An analytical method for testing the bearing characteristics of vibro-replacement crushed stone pile composite foundation

Abstract

The present invention discloses an analysis method for detecting the bearing characteristics of a vibro-compacted gravel pile composite foundation, which relates to the technical field of bearing characteristics analysis, and includes the following steps: S1, clarifying the main objectives of the bearing characteristics analysis of a vibro-compacted gravel pile composite foundation; S2, selecting geotechnical engineering analysis software; S3, obtaining the physical and mechanical parameters of soil layers and gravel materials; S4, applying corresponding loads in the model; S5, extracting key data of foundation bearing capacity, settlement, and stress distribution from the simulation software; S6, making optimization suggestions for the identified problems; S7, organizing the data and results obtained during the simulation analysis. The main advantage of the present invention is that a complete and systematic analysis process is formed, combining indoor tests and field tests to obtain the physical and mechanical parameters of soil layers and gravel materials, and at the same time, through sensitivity analysis, finding out the parameters that have a greater impact on the bearing characteristics of the foundation, ensuring the accuracy and reliability of the analysis results.

Description

Technical Field

[0001] The invention relates to the technical field of bearing characteristic analysis, and in particular to an analysis method for detecting the bearing characteristic of a vibro-compacted gravel pile composite foundation. Background Art

[0002] Foundation treatment refers to the engineering and technical measures taken to improve the bearing capacity of the foundation supporting the building, and to improve its deformation performance or impermeability. There are many methods of foundation treatment, such as soil replacement cushion method, deep compaction method, drainage consolidation method, chemical reinforcement method, reinforcement method, etc. In recent decades, the foundation treatment technology at home and abroad has developed rapidly, from construction methods, construction technology to design theory. Among them, gravel pile composite foundation reinforcement soil is one of the most widely used foundation treatment methods.

[0003] In the existing analysis process of the bearing characteristics of gravel pile composite foundation, the theoretical and experimental research of gravel piles has developed rapidly, and many results worthy of reference have been achieved. However, there are still many problems that have not been solved, and the research on its application in soft soil foundations needs to be deepened. The research on foundation treatment of soft soil in the west has become more urgent. Therefore, it is necessary to propose a bearing characteristics analysis method for vibro-compacted gravel pile composite foundation to solve the problems of foundation research.

[0004] The above scheme requires the proposal of a method for analyzing the bearing characteristics of vibro-compacted gravel pile composite foundation. This method involves studying the reinforcement mechanism technology of gravel pile composite foundation, studying various construction process technologies of gravel pile, simulating and analyzing gravel pile reinforcement foundation based on finite element analysis, and comparing and analyzing the calculated settlement of composite foundation with the actual measurement. Through engineering practice, process parameter comparison and optimization, quality control standards and safety and environmental protection measures are analyzed and controlled, so as to more accurately evaluate the bearing capacity and deformation characteristics of the foundation.

[0005] However, in the process of using the bearing characteristics analysis method of vibro-compacted gravel pile composite foundation, when calculating the settlement of gravel pile composite foundation roadbed, the embankment is loaded step by step through the process. Since the embankment loading process has multiple stages and factors, these factors are often difficult to fully consider in the settlement calculation, resulting in differences between the calculation results and the actual situation. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings existing in the prior art and to propose an analysis method for detecting the bearing characteristics of a vibro-compacted gravel pile composite foundation, which solves the problems of high cost and great limitations of the existing bearing capacity detection methods.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] An analysis method for detecting the bearing characteristics of a vibro-replacement crushed stone pile composite foundation comprises the following steps:

[0009] S1. Clarify the main objectives of the bearing characteristics analysis of vibro-stone pile composite foundation, including assessment of bearing capacity, settlement control, stability analysis, and collation of relevant information on the geological conditions, soil layer distribution, groundwater level, and historical earthquake records of the project site;

[0010] S2. According to the purpose of analysis, select geotechnical engineering analysis software, and build a three-dimensional numerical model including soil layers, gravel piles and surrounding soil based on geological survey data, and clarify the boundary conditions of the model, including load application method, foundation treatment range, and drainage conditions;

[0011] S3. Obtain the physical and mechanical parameters of soil and gravel materials, including density, elastic modulus, Poisson's ratio, and internal friction angle, through indoor tests or field tests, and compare the collected parameters with empirical values ​​or similar engineering cases;

