Stiffness characteristic detection method based on ramming amount back analysis and unloading modulus

Abstract

This invention relates to a method for detecting the stiffness characteristics of loading and unloading moduli based on back analysis of settlement, belonging to the field of rigidity testing technology. This invention uses a logarithmic function to fit the variation of the loading modulus with the number of blows. Based on the settlement measured in the experiment, and combined with the basic solution form of structural dynamics, the Boltzmann function is used to back-analyze the variation of both the loading and unloading moduli with the number of blows. This allows for the calculation of the number of blows that meets engineering standards by combining the variation of the loading and unloading moduli with the number of blows. Furthermore, by using an effective compaction index to comprehensively evaluate the settlement attenuation rate, acceleration response, pore water pressure increment, and cumulative settlement convergence, this invention can accurately identify whether the soil at each compaction point has truly reached a dense convergence state, completely avoiding over-compaction or under-compaction problems caused by soil quality differences. This ensures that the reinforcement effect of each compaction point independently meets the engineering design standards, significantly improving the quality pass rate.

Description

Technical Field

[0001] This invention relates to the field of stiffness characteristic testing technology, and in particular to a stiffness characteristic testing method based on the loading and unloading modulus of back-analysis of settlement. Background Technology

[0002] Dynamic compaction, due to its advantages such as good reinforcement effect, low construction cost, and wide applicability, has been widely used in large-area foundation treatment projects such as highways, airport runways, and large industrial plants. In the dynamic compaction construction quality control system, determining the optimal number of blows at a single point (i.e., the stopping standard) is the core link in determining the foundation reinforcement effect. In current engineering practice, the mainstream control logic still revolves around the core paradigm of "stopping the hammer when the preset number of blows is reached." That is, according to the requirements of the "Technical Specification for Foundation Treatment of Buildings" (JGJ 79), the optimal number of blows to meet the design bearing capacity and deformation requirements is first determined through multiple sets of tests in the test compaction area. Then, this number is used as a fixed construction parameter applied to all compaction points in the same geological zone. When the cumulative value of the dynamic compaction machine's counter reaches the preset number, the equipment automatically stops compaction and moves on to the next compaction point.

[0003] However, this open-loop control strategy based on fixed counts has significant technical limitations. First, natural foundation soil has extremely strong heterogeneity and spatial variability. Even within the same test compaction zone, there are objective differences in physical and mechanical properties such as soil density, moisture content, and particle size distribution between different compaction points. Controlling all compaction points with a uniform fixed number of times inevitably leads to some compaction points being "over-compacted" (soil damage and energy waste) while others are "under-compacted" (the reinforcement effect is not up to standard). Summary of the Invention

[0004] This invention overcomes the shortcomings of the prior art and provides a method for detecting stiffness characteristics based on the loading and unloading modulus of the tamping amount in reverse analysis.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of this invention provides a method for detecting stiffness characteristics based on the loading and unloading modulus of back-analysis of compaction amount, comprising the following steps: Dynamic stress data from indoor dynamic compaction tests were collected, and the variation of the loading modulus with the number of blows was fitted using a logarithmic function to obtain the settlement equation for the k-th blow. Combining the settlement equation for the kth blow with the dynamic stress data from the indoor dynamic compaction test, the Boltzmann function was used to back-analyze the variation of the loading modulus and unloading modulus with the number of blows. The number of ground compaction blows required to achieve the engineering design standard is quantitatively evaluated by combining the aforementioned laws governing the changes in reaction loading modulus and unloading modulus with the number of compaction blows. The relevant engineering equipment is controlled based on the current number of foundation compaction blows that meet the engineering design standards.

[0006] Furthermore, in the stiffness characteristic detection method based on the back analysis of settlement and loading modulus, dynamic stress data from indoor dynamic compaction tests are collected, and the variation law of loading modulus with the number of blows is fitted using a logarithmic function to obtain the settlement equation for the kth blow, specifically including: Dynamic stress data from indoor dynamic compaction tests were collected to obtain the displacement-load relationship of the circular rigid bearing plate. The foundation stiffness equation was then constructed based on the displacement-load relationship of the circular rigid bearing plate. Calculate the mean value within the height range of the vibrating soil column, obtain the foundation viscosity coefficient, and solve for the maximum dynamic stress and settlement of the kth blow based on the foundation stiffness equation and the foundation viscosity coefficient. The single-stroke settlement is dimensionless. Based on the maximum dynamic stress and settlement of the k-th blow, a logarithmic function is used to fit the variation of the loading modulus with the number of blows, and the settlement equation of the k-th blow is obtained.

