using the carrying capacity evaluation function to generate a fitness calculation result; a particle similarity analysis is performed on each particle in the initial population to generate a similarity cluster; a same-direction search constraint is obtained based on the fitness calculation result and the similarity cluster; a particle with a maximum fitness value in the fitness calculation result is obtained, and a mutation search constraint is established based on the particle with the maximum fitness value; an update search constraint is established based on the key parameter weights of the initial stage and the dynamic key parameters; and a search update is completed based on the same-direction search constraint, the mutation search constraint, and the update search constraint.

[0051] In the present embodiment, the fitness of each particle in the initial population is first calculated using the bearing capacity evaluation function method. Each particle represents a specific filler gradation combination, and its fitness is calculated by the function, and the fitness calculation result is generated by calculation.

[0052] Secondly, the K-means clustering method is used to perform particle similarity analysis on each particle in the population. This method is based on the filler ratio vector of the particle (such as coarse sand, medium sand, fine sand, silt, etc.) and the calculated performance index vector (such as ) as clustering features, and after normalization, the K-means algorithm is used to divide the particles into several cluster centers to obtain similar clusters.

[0053] After obtaining the cluster structure, the cluster centroid-guided method is used to establish a same-direction search constraint. Specifically, the particle with the highest fitness in each cluster is selected as the "local optimal center." The vector direction between the other particles in the cluster and the center is then calculated to construct a relative motion path. A step-size constraint is then set to ensure that these particles preferentially approach this direction in the next round of search. This process ensures that particles converge along the known dominant solution direction, thereby improving local convergence speed.

[0054] Next, we use the Gaussian perturbation mutation method to construct mutation search constraints. This method identifies the particle with the highest fitness value in the current population and defines it as the "global optimal particle." We then introduce a Gaussian perturbation on the particle's size ratio vector to generate a number of mutated particles. In practice, the perturbation amplitude is adaptively adjusted based on the particle's historical variation. The perturbed particles are then added to the current population or replace some low-fitness particles. This approach guides the search beyond local optima, enhancing global exploration capabilities and is widely used in optimizing complex multimodal objective functions.

[0055] Then, the adaptive weighted update method is used to construct the updated search constraints based on the dynamic parameter weights set in the initial stage of optimization. contribution of ), porosity difference parameter (i.e. ), the non-uniformity coefficient parameter (i.e. Assign weights separately , dynamically adjust the control focus at different stages. Specifically, in the initial stage, , mid-term strengthening , terminal protrusion , so that particles focus on responding to the main control indicators of the current stage during the update process. For example, when When the weight is increased, the particle size ratio that has a greater impact on the porosity ratio (such as silt) obtains a larger step update probability in the search, which allows it to approach the optimal dense state more quickly.

[0056] Finally, the three types of constraint information are integrated and the constrained superposition iteration method is used to complete a particle search update. In this step, the next generation position of the particle is formed by superimposing the same-direction search vector, the mutation perturbation vector and the weighted update vector. At the same time, the updated particle size ratio is normalized to ensure that the sum of the ratios is 1 to avoid exceeding the physical boundary. The updated particle group is sent to the next round of fitness calculation and search iteration process, which is carried out round by round until the evaluation function is satisfied. When convergence or the maximum number of iterations is reached, the optimal filler gradation combination is finally output.

[0057] Step S400: After controlling the filler ratio and particle mixing method according to the optimization analysis results, the foundation repair of the offshore pile insertion and extraction area is completed through layered backfilling and vibration compaction processes.

[0058] In the embodiment of the present application, after the filler gradation optimization analysis is completed, the optimal filler ratio and particle mixing method are extracted based on the output optimization analysis results, that is, the optimal filler gradation combination, to carry out the actual repair work of the disturbed area foundation. This process ensures that the filler forms a structurally stable and load-bearing consolidated body with good bearing performance in different disturbance characteristic areas by combining layered backfilling with vibration compaction. First, based on the properties of the soil in the disturbed area, static penetration or geological profile data is used to identify the area, and clearly divide the high sensitivity area and high porosity area to provide a basis for differentiated construction control. Subsequently, referring to the particle ratio and mechanical parameters determined in the optimization analysis, a unified standard thickness layering scheme is first established, and then combined with regional differences, local fine-tuning of the thickness and particle size structure is performed to generate a more targeted adaptive layering result. Finally, layered backfilling is carried out at the construction site according to the adaptive layering scheme. After each layer is completed, a high-frequency flat vibrator or impact rolling equipment is used for vibration compaction treatment to improve the filler density, reduce porosity and enhance interlayer bonding. Through this integrated process, customized repair of the disturbed area under different structural conditions is achieved, effectively ensuring the overall strength, stability and bearing reliability of the foundation in the offshore pile insertion and extraction area.