[0012] S4. According to the design requirements and actual working conditions, the corresponding loads are applied to the model, including static loads, dynamic loads, and temperature loads. The model after the loads are applied is simulated and analyzed by numerical simulation software to obtain the key data of the bearing capacity, settlement, and stress distribution of the foundation;

[0013] S5. Extract key data of foundation bearing capacity, settlement, and stress distribution from the simulation software, analyze the extracted data, evaluate whether the bearing characteristics of the foundation meet the design requirements, and conduct sensitivity analysis on key parameters;

[0014] S6. Identify problems or deficiencies in the bearing characteristics of the foundation based on the analysis results, and make optimization suggestions for the identified problems, including adjusting the diameter, spacing, and length of the gravel piles, and re-simulating and analyzing the optimized design;

[0015] S7. Organize the data and results obtained during the simulation analysis process, and write an analysis report based on the organized data and results, including the analysis purpose, methods, results, evaluation and optimization suggestions, and summarize and discuss the analysis results.

[0016] As a further improvement of the present invention, in step S1, the bearing capacity is evaluated by applying vertical pressure step by step through a rigid pressure plate, observing the settlement of the test pressure plate over time, the settlement control is to set settlement observation points at key positions before and after foundation treatment, the stability analysis is to use a drilling rig to conduct geological exploration and sample and analyze the physical and mechanical properties of the foundation soil, and the data is sorted after the sampling and analysis, and the data includes soil layer distribution, groundwater level and soil shear strength. Thus, the stability index of the foundation is calculated based on the geological exploration data using data analysis software, the stability of the foundation is evaluated based on the calculation results, and necessary reinforcement measures or suggestions are proposed.

[0017] As a further improvement of the present invention, in step S2, the geological survey data includes soil layer distribution, soil weight, shear strength, internal friction angle, cohesion, groundwater level and historical earthquake record information, and the three-dimensional numerical model is created by PLAXIS3D software, in which the thickness, weight, shear strength, internal friction angle and cohesion parameters of each soil layer are defined, and the surrounding soil model is established according to the PLAXIS3D software. Thus, through multiple iterative calculations and result analysis, the model parameters and boundary conditions are gradually optimized until a reasonable and accurate analysis result is obtained.

[0018] As a further improvement of the present invention, in step S3, the indoor test to obtain physical and mechanical parameters requires the collection of representative soil and gravel samples from the site, the samples collected on site must ensure that the samples are not contaminated or damaged during the collection process, the processing of the collected samples includes cutting, trimming and marking, the field test to obtain physical and mechanical parameters requires the arrangement of test points on site according to the test requirements, and the physical and mechanical parameters obtained by the indoor test and the physical and mechanical parameters obtained by the field test are used for comparative verification. Thus, the parameters obtained by the indoor test and the field test are compared with the empirical values ​​or similar engineering cases. If the difference is large, it is necessary to analyze the cause and make necessary adjustments or retests.

[0019] As a further improvement of the present invention, in step S4, the numerical simulation software is used to ensure that the three-dimensional numerical model established in S2 is verified by S3, the load is applied to the model according to the design requirements and actual working conditions, the numerical simulation analysis is to set the analysis steps in the numerical simulation software, the numerical simulation analysis includes convergence criteria, number of iterations and time step, and the result of the simulation analysis is output in the form of a chart or cloud map. Thus, through simulation analysis, the bearing capacity of the foundation under a specific load is obtained, the settlement process of the foundation under load is simulated, the settlement amount and its change curve over time are obtained, and the stress distribution inside the foundation is analyzed.

[0020] As a further improvement of the present invention, the load includes static load and dynamic load, the static load includes building deadweight, live load and soil pressure, and the dynamic load includes traffic load, wind load and earthquake load. This helps to more accurately calculate the impact of each load on the structure and ensure the accuracy and reliability of the design.

[0021] As a further improvement of the present invention, in step S5, the simulation analysis is performed by PLAXIS, ABAQUS or MIDAS / GTS, the data analysis includes foundation bearing capacity analysis, settlement analysis and stress distribution analysis, and the sensitivity analysis determines key parameters according to the actual situation of the foundation and design requirements, and the key parameters include elastic modulus, Poisson's ratio, internal friction angle and cohesion of the soil. Thus, the influence of each parameter on the foundation bearing characteristics is analyzed, and the parameters with higher sensitivity are found. According to the sensitivity analysis results, the rationality of the foundation design is evaluated, and the parameters with higher sensitivity are optimized and adjusted to improve the bearing capacity and stability of the foundation.

