Soil body compaction degree monitoring method and related device

Abstract

The invention belongs to the field of foundation treatment, and discloses a soil body compaction degree monitoring method and a related device, and the method comprises the steps: collecting a vibration wave signal of a vibration wheel of a road roller operating on the surface of a to-be-detected soil body; carrying out spatial domain filtering and frequency domain filtering processing to obtain a preprocessed vibration wave signal; based on the pre-processed vibration wave signal, combining a pre-constructed elastic wave velocity-density dynamic inversion model to obtain the total density of the to-be-measured soil body; the elastic wave velocity-density dynamic inversion model is deduced according to an expanded Biot fluid saturated porous medium wave equation; the expanded Biot fluid saturated porous medium wave equation is a Biot fluid saturated porous medium wave equation into which unsaturated soil phase constitutive and equivalent soil particle skeleton modulus are introduced; according to the total density of the to-be-measured soil body, the compaction degree of the to-be-measured soil body is obtained through calculation; according to the invention, high-precision monitoring of the compaction degree of the soil body is realized, continuous and real-time monitoring of the construction process of the adaptive road roller can be realized, and the monitoring efficiency and precision are both considered.

Description

Technical Field

[0001] This invention belongs to the field of foundation treatment technology, and relates to soil compaction monitoring technology, and particularly to a soil compaction monitoring method and related device. Background Technology

[0002] Soil compaction monitoring is a key quality control step in the construction of infrastructure such as roads, airport runways, and dams, which directly affects the stability and service life of the engineering structure. Traditional soil compaction monitoring methods mainly include static testing methods such as ring cutter method and sand cone method. However, traditional static testing methods have low testing efficiency and cannot achieve continuous monitoring, making it difficult to meet the real-time quality control requirements of modern construction.

[0003] With the development of sensor technology and signal processing technology, soil compaction monitoring methods based on vibration wave signals are gradually becoming a research hotspot. Currently, existing soil compaction monitoring methods based on vibration wave signals typically involve deploying sensors on the ground surface to collect vibration wave signals during roadbed construction and calculating the soil compaction degree based on the wave velocity-density relationship. However, existing soil compaction monitoring methods based on vibration wave signals generally suffer from large monitoring errors, failing to meet the needs of practical engineering. Specifically, existing methods require the use of coupling agents, resulting in large coupling layer errors that severely affect monitoring accuracy. Furthermore, existing wave velocity-density relationship models have significant flaws, failing to effectively separate the influence of skeletal elasticity and pore fluid, leading to large deviations in monitoring results. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention provides a method and related apparatus for monitoring soil compaction, thereby solving the technical problem that existing soil compaction monitoring methods based on vibration wave signals generally have large monitoring errors and cannot meet the needs of actual engineering.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for monitoring soil compaction, comprising: Vibration wave signals from the vibratory drum of a road roller running on the surface of the soil to be tested are collected; wherein, the vibration wave signals from the vibratory drum of the road roller are received signals from a piezoelectric sensor embedded in the surface of the vibratory drum of the road roller. The vibration wave signal of the vibrating wheel of the road roller is subjected to spatial domain filtering and frequency domain filtering to obtain the pre-processed vibration wave signal; Based on the preprocessed vibration wave signal and combined with the pre-constructed elastic wave velocity-density dynamic inversion model, the total density of the soil to be measured is obtained; wherein, the pre-constructed elastic wave velocity-density dynamic inversion model is derived based on the extended Biot fluid saturated porous media wave equation; the extended Biot fluid saturated porous media wave equation is the Biot fluid saturated porous media wave equation that incorporates the unsaturated soil phase constitutive and equivalent soil particle skeleton modulus. The compaction degree of the soil to be tested is calculated based on the total density of the soil to be tested, and this is used as the monitoring result of the compaction degree of the soil to be tested.

[0006] Furthermore, the piezoelectric sensors are distributed in a spiral grid pattern on the surface of the roller vibrating wheel, and the surface of the piezoelectric sensors is flush with the surface of the roller vibrating wheel.