[0059] Furthermore, in the method provided in the embodiment of the application, the foundation repair of the offshore pile insertion and extraction area is completed by the layered backfilling and vibration compaction process, and further includes:

[0060] Based on the soil in the disturbed area, regional identification is performed to establish a high-sensitivity area and a high-porosity ratio area; after determining the standard thickness stratification based on the optimization analysis results, the standard thickness stratification is adaptively adjusted based on the high-sensitivity area and the high-porosity ratio area to generate an adaptive stratification result; and layered backfilling is performed based on the adaptive stratification result.

[0061] In the embodiment of the present application, first, the regional identification of the disturbed soil is carried out. The cone resistance value is obtained by static penetration test on site. and friction ratio ,in Cone head resistance (unit: MPa) reflects the axial reaction force of the soil on the probe. The friction ratio is equal to the percentage of friction resistance to cone resistance, which is used to identify the structural integrity of the soil after disturbance. At the same time, the standard penetration test is combined to obtain the number of blows N, which is used to reflect the compaction degree and bearing capacity change of the foundation soil. In addition, the undrained shear strength of the disturbed soil and the original soil is tested separately through triaxial shear test. If a region Compared with the original sample, it has decreased by more than 30%, and at the same time Lower and The rise indicates that the area is a high sensitivity area, that is, the strength of the soil structure drops sharply and the shear resistance is significantly weakened after the soil structure is disturbed. For pore state identification, the dry density is used. and particle specific gravity Calculate the void ratio n using the formula n= ,in is the density of water (1.0 g / cm³), Measured by density bottle method or hydrometer, if the porosity ratio n of a certain area is higher than the average porosity ratio of the area by more than 20%, and the corresponding If the sensitivity is too low, the area is divided into high porosity area. Through the above steps, high sensitivity area and high porosity area are established.

[0062] Based on the above identification results, combined with the optimal filler gradation scheme obtained in the previous optimization analysis, the layered backfill thickness is set. The optimization analysis not only outputs the specific filler particle ratio, but also gives the porosity, ultimate bearing capacity, compression modulus and compaction evaluation indicators under the corresponding gradation structure. By analyzing these performance data, the optimal compaction effect range corresponding to different filler combinations is clarified, and then the appropriate standard layer thickness is determined. For example, a filler combination with a high fine particle content and high compaction sensitivity is suitable for thinner layers (such as 30cm), while a combination dominated by medium and coarse particles and strong interlocking performance can support a slightly larger layer thickness (such as 50cm). This standard thickness layering scheme serves as a unified initial construction template for the entire region, laying the foundation for further regional adaptive adjustments.

[0063] Based on the standard layering scheme, the layer thickness and filler composition are locally fine-tuned, taking into account the characteristics of the identified disturbance areas. In highly sensitive areas, to prevent further amplification of structural disturbances during compaction, the thickness of the single backfill layer is reduced, typically to 20-25 cm, and the proportion of fine particles is appropriately increased to improve interlayer cohesion and deformation coordination. In areas with high void ratios, the filler's compaction ability and interlayer interlocking properties are improved by thickening the bottom layer (for example, setting the first layer to 60 cm) and increasing the proportion of medium-coarse particles.

[0064] After achieving adaptive stratification, on-site backfill is carried out in layers strictly according to the adjusted thickness and filler structure. Each layer of filler is mechanically spread and then compacted. The compaction equipment is matched to the filler particle size structure. When fine particles are predominant, a high-frequency vibratory rammer is used, while when medium-coarse particles are predominant, an impact roller or double-wheel roller is used. After each layer is compacted, on-site sampling is conducted to test dry density, moisture content, and compaction degree. The compaction degree is determined by calculating the ratio of the measured dry density to the maximum dry density and comparing it to the control standard. Only when the requirements are met can the next layer be constructed. The entire process achieves orderly composite repair of disturbed soil through zoning control, thickness optimization, and a closed-loop quality control system.