[0022] As a further improvement of the present invention, in step S6, the simulation analysis is used to calculate the key indicators of foundation bearing capacity, settlement and stress distribution, and after the simulation is completed, the optimization effect is verified, and the optimization result is compared with the original result, and the comparison is used to make the optimization effect meet the design requirements, so as to achieve the best effect of improving the foundation bearing capacity, reducing the settlement and improving the stress distribution.

[0023] As a further improvement of the present invention, in step S7, the data is drawn by Matplotlib, Seaborn, Tableau chart drawing tools, the charts include line charts, scatter plots, bar charts and stress cloud charts, and the data tables and charts are used to display the results of the simulation analysis. Thus, the results of the simulation analysis can be intuitively displayed through data tables and charts, making complex data and information clear at a glance.

[0024] As a further improvement of the present invention, the symbol for the foundation bearing capacity is N cf , the N cf The specific calculation formula is:

[0025] N cf =a1b1mN pf +a2b2(1-m)N sf or N cf =a2N sf [1++m(n-1)],

[0026] a1 is the correction coefficient of the bearing capacity of the gravel pile, b1 is the ultimate strength of the gravel pile, m is the area replacement rate, N pfis the ultimate bearing capacity of a single gravel pile, a2 is the correction factor for the difference between the natural bearing capacity and the bearing capacity of the soil between the piles, b2 is the ultimate strength of the soil between the piles, and N sf is the ultimate bearing capacity of natural foundation soil, and n is the allowable variation value during construction.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The analysis method proposed in the present invention starts from clarifying the analysis target, to data collection, model establishment, parameter acquisition, simulation analysis, data extraction and analysis, and then to optimization design and report writing, forming a complete and systematic analysis process. Numerical simulation software is used to establish and simulate the foundation model, and accurate calculations and predictions are performed based on actual geological conditions and working conditions. The physical and mechanical parameters of soil layers and gravel materials are obtained by combining indoor tests and field tests. At the same time, through sensitivity analysis, the parameters that have a greater impact on the bearing characteristics of the foundation are found. The present invention also includes bearing capacity testing, settlement observation, stability analysis and gravel pile parameter sensitivity analysis. Multiple experiments and verification steps ensure the accuracy and reliability of the analysis results.

[0029] 2. In the analysis method proposed by the present invention, the settlement of the composite foundation roadbed of the stone pile is simulated and calculated by large-scale finite element software, and the step-by-step loading process of the embankment is replaced by the mode of applying uniform force step by step, thereby obtaining the time curve and partial settlement law of the settlement of the composite foundation roadbed of the stone pile. By applying uniform force step by step, the process of step-by-step loading of the actual embankment can be simulated, so that the simulation result is closer to the actual situation, thereby improving the accuracy of settlement prediction. And the finite element software can comprehensively consider the influence of various factors such as the arrangement and performance of the foundation material, the stone pile, and the loading method on the settlement, so that the prediction result is more comprehensive and reliable. And the simulation calculation can obtain the settlement time curve of the composite foundation roadbed of the stone pile, revealing the change law of settlement over time, which is helpful to evaluate the stability and safety of the foundation, and by comparing the simulation results under different conditions, the influence degree of each factor on the settlement can be analyzed, providing guidance for optimizing design and construction.

[0030] 3. In the analysis method proposed in the present invention, the reinforcement mechanism of the gravel pile is first studied. Then the software is used to simulate the reinforcement process of the gravel pile in the soft soil roadbed, and numerical analysis is performed, and the bearing mechanism of the gravel pile composite foundation is further discussed. Then on-site monitoring is carried out to monitor the settlement of the pile foundation and the settlement during the roadbed construction process. The settlement observation results of "untreated" and "gravel pile composite foundation treatment" are compared to obtain the effectiveness of the gravel pile reinforcement of the soft soil foundation. Finally, a summary is made by comparing on-site monitoring and numerical analysis. On the basis of clarifying the reinforcement mechanism, the software is used to simulate the reinforcement process of the gravel pile in the soft soil roadbed, which can more intuitively show the interaction between the gravel pile and the soft soil, as well as the effect of the gravel pile on the foundation bearing capacity. Moreover, through software simulation, numerical analysis can be performed to predict key indicators such as the foundation bearing capacity and settlement after the gravel pile reinforcement. This prediction method has high accuracy and can provide a reliable reference for engineering design and construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 It is a schematic diagram of the steps of the present invention. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0034] An analysis method for detecting the bearing characteristics of a vibro-replacement crushed stone pile composite foundation comprises the following steps:

[0035] S1. Define the main objectives of the analysis of the bearing characteristics of the vibro-stone pile composite foundation, including the assessment of bearing capacity, settlement control, and stability analysis, and organize the geological conditions, soil layer distribution, groundwater level, and historical earthquake records of the project site. The bearing capacity is assessed by applying vertical pressure step by step through the rigid bearing plate, and the settlement of the test bearing plate over time is observed. Settlement control is to set settlement observation points at key locations before and after foundation treatment. Stability analysis is to use a drilling rig to conduct geological exploration and sample and analyze the physical and mechanical properties of the foundation soil. After sampling and analysis, the data is organized, including soil layer distribution, groundwater level, and soil shear strength.

[0036] S2. According to the purpose of analysis, geotechnical engineering analysis software is selected. According to the geological survey data, a three-dimensional numerical model including soil layers, gravel piles and surrounding soil is established, and the boundary conditions of the model are clarified, including the load application method, foundation treatment range, and drainage conditions. The geological survey data include soil layer distribution, soil density, shear strength, internal friction angle, cohesion, groundwater level and historical earthquake record information. The three-dimensional numerical model is created by PLAXIS3D software. The thickness, density, shear strength, internal friction angle and cohesion parameters of each soil layer are defined in PLAXIS3D software, and the surrounding soil model is established according to PLAXIS3D software.

[0037] S3. Obtain the physical and mechanical parameters of soil and gravel materials through indoor or field tests, including density, elastic modulus, Poisson's ratio, and internal friction angle, and compare the collected parameters with empirical values ​​or similar engineering cases. To obtain physical and mechanical parameters in indoor tests, representative soil and gravel samples must be collected from the site. Samples collected on site must ensure that the samples are not contaminated or damaged during the collection process. The processing of collected samples includes cutting, trimming, and marking. To obtain physical and mechanical parameters in field tests, test points must be arranged on site according to the test requirements. Physical and mechanical parameters obtained in indoor tests and field tests are used for comparative verification.

[0038] S4. According to the design requirements and actual working conditions, apply corresponding loads to the model, including static loads, dynamic loads, and temperature loads. Use numerical simulation software to simulate and analyze the model after the loads are applied to obtain key data on the bearing capacity, settlement, and stress distribution of the foundation. Numerical simulation software is used to ensure that the three-dimensional numerical model established in S2 is verified by S3. The load application is determined based on the design requirements and actual working conditions and applied to the model. Numerical simulation analysis is to set the analysis steps in the numerical simulation software. Numerical simulation analysis includes convergence criteria, number of iterations, and time step. The results of the simulation analysis are output in the form of charts or cloud maps. Loads include static loads and dynamic loads. Static loads include the building's own weight, live loads, and soil pressure. Dynamic loads include traffic loads, wind loads, and seismic loads.

[0039] S5. Extract the key data of foundation bearing capacity, settlement, and stress distribution from the simulation software, analyze the extracted data, evaluate whether the bearing characteristics of the foundation meet the design requirements, and perform sensitivity analysis on key parameters. The simulation analysis is performed using PLAXIS, ABAQUS, or MIDAS / GTS. The data analysis includes foundation bearing capacity analysis, settlement analysis, and stress distribution analysis. The sensitivity analysis determines the key parameters based on the actual conditions of the foundation and the design requirements. The key parameters include the elastic modulus, Poisson's ratio, internal friction angle, and cohesion of the soil.