[0007] Furthermore, the vibration wave signal of the vibratory drum of the road roller can be either an active wave signal or a passive wave signal; The acquisition process of active wave signals is as follows: Select some piezoelectric sensors as active sensors and the remaining piezoelectric sensors as passive sensors; use the active sensors to emit a frequency-sweeping elastic wave of a preset frequency, and the frequency-sweeping elastic wave of the preset frequency propagates through the vibrating wheel of the road roller and the soil to be measured and is received by the passive sensors; collect the received signal of the passive sensors to obtain the active wave signal; The passive wave signal acquisition process is as follows: A piezoelectric sensor is used to receive broadband impact vibration signals generated by the vibrating wheel of a road roller compacting the soil under test, and the received signals of the piezoelectric sensor are collected to obtain passive wave signals.

[0008] Furthermore, the process of performing spatial and frequency domain filtering on the vibration wave signal of the road roller vibratory drum to obtain the preprocessed vibration wave signal includes: A beamforming algorithm based on array topology is used to perform spatial filtering on the vibration wave signal of the road roller vibrating wheel to obtain the spatially filtered vibration wave signal. An adaptive notch filter is used to perform frequency domain filtering on the spatially filtered vibration wave signal to obtain the preprocessed vibration wave signal.

[0009] Furthermore, the extended Biot fluid-saturated porous media wave equation is as follows:

[0010] in, The total density of the soil to be tested; For longitudinal wave velocity; The three-phase modulus of unsaturated soil; Shear modulus; A frequency domain attenuation correction function to introduce a phase transition dissipation mechanism; Equivalent soil particle skeleton modulus; This is the water phase ratio coefficient; Bulk modulus of aqueous phase; This is the air phase ratio coefficient; Bulk modulus of air phase; This refers to the water phase saturation. Porosity; The attenuation coefficient is frequency-dependent. For the distance of propagation.

[0011] Furthermore, the explicit density expression of the pre-constructed elastic wave velocity-density dynamic inversion model is as follows:

[0012] in, The total density of the soil to be tested; For longitudinal wave velocity; A frequency domain attenuation correction function to introduce a phase transition dissipation mechanism; Equivalent soil particle skeleton modulus; Porosity; This refers to the water phase saturation. Bulk modulus of aqueous phase; Bulk modulus of air phase; The transverse wave velocity; Effective stress; Atmospheric pressure; The bulk modulus of the dried skeleton; These are the empirically fitted parameters.

[0013] Furthermore, the engineering simplified model of the pre-constructed elastic wave velocity-density dynamic inversion model is as follows:

[0014] in, The total density of the soil to be tested; These are model constants; The frequency domain attenuation correction function at the center frequency is used to introduce a phase transition dissipation mechanism. The value at; For longitudinal wave velocity; The transverse wave velocity; These are the fitting constants; This refers to the water phase saturation. The center frequency.

[0015] The present invention also provides a soil compaction monitoring system, comprising: The signal acquisition module is used to acquire the vibration wave signal of the vibratory wheel of the road roller running on the surface of the soil to be tested; wherein, the vibration wave signal of the vibratory wheel of the road roller is the received signal of the piezoelectric sensor embedded on the surface of the vibratory wheel of the road roller; The filtering module is used to perform spatial and frequency domain filtering on the vibration wave signal of the road roller vibrating wheel to obtain the pre-processed vibration wave signal. The density calculation module is used to obtain the total density of the soil under test based on the pre-processed vibration wave signal and in combination with the pre-constructed elastic wave velocity-density dynamic inversion model. The pre-constructed elastic wave velocity-density dynamic inversion model is derived based on the extended Biot fluid saturated porous media wave equation. The extended Biot fluid saturated porous media wave equation is the Biot fluid saturated porous media wave equation that incorporates the unsaturated soil phase constitutive and equivalent soil particle skeleton modulus. The compaction calculation module is used to calculate the compaction degree of the soil to be tested based on the total density of the soil to be tested, and to use it as the monitoring result of the compaction degree of the soil to be tested.