[0065] Furthermore, in the method provided in the embodiment of the application, the foundation repair of the offshore pile insertion and extraction area is completed by the layered backfilling and vibration compaction process, and further includes:

[0066] During the vibration compaction process of each layer, the current layer compaction degree is obtained in real time through a nuclear density meter, and the actual porosity is measured by a static penetration tester; if the current layer compaction degree is less than 95% and the actual porosity is greater than the critical porosity, the vibration frequency and amplitude are increased, and the number of rollings is increased; if the current layer compaction degree is greater than or equal to 95% and the actual porosity is less than or equal to the compensation critical porosity, the vibration frequency and amplitude are reduced, and the number of rollings is reduced; after each three layers of compaction are completed, the bearing capacity increment is verified through a plate load test. If the bearing capacity increment is lower than the increment threshold, the secondary optimization of the grading parameters is triggered and the filler ratio is updated.

[0067] In the embodiment of the present application, after each layer of filler is spread and initially vibrated and compacted, a nuclear density meter is used to measure the compaction effect of the layer in real time. The nuclear density meter uses the scattering principle of gamma rays to convert the wet density and moisture content of the filler by detecting the intensity of the rebound rays, and then calculates the dry density. Before the measurement, the maximum dry density of the filler should be determined in advance. Obtained through heavy compaction test, and then through the formula Calculate the compaction degree of the current layer.

[0068] At the same time, the porosity ratio is measured, and the cone resistance value of the layer is obtained by using the cone penetration test (CPT) equipment to detect the current layer. and friction ratio The cone resistance reflects the bearing strength of the soil, and the friction ratio is used to identify the degree of structural disturbance. Combined with the dry density result, use the formula n= Calculate the porosity. Compare the calculated n with the critical porosity of the filler. For comparison, the critical porosity ratio is determined by the dilatancy-contraction turning point under different consolidation stresses in the triaxial shear test, which is used to judge whether the current filling structure is in a stable and dense state.

[0069] According to the above test results, the compaction energy adjustment stage is entered. If it is found that the compaction degree D of the layer is less than 95% and the actual porosity ratio n> This indicates insufficient compaction and the structure has not reached critical density. In this case, the enhanced compaction parameter mode is activated. Construction machinery (such as a double-drum roller or high-frequency vibratory rammer) is used to increase the vibration frequency (Hz) and amplitude (mm), while also increasing the number of rolling passes. This enhances particle rearrangement and interlocking within the layer, improving density and structural strength. If the compaction result is ≥ 95% and the void ratio is ≤ the critical void ratio safety compensation value, the system automatically identifies the situation as "overcompacted." In this case, the vibration frequency, amplitude, and number of rolling passes are reduced to avoid disturbing the structural filler layer or causing particle breakage.

[0070] After compaction of every three layers, a representative area is selected for a plate load test. Using a rigid loading plate with a diameter of 300mm or 600mm, the load is applied step by step to the design load. The settlement at each level is measured, and a load-settlement curve is plotted. The increment in bearing capacity per unit area, Δq, is then extracted. This value is compared to the load-bearing capacity improvement threshold set during the design phase (for example, an increase of at least 50kPa per three layers). If the test value does not reach the preset value, it indicates that the current filler gradation cannot achieve the target bearing capacity under the on-site compaction conditions.

[0071] At this time, the secondary optimization mechanism of gradation parameters is started. This mechanism uses the existing compaction data ( , n, D), CPT response ( 、 ) and measured bearing capacity values ​​are used as input to reconstruct the disturbance correction term and update the bearing capacity evaluation function. Using a genetic algorithm or particle swarm optimization algorithm, the ratio of different particle size components in the filler is re-optimized, outputting a new filler composition. This composition will be used in subsequent backfill batches to replace the current filler mix with insufficient performance, thereby continuously improving the overall compaction response and bearing capacity.