[0007] Furthermore, in the stiffness characteristic detection method based on the back analysis of the settlement and loading / unloading modulus, the settlement equation for the kth blow and the dynamic stress data from the indoor dynamic compaction test are combined with the Boltzmann function to back analyze the variation of the loading modulus and unloading modulus with the number of blows. Specifically, this includes: Combining the settlement equation for the k-th impact with the dynamic stress data from the indoor dynamic compaction test, the Boltzmann function was used to construct a set of equations to express the modulus at the loading stage of the k-th impact under different impact energies in the test. Based on the measured data of the modulus at the k-th impact loading stage under different impact energies in the experiment, three different curves were obtained. Combining the characteristic parameters of the curves, an empirical function of impact energy and related parameters was established. The Boltzmann function is used to characterize the variation of the modulus and unloading modulus in the k-th loading stage, and the stiffness inverse analysis equation based on the settlement is obtained by solving the variation law of the modulus and unloading modulus in the k-th loading stage.

[0008] Furthermore, in the stiffness characteristic detection method based on the back analysis of compaction settlement and loading / unloading modulus, the current foundation compaction count that meets the engineering design standard is quantitatively evaluated by combining the variation law of the loading modulus and unloading modulus with the number of compaction blows. Specifically, this includes: Obtain engineering design standard data information, and use the engineering design standard data information as known variables to solve the stiffness inverse analysis equation of the compaction amount based on the known variables; The number of ground compaction blows required to meet the engineering design standards is obtained by solving the problem, and the number of ground compaction blows required to meet the engineering design standards is output.

[0009] Furthermore, in the stiffness characteristic detection method based on the back analysis of settlement and loading / unloading modulus, the relevant engineering equipment is controlled based on the current number of foundation compaction blows that meet the engineering design standards. Specifically, this includes: Multiple types of sensors are deployed in the target area to collect key parameters for each impact, and the key parameters for each impact are uniformly spatiotemporally aligned. Based on the acceleration response characteristic value and the key parameters of each tamping impact after spatiotemporal alignment, the tamping amount attenuation rate, acceleration response characteristic value and cumulative tamping amount convergence are calculated. The effective compaction index is calculated based on the attenuation rate of compaction, the characteristic value of acceleration response, and the convergence of cumulative compaction, and the effective compaction index sequence of the current compaction point within a preset time is obtained. If the current tamping point contains data below the effective tamping index threshold in the effective tamping index sequence within a preset time, a stop hammer preparation signal is issued in advance. Once the EHI (Electronic Hierarchical Instruction) has met the pre-set criteria for a certain number of consecutive times, it will automatically execute a stop hammer command and record the actual effective number of hammer blows at the current hammer point as the personalized number of times the hammer point meets the criteria.

[0010] A second aspect of the present invention provides a stiffness characteristic detection system based on the loading and unloading modulus of back-analysis of tamping settlement, comprising a memory and a processor. The memory includes a program for a stiffness characteristic detection method based on the loading and unloading modulus of back-analysis of tamping settlement. When the program for the stiffness characteristic detection method based on the loading and unloading modulus of back-analysis of tamping settlement is executed by the processor, it implements the steps of the stiffness characteristic detection method based on the loading and unloading modulus of back-analysis of tamping settlement as described in any one of the present invention.

[0011] A third aspect of the present invention provides a computer-readable storage medium, including a stiffness characteristic detection method program based on the loading and unloading modulus of back-analysis of settlement, wherein when the stiffness characteristic detection method program based on the loading and unloading modulus of back-analysis of settlement is processed and executed, it implements the steps of the stiffness characteristic detection method based on the loading and unloading modulus of back-analysis of settlement as described in any one of the present invention.