[0040] S6. According to the analysis results, identify the problems or deficiencies in the foundation bearing characteristics, and make optimization suggestions for the identified problems, including adjusting the diameter, spacing, and length of the gravel piles, and re-simulating and analyzing the optimized design. The simulation analysis is used to calculate the key indicators of foundation bearing capacity, settlement, and stress distribution. After the simulation is completed, the optimization effect is verified and the optimization results are compared with the original results. The comparison is used to ensure that the optimization effect meets the design requirements. The symbol for foundation bearing capacity is N cf , N cf The specific calculation formula is:

[0041] N cf =a1b1mN pf +a2b2(1-m)N sf or N cf =a2N sf [1+m(n-1)],

[0042] a1 is the correction coefficient of the bearing capacity of the gravel pile, b1 is the ultimate strength of the gravel pile, m is the area replacement rate, N pf is the ultimate bearing capacity of a single gravel pile, a2 is the correction factor for the difference between the natural bearing capacity and the bearing capacity of the soil between the piles, b2 is the ultimate strength of the soil between the piles, N sf is the ultimate bearing capacity of natural foundation soil, and n is the allowable variation value during construction.

[0043] S7. Organize the data and results obtained during the simulation analysis, and write an analysis report based on the organized data and results, including the purpose, method, results, evaluation and optimization suggestions of the analysis, and summarize and discuss the analysis results. The data is drawn using Matplotlib, Seaborn, and Tableau chart drawing tools. The charts include line charts, scatter charts, bar charts, and stress cloud charts. Data tables and charts are used to display the results of the simulation analysis.

[0044] Example

[0045] The purpose of the application of the bearing characteristics analysis method of vibro-replacement crushed stone pile composite foundation in the research of the technology of crushed stone pile composite foundation reinforcement mechanism is to further develop and summarize the researchers of the enterprise technology center on the basis of the practical experience obtained, repeatedly consider various process parameters, select and optimize the process parameters through engineering practice, analyze and control the quality control standards and safety and environmental protection measures, and provide a scientific basis for engineering design and construction. Therefore, the following experiments are designed:

[0046] 1. Purpose of the experiment

[0047] The bearing characteristics of vibro-stone pile composite foundation, including bearing capacity, settlement control and stability, were verified through experiments, and the influence of parameters such as diameter, spacing and length of stone piles on the bearing characteristics of the foundation was explored;

[0048] 2. Experimental Equipment and Materials

[0049] Vibrator: used for the construction of vibratory crushed stone piles;

[0050] Crushed stone material: Select crushed stone that meets the design requirements as the pile material;

[0051] Rigid bearing plate: used to apply vertical pressure and observe the settlement of the test bearing plate;

[0052] Level: used to observe foundation settlement;

[0053] Drilling rig: used for geological exploration and sampling;

[0054] Indoor test equipment: including density tester, elastic modulus tester, Poisson's ratio tester and internal friction angle tester;

[0055] Data recording equipment: such as computers, data acquisition systems, etc.;

[0056] 3. Experimental steps and parameter settings

[0057] Experiment 1: Construction and bearing capacity test of vibro-stone piles

[0058] (1) Construction preparation:

[0059] Determine the diameter, spacing and length of the gravel piles according to the design requirements;

[0060] Clean up the construction site and ensure that the construction area is flat;

[0061] (2) Vibro-stone pile construction:

[0062] Use a vibrator to vibrate the crushed stone material into the soil to form a crushed stone pile;

[0063] During the construction process, record parameters such as the number of vibrations and vibration time;

[0064] (3) Bearing capacity test:

[0065] After the piles are formed, vertical pressure (load) is applied step by step through the rigid bearing plate;

[0066] After each level of load is added, the settlement is measured and recorded every 30 minutes;

[0067] When the settlement is less than 0.25 mm per hour, the lower load can be added;

[0068] Termination loading conditions include a sudden increase in settlement, soil extrusion, cumulative settlement greater than 10% of the platen width or diameter, and total load exceeding twice the design requirement.

[0069] Unloading is carried out in 3 levels, and the rebound volume is recorded every 15 minutes, and then recorded again after half an hour;

[0070] (4) Data recording and analysis, see Table 1:

[0071] Record the settlement and rebound at each load level;

[0072] Calculate the characteristic value of composite foundation bearing capacity based on recorded data;

[0073] Table 1 Data of vibro-stone pile construction and bearing capacity test

[0074]

[0075]

[0076] In summary, through the bearing capacity test, the bearing capacity characteristic value of the composite foundation was obtained, and the design requirements and actual test results were compared to evaluate whether the bearing capacity of the foundation meets the requirements;

[0077] Experiment 2: Settlement Observation and Stability Analysis

[0078] (1) Setting of settlement observation points:

[0079] Set up settlement observation points at key locations before and after foundation treatment;

[0080] Use a level to regularly observe the settlement at each observation point and record it;