[0072] Furthermore, in the method provided in the embodiment of the application, the foundation repair of the offshore pile insertion and extraction area is completed by the layered backfilling and vibration compaction process, and further includes:

[0073] Pore ​​water pressure sensors and settlement plates are installed on the foundation of the offshore pile insertion and extraction area to perform settlement monitoring within a preset period and generate settlement monitoring results. If the settlement monitoring results cannot meet the preset settlement threshold, a repair abnormality warning is issued.

[0074] In the embodiments of this application, pore-water pressure sensors and settlement plates are first deployed in the offshore pile insertion and extraction area. The pore-water pressure sensors are embedded sensing units, often employing vibrating-wire or strain gauge structures, installed within the backfill soil. They are used to sense the drainage of water and the dissipation of pore pressure during the consolidation process. The settlement plates are positioned between the foundation fill and the bottom of the structure and, in conjunction with liquid-level, fiber-optic, or resistive measurement systems, enable real-time or scheduled data collection of surface settlement.

[0075] The sensor system automatically collects data at a preset interval (e.g., every 24 hours) and uploads it to the backend monitoring platform through the data collection system. The platform cleans and chronologically organizes the collected data, automatically calculating the settlement rate, cumulative settlement, and trend, ultimately generating the settlement monitoring results for the current period. These results reflect the actual settlement performance of a specific area during that period.

[0076] The monitoring results are then compared with the preset settlement threshold, and the actual settlement value of each monitoring point is compared point by point with its corresponding threshold standard. If the settlement of any monitoring point exceeds the preset value or shows a continuous upward trend, it is considered that there is an abnormal settlement risk.

[0077] If the comparison results do not meet the control requirements, a repair anomaly warning is triggered. This warning mechanism notifies management personnel of potential structural stability issues through a graphical monitoring interface, high-priority notification push, or on-site audio and visual alarms, prompting the need for secondary inspection, additional compaction, or other reinforcement measures.

[0078] In the embodiments of the present application, in summary, the embodiments of the present application have at least the following technical effects:

[0079] After analyzing historical drilling data, this application collects additional samples of disturbed soil and original soil in the offshore pile insertion and extraction construction area, establishes a soil combination pattern in the disturbed area based on the sample analysis, and configures the soil in the disturbed area; obtains the total bearing capacity requirement of the mobile platform and the depth of the pile shoe into the mud, and uses the total bearing capacity requirement and the pile shoe into the mud to calculate the pile insertion bearing capacity requirement; takes the pile insertion bearing capacity requirement as the optimization target, configures the bearing capacity evaluation function based on the soil in the disturbed area, performs an optimization analysis of the filler gradation, and establishes the optimization analysis result; controls the filler ratio and particle mixing method based on the optimization analysis result, and completes the foundation repair of the offshore pile insertion and extraction area through layered backfilling and vibration compaction process. The present invention solves the technical problem in the prior art that the strength of the disturbed soil in the well site is reduced due to repeated construction of pile insertion and extraction, resulting in safety hazards such as pile sliding on the platform. By analyzing the combination pattern of disturbed soil and original soil, optimizing the soil gradation based on the bearing capacity requirement, and combining the layered backfilling and vibration compaction process, the mechanical properties of the foundation in the disturbed area are improved, and the safe and stable operation of the platform is guaranteed.

[0080] Example 2 is based on the same inventive concept as the offshore pile-insertion area foundation repair method based on soil gradation optimization in the previous embodiment. Figure 2 As shown, the present application provides an offshore pile insertion and extraction area foundation repair system based on soil gradation optimization. The system and method embodiments in the present application are based on the same inventive concept. The system includes:

[0081] A soil combination pattern establishment module 11 is used to analyze historical drilling data and then collect additional samples of disturbed soil and original soil in the offshore pile insertion and extraction construction area, establish a soil combination pattern in the disturbed area based on the analysis of the sampling samples, and configure the soil in the disturbed area; a pile bearing capacity requirement calculation module 12 is used to obtain the total bearing capacity requirement of the mobile platform and the depth of the pile shoe into the mud, and calculate the pile bearing capacity requirement using the total bearing capacity requirement and the pile shoe depth into the mud; an optimization analysis module 13 is used to use the pile bearing capacity requirement as the optimization target, configure the bearing capacity evaluation function based on the soil in the disturbed area, perform an optimization analysis of the filler gradation, and establish an optimization analysis result; a foundation repair module 14 is used to control the filler ratio and particle mixing method according to the optimization analysis result, and complete the foundation repair of the offshore pile insertion and extraction area through layered backfilling and vibration compaction technology.