[0012] This invention addresses the shortcomings of the prior art and has the following beneficial effects: In this invention, there is a close nonlinear relationship between the settlement of dynamic compaction commonly used in engineering and the loading modulus and unloading modulus. Based on the solution of structural dynamics, this invention uses the measured data of dynamic stress and settlement of multiple dynamic compaction energy levels of the same soil type under the same site conditions to back-analyze the variation law of these two moduli under the condition of progressive compaction. This invention proposes to utilize dynamic stress data from indoor dynamic compaction tests, employing a logarithmic function to fit the variation of the loading modulus with the number of blows. Based on the settlement data from the tests, and combined with the fundamental solution form of structural dynamics, a Boltzmann function is used for back-analysis to derive the laws simultaneously reflecting the variations of the loading and unloading modulus with the number of blows. This allows for the calculation of the number of blows that meets engineering standards by combining the laws reflecting the variations of the loading and unloading modulus with the number of blows. Furthermore, by using an effective compaction index to comprehensively evaluate the settlement attenuation rate, acceleration response, pore water pressure increment, and cumulative settlement convergence, this invention can accurately identify whether the soil at each compaction point has truly reached a dense convergence state. This completely avoids the problems of over-compaction or under-compaction caused by soil quality differences, ensuring that the reinforcement effect of each compaction point independently meets the engineering design standards, and significantly improving the quality qualification rate. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0014] Figure 1 Shown ~ A curve graph; Figure 2 The overall flowchart of the stiffness characteristic detection method based on the loading and unloading modulus of the tamping amount back analysis is shown. Detailed Implementation

[0015] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0016] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0017] The first aspect of this invention provides a method for detecting stiffness characteristics based on the loading and unloading modulus of back-analysis of compaction amount, comprising the following steps: Dynamic stress data from indoor dynamic compaction tests were collected, and the variation of the loading modulus with the number of blows was fitted using a logarithmic function to obtain the settlement equation for the k-th blow. Combining the settlement equation for the kth blow with the dynamic stress data from the indoor dynamic compaction test, the Boltzmann function was used to back-analyze the variation of the loading modulus and unloading modulus with the number of blows. The number of ground compaction blows required to achieve the engineering design standard is quantitatively evaluated by combining the aforementioned laws governing the changes in reaction loading modulus and unloading modulus with the number of compaction blows. The relevant engineering equipment is controlled based on the current number of foundation compaction blows that meet the engineering design standards.

[0018] Furthermore, in the stiffness characteristic detection method based on the back analysis of settlement and loading modulus, dynamic stress data from indoor dynamic compaction tests are collected, and the variation law of loading modulus with the number of blows is fitted using a logarithmic function to obtain the settlement equation for the kth blow, specifically including: Dynamic stress data from indoor dynamic compaction tests were collected to obtain the displacement-load relationship of the circular rigid bearing plate. The foundation stiffness equation was then constructed based on the displacement-load relationship of the circular rigid bearing plate. Calculate the mean value within the height range of the vibrating soil column, obtain the foundation viscosity coefficient, and solve for the maximum dynamic stress and settlement of the kth blow based on the foundation stiffness equation and the foundation viscosity coefficient. The single-stroke settlement is dimensionless. Based on the maximum dynamic stress and settlement of the k-th blow, a logarithmic function is used to fit the variation of the loading modulus with the number of blows, and the settlement equation of the k-th blow is obtained.

[0019] It should be noted that the basic dynamic equations for the loading stage are as follows:

[0020] in This refers to the amount of compaction per click. For the quality of the ram, and These are the foundation loading and unloading stiffness, respectively. and These are the damping coefficients for foundation loading and unloading, respectively. Let u be the acceleration of the hammer (the second derivative of u with respect to time). This represents the first derivative of the single-click tamping depth, and represents the speed of the tamping hammer.

[0021] Foundation stiffness and This can usually be given by the displacement-load relationship of a circular rigid bearing plate:

[0022] Foundation viscosity coefficient and The average value within the height range of the vibrating soil column can be used:

[0023] in The radius of the ram is... The deformation modulus of the foundation. Poisson's ratio of soil The mass density of the soil Let u be the deformation modulus of the foundation. This represents the viscosity coefficient of the u-th foundation.