[0016] The present invention also provides an electronic device, comprising: A processor is used to execute computer programs; A computer-readable storage medium storing a computer program, which, when executed by the processor, performs the soil compaction monitoring method.

[0017] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the soil compaction monitoring method described above.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The soil compaction monitoring method provided by this invention collects vibration wave signals from the vibratory wheel of a road roller running on the surface of the soil to be tested. The collected vibration wave signals undergo spatial and frequency domain filtering to effectively filter out various interference signals and improve signal quality in the construction environment, ensuring that the vibration wave signals used for calculation and analysis more closely match the actual vibration characteristics of the soil. Based on the extended Biot fluid saturated porous medium wave equation, which incorporates the constitutive model of unsaturated soil phases and the equivalent soil particle skeleton modulus, an elastic wave velocity-density dynamic inversion model is derived and constructed. This model effectively separates the influence of soil skeleton elasticity and pore fluid on vibration wave propagation, accurately describing the complex mechanical properties of unsaturated soil, and enabling the method to be based on… The model inverts the total soil density to a value closer to the actual value, ultimately significantly reducing compaction monitoring errors and achieving high-precision monitoring of soil compaction. Adapted to the construction process of road rollers, it enables continuous, real-time monitoring, balancing monitoring efficiency and accuracy, and fully meeting the real-time quality control requirements of modern construction. Specifically, the design of directly embedding piezoelectric sensors on the surface of the road roller's vibrating drum allows the sensors to directly collect vibration wave signals generated by the contact between the vibrating drum and the soil being tested. This eliminates the need for additional surface sensors and the use of coupling agents, fundamentally eliminating coupling errors caused by the presence of a coupling layer. This significantly improves the accuracy of vibration wave signal acquisition, laying a data foundation for improved monitoring precision.

[0019] The soil compaction monitoring system, electronic device, and computer-readable storage medium provided by this invention possess all the advantages of the aforementioned soil compaction monitoring methods. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A flowchart of the soil compaction monitoring method provided in Example 1; Figure 2 This is a structural block diagram of the soil compaction monitoring system provided in Example 2; Figure 3 This is a structural block diagram of the electronic device provided in Example 3. Detailed Implementation

[0022] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] This invention provides a method for monitoring soil compaction, comprising the following steps: Step 100: Collect the vibration wave signal of the vibratory wheel of the road roller running on the surface of the soil to be tested; wherein, the vibration wave signal of the vibratory wheel of the road roller is the received signal of the piezoelectric sensor embedded on the surface of the vibratory wheel of the road roller.

[0024] Step 200: Perform spatial domain filtering and frequency domain filtering on the vibration wave signal of the road roller vibrating wheel to obtain the pre-processed vibration wave signal.

[0025] Step 300: Based on the preprocessed vibration wave signal and combined with the pre-constructed elastic wave velocity-density dynamic inversion model, the total density of the soil to be tested is obtained as the monitoring result of the compaction degree of the soil to be tested; wherein, the pre-constructed elastic wave velocity-density dynamic inversion model is derived based on the extended Biot fluid saturated porous media wave equation; the extended Biot fluid saturated porous media wave equation is the Biot fluid saturated porous media wave equation that incorporates the constitutive model of unsaturated soil phase and the equivalent soil particle skeleton modulus.

[0026] Step 400: Calculate the compaction degree of the soil to be tested based on the total density of the soil to be tested, and use it as the monitoring result of the compaction degree of the soil to be tested.