[0082] Furthermore, the system is also used to implement the following functions:

[0083] Obtain geological histograms and geotechnical test data from historical drilling data, and collect disturbed soil and undisturbed soil samples through supplementary on-site survey data; divide the physical components and mechanical property zones of the disturbed area through soil particle analysis and microstructure observation; establish particle grading based on soil particle analysis, and use particle grading, microstructure observation results, physical components and mechanical property zones to establish a soil combination model for the disturbed area.

[0084] Furthermore, the system is also used to implement the following functions:

[0085] The disturbed zone correction term is established using the disturbed zone soil; and the bearing capacity evaluation function is configured according to the disturbed zone correction term as follows:

[0086] ;

[0087] in, Characterize the bearing capacity evaluation function, The ultimate bearing capacity of the repaired soil. is the minimum value of the pile bearing capacity requirement, Characterize the shear strength of the repaired soil, Characterizes the minimum anti-slip requirement, is the compression modulus of the repaired soil, Characterizes the minimum value of settlement control requirements, Characterize the critical void ratio, determined based on triaxial tests, is the porosity ratio of the repaired soil, is the index of the disturbance zone correction term, Characterizing the disturbance zone correction term The weight factor of the item, Characterization The correction term of the term, where is the disturbance intensity correction term, is the particle gradation distortion correction term, is the microstructure degradation correction term, are the weight factors of bearing capacity, shear strength, compression modulus and porosity penalty terms respectively.

[0088] Furthermore, the system is also used to implement the following functions:

[0089] The ultimate bearing capacity of the repaired soil is calculated using the following formula: ;in, The undrained shear strength of the repaired pile end. , To measure the undrained shear strength of the repaired soil, is the dimensionless bearing capacity coefficient, is the maximum average contact area of ​​the pile shoe, is the drainage efficiency correction term of the soil beside the pile after repair, is the volume of the pile shoe.

[0090] Furthermore, the system is also used to implement the following functions:

[0091] Establish a stage evaluation for optimization and configure dynamic key parameter weights mapped to the stages. The dynamic key parameters include sensitivity parameters, porosity difference parameters, and non-uniformity coefficient parameters. After constructing the initial population, use the key parameter weights of the initial stage to perform a search update based on the dynamic key parameters, and perform search iterations of the initial population based on the search update results to complete the optimization analysis.

[0092] Furthermore, the system is also used to implement the following functions:

[0093] The fitness of each particle in the initial population is calculated using the carrying capacity evaluation function to generate a fitness calculation result; a particle similarity analysis is performed on each particle in the initial population to generate a similarity cluster; a same-direction search constraint is obtained based on the fitness calculation result and the similarity cluster; a particle with a maximum fitness value in the fitness calculation result is obtained, and a mutation search constraint is established based on the particle with the maximum fitness value; an update search constraint is established based on the key parameter weights of the initial stage and the dynamic key parameters; and a search update is completed based on the same-direction search constraint, the mutation search constraint, and the update search constraint.

[0094] Furthermore, the system is also used to implement the following functions:

[0095] Based on the soil in the disturbed area, regional identification is performed to establish a high-sensitivity area and a high-porosity ratio area; after determining the standard thickness stratification based on the optimization analysis results, the standard thickness stratification is adaptively adjusted based on the high-sensitivity area and the high-porosity ratio area to generate an adaptive stratification result; and layered backfilling is performed based on the adaptive stratification result.

[0096] Furthermore, the system is also used to implement the following functions:

[0097] During the vibration compaction process of each layer, the current layer compaction degree is obtained in real time through a nuclear density meter, and the actual porosity is measured by a static penetration tester; if the current layer compaction degree is less than 95% and the actual porosity is greater than the critical porosity, the vibration frequency and amplitude are increased, and the number of rollings is increased; if the current layer compaction degree is greater than or equal to 95% and the actual porosity is less than or equal to the compensation critical porosity, the vibration frequency and amplitude are reduced, and the number of rollings is reduced; after each three layers of compaction are completed, the bearing capacity increment is verified through a plate load test. If the bearing capacity increment is lower than the increment threshold, the secondary optimization of the grading parameters is triggered and the filler ratio is updated.