[0024] The maximum dynamic stress of the k-th impact can be obtained from the above equation. and tamping volume :

[0025] in To generate energy, the first The modulus during the loading phase is The modulus during the unloading stage is . This indicates the stiffness of the first impact unloading.

[0026] The dimensionless settlement of the single-click tamping is expressed by the following formula.

[0027] The formula can then be rewritten as

[0028] According to the above formula, the changes in loading and unloading modulus during the compaction process are mainly reflected in... and Therefore, it is necessary to... and The data is fitted with a function. It represents the square of the compaction amount.

[0029] Furthermore, in the stiffness characteristic detection method based on the back analysis of the settlement and loading / unloading modulus, the settlement equation for the kth blow and the dynamic stress data from the indoor dynamic compaction test are combined with the Boltzmann function to back analyze the variation of the loading modulus and unloading modulus with the number of blows. Specifically, this includes: Combining the settlement equation for the k-th impact with the dynamic stress data from the indoor dynamic compaction test, the Boltzmann function was used to construct a set of equations to express the modulus at the loading stage of the k-th impact under different impact energies in the test. Based on the measured data of the modulus at the k-th impact loading stage under different impact energies in the experiment, three different curves were obtained. Combining the characteristic parameters of the curves, an empirical function of impact energy and related parameters was established. The Boltzmann function is used to characterize the variation of the modulus and unloading modulus in the k-th loading stage, and the stiffness inverse analysis equation based on the settlement is obtained by solving the variation law of the modulus and unloading modulus in the k-th loading stage.

[0030] It should be noted that, With the number of tamping blows The pattern of change is expressed by the following equation.

[0031] Based on the different impact energies (2000kJ, 4000kJ, 6000kJ) in the experiment From the measured data, three different [data] can be obtained. ~ Curves, such as Figure 1 As shown, the formula relates to the impact energy. The relevant parameters are only Therefore, this invention further establishes the impact energy. ~ Empirical relation function:

[0032] in and represents the fitting coefficient.

[0033] As the number of compaction blows increases, the loading modulus of the foundation... and unloading modulus They should gradually converge, that is, the ratio of loading to unloading modulus. As the number of tamping blows increases, the requirements are... And the natural conditions are met. .

[0034] This invention proposes to use the Boltzmann function to characterize This invention proposes using the Boltzmann function to characterize the variation pattern. The pattern of change:

[0035] in The function mainly represents the inflection point of the function's shape, such as... Figure 1 As shown, in practice, the soil stiffness only significantly improves after the number of tamping blows exceeds 2 to 3. The value is relatively fixed; for calibration without experimental data, 3.0 can be used. and With impact energy In particular, this invention patent further proposes to establish impact energy. ~ and ~ Empirical relation function:

[0036] in , and , represents the fitting coefficient.

[0037] Overall fitting effect: The previous text has been obtained and Formal solution, substitution formula The stiffness inverse analysis equation based on the settlement amount can be obtained:

[0038] The measured settlement of the foundation can be used to perform nonlinear parameter regression to obtain the coefficients of each term in the equation. Based on the above derivation, we can obtain... as well as With the number of tamping blows The changes in these factors allow for an accurate quantitative assessment of how many compaction cycles are required for the foundation to meet engineering design standards.

[0039] Furthermore, in the stiffness characteristic detection method based on the back analysis of compaction settlement and loading / unloading modulus, the current foundation compaction count that meets the engineering design standard is quantitatively evaluated by combining the variation law of the loading modulus and unloading modulus with the number of compaction blows. Specifically, this includes: Obtain engineering design standard data information, and use the engineering design standard data information as known variables to solve the stiffness inverse analysis equation of the compaction amount based on the known variables; Engineering design standard data includes soil loading modulus, unloading modulus, and reloading modulus, reflecting the stiffness characteristics of the soil throughout the loading, unloading, and rebound processes.

[0040] The number of ground compaction blows required to meet the engineering design standards is obtained by solving the problem, and the number of ground compaction blows required to meet the engineering design standards is output.