[0081] (2) Stability analysis:

[0082] Use drilling rigs to conduct geological exploration and take samples to analyze the physical and mechanical properties of foundation soil;

[0083] Organize exploration data, including soil layer distribution, groundwater level, soil shear strength, etc.;

[0084] Using data analysis software, calculate the stability index of the foundation based on geological exploration data;

[0085] (3) Data recording and analysis, see Table 2:

[0086] Record the settlement data for each observation;

[0087] Analyze foundation settlement trends and evaluate treatment effects;

[0088] Evaluate the stability of the foundation according to the stability index and propose necessary reinforcement measures or suggestions;

[0089] Table 2 Settlement observation and stability analysis data table

[0090]

[0091] Conclusion,Through settlement observation and stability analysis, the settlement trend and stability index of the foundation are obtained, which are used to evaluate the effect of foundation treatment and put forward necessary reinforcement measures or suggestions;

[0092] Experiment 3: Sensitivity analysis of gravel column parameters

[0093] (1) Parameter settings:

[0094] The diameter, spacing and length of the gravel piles were selected as key parameters for sensitivity analysis;

[0095] Set a reasonable range of variation for each parameter to simulate the bearing characteristics of the foundation under different working conditions;

[0096] (2) Simulation analysis:

[0097] Use numerical simulation software to build foundation models;

[0098] Re-run the simulation analysis under different values ​​of each parameter;

[0099] Extract key data such as foundation bearing capacity, settlement, stress distribution, etc.

[0100] (3) Data recording and analysis, see Table 3:

[0101] Compare the simulation results under different parameter values;

[0102] Analyze the influence of each parameter on the bearing characteristics of the foundation;

[0103] Find out the parameters with higher sensitivity and make optimization suggestions;

[0104] Table 3 Gravel pile parameter sensitivity analysis data table

[0105]

[0106] Conclusion,Through sensitivity analysis, the influence of each parameter on the bearing characteristics of the foundation is obtained, the parameters with higher sensitivity are found, and optimization suggestions are put forward to guide the design of gravel piles in actual engineering;

[0107] In summary, in the treatment of soft soil foundation, the vibro-compacted gravel pile composite foundation reinforcement of the present invention is a widely used and effective foundation treatment method. The method of the present invention can better evaluate and optimize the bearing characteristics of the gravel pile composite foundation, and provide a scientific basis and technical support for highway construction and foundation treatment. Especially in infrastructure construction, the application of this method will become more important and urgent.

[0108] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An analytical method for detecting the bearing characteristics of a vibro-replacement crushed stone pile composite foundation, comprising the following steps: S1. Clarify the main objectives of the bearing characteristics analysis of vibro-stone pile composite foundation, including assessment of bearing capacity, settlement control, stability analysis, and collation of relevant information on the geological conditions, soil layer distribution, groundwater level, and historical earthquake records of the project site; S2. According to the purpose of analysis, select geotechnical engineering analysis software, and build a three-dimensional numerical model including soil layers, gravel piles and surrounding soil based on geological survey data, and clarify the boundary conditions of the model, including load application method, foundation treatment range, and drainage conditions; S3. Obtain the physical and mechanical parameters of soil and gravel materials, including density, elastic modulus, Poisson's ratio, and internal friction angle, through indoor tests or field tests, and compare the collected parameters with empirical values ​​or similar engineering cases; S4. According to the design requirements and actual working conditions, the corresponding loads are applied to the model, including static loads, dynamic loads, and temperature loads. The model after the loads are applied is simulated and analyzed by numerical simulation software to obtain the key data of the bearing capacity, settlement, and stress distribution of the foundation; S5. Extract key data of foundation bearing capacity, settlement, and stress distribution from the simulation software, analyze the extracted data, evaluate whether the bearing characteristics of the foundation meet the design requirements, and conduct sensitivity analysis on key parameters; S6. Identify problems or deficiencies in the bearing characteristics of the foundation based on the analysis results, and make optimization suggestions for the identified problems, including adjusting the diameter, spacing, and length of the gravel piles, and re-simulating and analyzing the optimized design; S7. Organize the data and results obtained during the simulation analysis process, and write an analysis report based on the organized data and results, including the analysis purpose, methods, results, evaluation and optimization suggestions, and summarize and discuss the analysis results.