[0098] Furthermore, the system is also used to implement the following functions:

[0099] Pore ​​water pressure sensors and settlement plates are installed on the foundation of the offshore pile insertion and extraction area to perform settlement monitoring within a preset period and generate settlement monitoring results. If the settlement monitoring results cannot meet the preset settlement threshold, a repair abnormality warning is issued.

[0100] It should be noted that the order in which the embodiments of the present application are presented is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. Furthermore, the foregoing descriptions of specific embodiments of this specification are provided. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential sequence shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0101] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

[0102] This specification and drawings are merely illustrative of the present application and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Obviously, those skilled in the art may make various modifications and variations to this application without departing from the scope of this application. Thus, this application is intended to include such modifications and variations as fall within the scope of this application and its equivalents.

Claims

1. A method for repairing offshore pile-insertion areas based on soil gradation optimization, characterized in that: The method comprises: After analyzing historical drilling data, additional samples of disturbed soil and undisturbed soil were collected from the offshore pile insertion and extraction construction area. Based on the analysis of the sampled soils, a soil combination model for the disturbed area was established to configure the soil in the disturbed area. Obtaining the total bearing capacity requirement of the mobile platform and the depth of the pile shoe inserted into the mud, and calculating the pile bearing capacity requirement using the total bearing capacity requirement and the depth of the pile shoe inserted into the mud; Taking the bearing capacity requirement of the pile as the optimization target, after configuring the bearing capacity evaluation function of the soil in the disturbed area, an optimization analysis of the filler gradation is performed to establish the optimization analysis result; After controlling the filler ratio and particle mixing method based on the optimization analysis results, the foundation repair in the offshore pile insertion and extraction area was completed through layered backfilling and vibration compaction processes; After analyzing the historical drilling data, additional samples of disturbed soil and undisturbed soil in the offshore pile insertion and extraction construction area are collected. Based on the analysis of the sampled samples, a soil combination model of the disturbed area is established, including: Obtain geological histograms and geotechnical test data from historical borehole data, supplemented by on-site survey data, and collect disturbed and undisturbed soil samples; Through soil particle analysis and microstructure observation, the physical components and mechanical properties of the disturbance zone are divided into zones; Establish particle grading based on soil particle analysis, and establish soil composition patterns in the disturbance zone using particle grading, microstructural observations, physical components, and mechanical properties. The configuration of the bearing capacity evaluation function based on the soil in the disturbance zone includes: establishing a disturbance zone correction term using the disturbance zone soil; The carrying capacity evaluation function is configured according to the disturbance zone correction term as follows: ;in, Characterize the bearing capacity evaluation function, The ultimate bearing capacity of the repaired soil. is the minimum value of the pile bearing capacity requirement, Characterize the shear strength of the repaired soil, Characterizes the minimum anti-slip requirement, is the compression modulus of the repaired soil, Characterizes the minimum value of settlement control requirements, Characterize the critical void ratio, determined based on triaxial tests, is the porosity ratio of the repaired soil, is the index of the disturbance zone correction term, Characterizing the disturbance zone correction term The weight factor of the item, Characterization The correction term of the term, where is the disturbance intensity correction term, is the particle gradation distortion correction term, is the microstructure degradation correction term, are the weight factors of bearing capacity, shear strength, compression modulus, and porosity penalty terms respectively; The ultimate bearing capacity of the repaired soil is calculated using the following formula: ； in, The undrained shear strength of the pile end after repair. , To measure the undrained shear strength of the repaired soil, is the dimensionless bearing capacity coefficient, is the maximum average contact area of ​​the pile shoe, is the drainage efficiency correction term of the soil beside the pile after repair, is the volume of the pile shoe; The above-mentioned method of completing the foundation repair of the offshore pile insertion and extraction area through layered backfilling and vibration compaction process includes: Perform regional identification based on the soil in the disturbed area, and establish high-sensitivity areas and high-porosity areas; After determining the standard thickness layer according to the optimization analysis result, performing adaptive adjustment on the standard thickness layer according to the high sensitivity area and the high porosity ratio area to generate an adaptive layer result; Layered backfilling is performed based on the adaptive layering result.