[0041] Furthermore, in the stiffness characteristic detection method based on the back analysis of settlement and loading / unloading modulus, the relevant engineering equipment is controlled based on the current number of foundation compaction blows that meet the engineering design standards. Specifically, this includes: Multiple types of sensors are deployed in the target area to collect key parameters for each impact, and the key parameters for each impact are uniformly spatiotemporally aligned. Based on the acceleration response characteristic value and the key parameters of each tamping impact after spatiotemporal alignment, the tamping amount attenuation rate, acceleration response characteristic value and cumulative tamping amount convergence are calculated. The effective compaction index is calculated based on the attenuation rate of compaction, the characteristic value of acceleration response, and the convergence of cumulative compaction, and the effective compaction index sequence of the current compaction point within a preset time is obtained. If the current tamping point contains data below the effective tamping index threshold in the effective tamping index sequence within a preset time, a stop hammer preparation signal is issued in advance. Once the EHI (Electronic Hierarchical Instruction) has met the pre-set criteria for a certain number of consecutive times, it will automatically execute a stop hammer command and record the actual effective number of hammer blows at the current hammer point as the personalized number of times the hammer point meets the criteria.

[0042] It should be noted that multiple types of sensors (tension sensor, laser rangefinder, accelerometer, pore water pressure sensor, Beidou positioning module) are deployed to collect key parameters of each impact in real time, such as tension data, laser data collected by the laser rangefinder, and acceleration data.

[0043] It should be noted that the settlement per impact decreases with increasing number of impacts. The settlement attenuation rate (SDR) is defined as follows:

[0044] in Let be the settlement amount of the nth tamping blow. Let be the settlement amount of the (n-1)th compaction. When the soil remains below the threshold (e.g., <5%), it indicates that the soil has become compacted.

[0045] Acceleration response eigenvalues Accelerometers mounted on the tamping hammer were used to extract the peak and effective acceleration values ​​for each impact. Studies show a clear theoretical correlation between acceleration characteristic parameters and the effectiveness of foundation reinforcement. When the acceleration response stabilizes, it indicates that the soil stiffness has essentially reached its limit.

[0046] Increment of interstitial water pressure The difference between the maximum pore water pressure of two consecutive compaction blows. When this difference is less than a set threshold, it indicates that the soil no longer produces a significant excess pore water pressure response, that is, it has reached the effective compaction state -1.

[0047] Cumulative compaction convergence The cumulative settlement as a function of the number of tamping blows shows that when the second derivative approaches zero, the compaction effect has converged.

[0048] EHI fusion calculation formula:

[0049] in The weighting coefficients are determined through calibration tests during the trial compaction stage and satisfy the following conditions: .

[0050] It should be noted that this method does not use a preset number of tamping blows as the standard for stopping the hammer, but rather uses whether the actual soil reinforcement effect (EHI) meets the engineering requirements as the criterion, thus achieving personalized construction "tailored to local conditions". Moreover, it integrates multiple physical quantities such as settlement, acceleration, and pore water pressure into a comprehensive evaluation index, overcoming the one-sidedness of single-index criteria.

[0051] In addition, this method also includes: Before construction, an initial three-dimensional geological digital model of the site was established based on borehole data and geophysical exploration results. During construction, real-time data such as the EHI evolution curve of each compaction point, the actual effective number of compaction blows, the compaction settlement sequence, and the inverted soil parameters were transmitted back via the Internet of Things to continuously update the state parameters of the digital twin. The global optimization problem of dynamic compaction construction is modeled as a Markov decision process, and the current state of all compaction points, the current position of the equipment and the state are used to construct a state space in the digital twin. The action space is defined as the next step of moving the equipment to a certain tamping point, continuing to tamp at the current tamping point, stopping the current tamping point, and switching the number of passes. A deep reinforcement learning algorithm is used to conduct virtual training in the digital twin. The intelligent agent is allowed to repeatedly try and fail in a simulation environment to learn the optimal construction strategy. After training, the strategy is deployed to the actual construction and the model is continuously fine-tuned based on the measured data. Based on the strategy output by reinforcement learning, the system generates the optimal walking path and operation sequence for each dynamic compaction machine in real time. When a compaction point requires additional compaction due to abnormal soil conditions, the system automatically adjusts the subsequent path planning.