2. The analysis method for detecting the bearing characteristics of vibro-stone pile composite foundation according to claim 1, characterized in that: In step S1, the bearing capacity is evaluated by applying vertical pressure step by step through a rigid pressure plate, and the settlement of the test pressure plate over time is observed. The settlement control is to set settlement observation points at key positions before and after foundation treatment. The stability analysis is to conduct geological exploration using a drilling rig and sample and analyze the physical and mechanical properties of the foundation soil. After the sampling and analysis, the data is sorted, and the data includes soil layer distribution, groundwater level and soil shear strength.

3. The analysis method for detecting the bearing characteristics of vibro-stone pile composite foundation according to claim 2 is characterized in that: In step S2, the geological survey data includes soil layer distribution, soil density, shear strength, internal friction angle, cohesion, groundwater level and historical earthquake record information. The three-dimensional numerical model is created by PLAXIS3D software. The thickness, density, shear strength, internal friction angle and cohesion parameters of each soil layer are defined in the PLAXIS3D software, and the surrounding soil model is established according to the PLAXIS3D software.

4. The analysis method for detecting the bearing characteristics of vibro-stone pile composite foundation according to claim 3 is characterized in that: In step S3, the indoor test to obtain physical and mechanical parameters requires collecting representative soil and gravel samples from the site. The samples collected on site must ensure that the samples are not contaminated or damaged during the collection process. The processing of the collected samples includes cutting, trimming and marking. The on-site test to obtain physical and mechanical parameters requires arranging test points on site according to the test requirements. The physical and mechanical parameters obtained by the indoor test and the physical and mechanical parameters obtained by the on-site test are used for comparative verification.

5. The analysis method for detecting the bearing characteristics of vibro-stone pile composite foundation according to claim 4, characterized in that: In step S4, the numerical simulation software is used to ensure that the three-dimensional numerical model established in S2 is verified by S3, the load application is determined on the model according to the design requirements and actual working conditions, the numerical simulation analysis is to set the analysis steps in the numerical simulation software, the numerical simulation analysis includes convergence criteria, number of iterations and time step, and the results of the simulation analysis are output in the form of charts or cloud maps.

6. The analysis method for detecting the bearing characteristics of vibro-stone pile composite foundation according to claim 5, characterized in that: The loads include static loads and dynamic loads. The static loads include the building's own weight, live loads and soil pressure, and the dynamic loads include traffic loads, wind loads and earthquake loads.

7. The analysis method for detecting the bearing characteristics of vibro-stone pile composite foundation according to claim 5, characterized in that: In step S5, the simulation analysis is performed through PLAXIS, ABAQUS or MIDAS / GTS, the data analysis includes foundation bearing capacity analysis, settlement analysis and stress distribution analysis, and the sensitivity analysis determines key parameters according to the actual situation of the foundation and design requirements, and the key parameters include elastic modulus, Poisson's ratio, internal friction angle and cohesion of the soil.

8. The analysis method for detecting the bearing characteristics of vibro-stone pile composite foundation according to claim 7, characterized in that: In step S6, the simulation analysis is used to calculate key indicators of foundation bearing capacity, settlement and stress distribution. After the simulation is completed, the optimization effect is verified and the optimization result is compared with the original result. The comparison is used to ensure that the optimization effect meets the design requirements.

9. The analysis method for detecting the bearing characteristics of vibro-stone pile composite foundation according to claim 8, characterized in that: In step S7, the data is plotted using Matplotlib, Seaborn, and Tableau chart drawing tools. The charts include line graphs, scatter graphs, bar graphs, and stress cloud graphs. The data tables and charts are used to display the results of the simulation analysis.

10. The analysis method for detecting the bearing characteristics of vibro-stone pile composite foundation according to claim 8, characterized in that: The symbol for the foundation bearing capacity is N cf , the N cf The specific calculation formula is: N cf =a1b1mN pf +a2b2(1-m)N sf or N cf =a2N sf [1+m(n-1)], a1 is the correction coefficient of the bearing capacity of the gravel pile, b1 is the ultimate strength of the gravel pile, m is the area replacement rate, N pf is the ultimate bearing capacity of a single gravel pile, a2 is the correction factor for the difference between the natural bearing capacity and the bearing capacity of the soil between the piles, b2 is the ultimate strength of the soil between the piles, and N sf is the ultimate bearing capacity of natural foundation soil, and n is the allowable variation value during construction.

Images