2. The offshore pile-insertion area foundation repair method based on soil gradation optimization according to claim 1 is characterized in that: The optimization analysis of filler gradation includes: Establishing a stage evaluation for optimization and configuring dynamic key parameter weights mapped to the stages, wherein the dynamic key parameters include a sensitivity parameter, a porosity difference parameter, and a non-uniformity coefficient parameter; After the initial population is constructed, the key parameter weights in the initial stage are used to perform a search update based on the dynamic key parameters, and the search iteration of the initial population is performed according to the search update result to complete the optimization analysis.

3. The offshore pile-insertion area foundation repair method based on soil gradation optimization according to claim 2 is characterized in that: The method of utilizing the key parameter weights in the initial stage to perform search updates based on the dynamic key parameters includes: Calculating the fitness of each particle in the initial population using the carrying capacity evaluation function to generate a fitness calculation result; performing particle similarity analysis on each particle in the initial population to generate similarity clusters; Obtaining same-direction search constraints according to the fitness calculation result and the similarity clustering; Obtaining a particle with a maximum fitness value from the fitness calculation results, and establishing a mutation search constraint based on the particle with the maximum fitness value; Establishing update search constraints according to the key parameter weights of the initial stage and the dynamic key parameters; The search update is completed based on the same-direction search constraint, the mutation search constraint, and the update search constraint.

4. The offshore pile-insertion area foundation repair method based on soil gradation optimization according to claim 1 is characterized in that: The completion of the offshore pile insertion and extraction area foundation repair by layered backfilling and vibration compaction process also includes: During the vibration compaction process of each layer, the current layer compaction degree is obtained in real time by a nuclear density meter, and the actual porosity ratio is measured by a static penetration tester; If the current layer compaction degree is less than 95% and the actual void ratio is greater than the critical void ratio, then the vibration frequency and amplitude are increased, and the number of rolling times is increased; If the current layer compaction degree is greater than or equal to 95% and the actual void ratio is less than or equal to the compensation critical void ratio, reduce the vibration frequency and amplitude, and reduce the number of rolling times; After completing three layers of compaction, the bearing capacity increment is verified through a flat plate load test. If the bearing capacity increment is lower than the increment threshold, the secondary optimization of the grading parameters is triggered and the filler ratio is updated.

5. The offshore pile-insertion area foundation repair method based on soil gradation optimization according to claim 1 is characterized in that: The completion of the offshore pile insertion and extraction area foundation repair by layered backfilling and vibration compaction process also includes: Install pore water pressure sensors and settlement plates on the foundation of the offshore pile insertion and extraction area, monitor the settlement within a preset period, and generate settlement monitoring results; If the settlement monitoring result fails to meet the preset settlement threshold, a repair abnormality warning will be issued.

6. A system for repairing offshore pile-insertion areas based on soil gradation optimization, which adopts the method for repairing offshore pile-insertion areas based on soil gradation optimization according to claim 1, characterized in that: The system comprises: The soil combination model establishment module is used to analyze historical drilling data, collect additional disturbed soil and undisturbed soil samples in the offshore pile insertion and extraction construction area, and establish a soil combination model for the disturbed area based on the sample analysis to configure the soil in the disturbed area; A pile bearing capacity requirement calculation module is used to obtain the total bearing capacity requirement of the mobile platform and the depth of the pile shoe inserted into the mud, and calculate the pile bearing capacity requirement using the total bearing capacity requirement and the depth of the pile shoe inserted into the mud; An optimization analysis module is used to perform an optimization analysis of filler gradation based on the pile bearing capacity requirement as an optimization target and a bearing capacity evaluation function configured on the soil in the disturbed area, and to establish an optimization analysis result; The foundation repair module is used to control the filler ratio and particle mixing method according to the optimization analysis results, and then complete the foundation repair of the offshore pile insertion and extraction area through layered backfilling and vibration compaction processes.

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