[0052] It should be noted that the current status of all tamping points in the digital twin includes not under construction / under construction / hammer stopped and EHI value. This method can dynamically adjust the global strategy based on real-time construction feedback, realize a closed-loop evolution of "construction, learning and optimization at the same time", and break the traditional mode of isolated construction of each tamping pass, realize data connection and parameter linkage optimization between passes.

[0053] In addition, this method also includes: An industrial camera is installed on the side or in front of the dynamic compaction machine to acquire a continuous image sequence of the hammer's movement process in real time. A lightweight target detection algorithm (such as YOLO series or MobileNet-SSD) is used to detect and locate the hammer position in each frame of the image, so as to realize the real-time identification and tracking of the hammer target. Based on the positional changes of the ram in a continuous image sequence, the displacement of the ram from the ground to the highest point, the velocity time-series curve of the ram during its descent, the precise moment of ram contact with the ground and the instantaneous velocity at contact, and the rebound height of the ram after contact with the ground are calculated by visual odometry or optical flow method. The displacement of the hammer from the ground to the highest point, the velocity time-series curve of the hammer during its fall, the precise moment of the hammer's contact with the ground and its instantaneous velocity, and the rebound height of the hammer after hitting the ground are mapped to several equivalent indicators of EHI. The equivalent index of the EHI is fused into a visual effective solidification index according to a preset weight value. When the sensor is working normally, the visual data serves as a redundant backup and cross-validation. When the sensor fails due to vibration or dust, it switches to pure vision mode.

[0054] It should be noted that the motion state parameters extracted by vision are transformed into EHI equivalent indicators with clear physical meaning. Moreover, the vision and sensor dual channels run in parallel, serving as backups and verifications for each other, which significantly improves the robustness of the system in harsh construction environments.

[0055] A second aspect of the present invention provides a stiffness characteristic detection system based on the loading and unloading modulus of back-analysis of tamping settlement, comprising a memory and a processor. The memory includes a program for a stiffness characteristic detection method based on the loading and unloading modulus of back-analysis of tamping settlement. When the program for the stiffness characteristic detection method based on the loading and unloading modulus of back-analysis of tamping settlement is executed by the processor, it implements the steps of the stiffness characteristic detection method based on the loading and unloading modulus of back-analysis of tamping settlement as described in any one of the present invention.

[0056] A third aspect of the present invention provides a computer-readable storage medium, including a stiffness characteristic detection method program based on the loading and unloading modulus of back-analysis of settlement, wherein when the stiffness characteristic detection method program based on the loading and unloading modulus of back-analysis of settlement is processed and executed, it implements the steps of the stiffness characteristic detection method based on the loading and unloading modulus of back-analysis of settlement as described in any one of the present invention.

[0057] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0058] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0059] In addition, in the various embodiments of the present invention, each functional unit can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0060] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0061] Alternatively, if the integrated units of this invention are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, RAM, magnetic disks, or optical disks.

[0062] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for detecting stiffness characteristics based on the loading and unloading modulus of tamping settlement in reverse analysis, characterized in that, Includes the following steps: Dynamic stress data from indoor dynamic compaction tests were collected, and the variation of the loading modulus with the number of blows was fitted using a logarithmic function to obtain the settlement equation for the kth blow. Combining the settlement equation for the kth blow with the dynamic stress data from the indoor dynamic compaction test, the Boltzmann function was used to back-analyze the variation of the loading modulus and unloading modulus with the number of blows. The number of ground compaction blows required to achieve the engineering design standard is quantitatively evaluated by combining the aforementioned laws governing the changes in reaction loading modulus and unloading modulus with the number of compaction blows. The relevant engineering equipment is controlled based on the current number of foundation compaction blows that meet the engineering design standards.

2. The stiffness characteristic detection method based on the loading and unloading modulus of the tamping settlement in reverse analysis according to claim 1, characterized in that, Dynamic stress data from indoor dynamic compaction tests were collected. A logarithmic function was used to fit the variation of the loading modulus with the number of blows, yielding the equation for the settlement of the k-th blow. Specifically, this includes: Dynamic stress data from indoor dynamic compaction tests were collected to obtain the displacement-load relationship of the circular rigid bearing plate. The foundation stiffness equation was then constructed based on the displacement-load relationship of the circular rigid bearing plate. Calculate the mean value within the height range of the vibrating soil column, obtain the foundation viscosity coefficient, and solve for the maximum dynamic stress and settlement of the kth blow based on the foundation stiffness equation and the foundation viscosity coefficient. The single-stroke settlement is dimensionless. Based on the maximum dynamic stress and settlement of the k-th blow, a logarithmic function is used to fit the variation of the loading modulus with the number of blows, and the settlement equation of the k-th blow is obtained.

3. The stiffness characteristic detection method based on the loading and unloading modulus of the tamping settlement in reverse analysis according to claim 1, characterized in that, Combining the settlement equation for the k-th blow and the dynamic stress data from indoor dynamic compaction tests, the Boltzmann function is used to back-analyze the variation of the loading modulus and unloading modulus with the number of blows, specifically including: Combining the settlement equation for the k-th impact with the dynamic stress data from the indoor dynamic compaction test, the Boltzmann function was used to construct a set of equations to express the modulus at the loading stage of the k-th impact under different impact energies in the test. Based on the measured data of the modulus at the k-th impact loading stage under different impact energies in the experiment, three different curves were obtained. Combining the characteristic parameters of the curves, an empirical function of impact energy and related parameters was established. The Boltzmann function is used to characterize the variation of the modulus and unloading modulus in the k-th loading stage, and the stiffness inverse analysis equation based on the settlement is obtained by solving the variation law of the modulus and unloading modulus in the k-th loading stage.

4. The stiffness characteristic detection method based on the loading and unloading modulus of the tamping settlement in reverse analysis according to claim 3, characterized in that, The quantitative assessment of the current foundation compaction frequency required to meet engineering design standards is based on the observed changes in the reaction loading modulus and unloading modulus with the number of compaction blows. This includes: Obtain engineering design standard data information, and use the engineering design standard data information as known variables to solve the stiffness inverse analysis equation of the compaction amount based on the known variables; The number of ground compaction blows required to meet the engineering design standards is obtained by solving the problem, and the number of ground compaction blows required to meet the engineering design standards is output.

5. The stiffness characteristic detection method based on the loading and unloading modulus of the tamping settlement in reverse analysis according to claim 1, characterized in that, Based on the current number of foundation compaction blows that meet the engineering design standards, the relevant engineering equipment is controlled, specifically including: Multiple types of sensors are deployed in the target area to collect key parameters for each impact, and the key parameters for each impact are uniformly spatiotemporally aligned. The attenuation rate of compaction, the characteristic value of acceleration response, and the convergence degree of cumulative compaction are calculated based on the characteristic value of acceleration response and the key parameters of each compaction after spatiotemporal alignment. The effective compaction index is calculated based on the attenuation rate of compaction, the characteristic value of acceleration response, and the convergence of cumulative compaction, and the effective compaction index sequence of the current compaction point within a preset time is obtained. If the current tamping point contains data below the effective tamping index threshold in the effective tamping index sequence within a preset time, a stop hammer preparation signal is issued in advance. Once the EHI (Electronic Hierarchical Instruction) has met the pre-set criteria for a certain number of consecutive times, it will automatically execute a stop hammer command and record the actual effective number of hammer blows at the current hammer point as the personalized number of times the hammer point meets the criteria.

6. A stiffness characteristic testing system based on the loading and unloading modulus of back analysis of settlement, characterized in that, The system includes a memory and a processor. The memory includes a program for detecting stiffness characteristics based on the loading and unloading modulus of back-analysis of tamping settlement. When the program for detecting stiffness characteristics based on the loading and unloading modulus of back-analysis of tamping settlement is executed by the processor, it implements the steps of the method for detecting stiffness characteristics based on the loading and unloading modulus of back-analysis of tamping settlement as described in any one of claims 1-5.

7. A computer-readable storage medium, characterized in that, The method includes a stiffness characteristic detection program based on the loading and unloading modulus of the back analysis of the settlement, wherein when the method is processed and executed, the steps of the stiffness characteristic detection method based on the loading and unloading modulus of the back analysis of the settlement are implemented as described in any one of claims 1-5.

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