[0027] In the above embodiments, by collecting vibration wave signals from piezoelectric sensors on the surface of the road roller vibrating wheel and obtaining preprocessed signals through spatial and frequency domain filtering, signal interference is effectively reduced and data quality is improved. Based on the elastic wave velocity-density dynamic inversion model derived from the extended Biot fluid saturated porous media wave equation, the influence of skeleton elasticity and pore fluid is effectively separated by introducing unsaturated soil phase constitutive and equivalent soil particle skeleton modulus into the inversion model, overcoming the defects of traditional models. This invention can significantly reduce monitoring errors, meet the needs of real-time and accurate monitoring of soil compaction in actual engineering, and provide reliable assurance for quality control of infrastructure construction such as roads and airport runways.

[0028] The following specific embodiments further explain the soil compaction monitoring method provided by the present invention: Example 1 As attached Figure 1As shown in Example 1, this method for monitoring soil compaction includes the following steps: Step 1: Collect the vibration wave signal of the vibratory drum of the road roller running on the surface of the soil to be tested; wherein, the vibration wave signal of the road roller vibratory drum is the received signal of the piezoelectric sensor embedded in the vibratory surface of the road roller. Specifically, the vibration wave signal of the road roller vibratory drum is an active wave signal or a passive wave signal.

[0029] It is worth noting that in the process of collecting vibration wave signals from the vibratory wheel of a road roller running on the surface of the soil to be tested, the steel wheel of the road roller vibratory wheel is used as an elastic waveguide carrier and the soil to be tested is used as the wave propagation medium to eliminate the coupling error of traditional surface-deployed sensors.

[0030] When the vibration wave signal of the road roller's vibratory drum is an active wave signal, the acquisition process is as follows: Select some piezoelectric sensors as active sensors and the remaining piezoelectric sensors as passive sensors; use the active sensors to emit a frequency-sweeping elastic wave of a preset frequency, and the frequency-sweeping elastic wave of the preset frequency propagates through the vibrating wheel of the road roller and the soil to be measured and is received by the passive sensors; collect the received signal of the passive sensors to obtain the active wave signal.

[0031] The principle of active wave signal acquisition is as follows: A portion of the piezoelectric sensors deployed on the edge of the vibratory roller's drum are selected as active sensors, while the remaining piezoelectric sensors are used as passive sensors. A 10-30kHz swept-frequency elastic wave (SH wave) is emitted by the selected active piezoelectric sensors. This wave propagates circumferentially through the steel wheel of the vibratory roller, reaches the interface of the soil to be tested, and couples into the soil layer. It is then received by the passive piezoelectric sensors located diagonally on the vibratory roller's drum. The high wave velocity (approximately 5000 m / s) of the steel wheel is utilized to compress the wave propagation time, focusing 90% of the energy into the shallow soil layer within a 0-30cm range. The active wave signal is obtained by collecting the wave signals received by the passive piezoelectric sensors and serves as the vibration wave signal of the vibratory roller's drum.

[0032] When the vibration wave signal of the road roller's vibratory drum is a passive wave signal, the acquisition process is as follows: A piezoelectric sensor is used to receive broadband impact vibration signals generated by the vibrating wheel of a road roller compacting the soil under test, and the received signals of the piezoelectric sensor are collected to obtain passive wave signals.

[0033] The principle of passive wave signal acquisition is as follows: The steel wheel of a road roller is used to compact the soil, generating a broadband impact vibration wave of 0.5-5kHz. The broadband impact vibration wave is transmitted to a piezoelectric sensor through the steel wheel of the road roller. The wave signal received by the piezoelectric sensor is extracted by a cross-correlation algorithm to obtain a passive wave signal, which is used as the vibration wave signal of the road roller's vibratory wheel.

[0034] It should be noted that the piezoelectric sensors are distributed in a spiral grid pattern on the surface of the roller vibratory wheel, and the surface of the piezoelectric sensors is flush with the surface of the roller vibratory wheel. Specifically, several sets of embedding slots are opened on the steel wheel surface of the roller vibratory wheel, and these sets of embedding slots are evenly distributed along the axial direction of the roller vibratory wheel. Each set of embedding slots includes several embedding grooves, which are evenly distributed on the same circumference of the roller vibratory wheel. Among them, the embedding grooves in two adjacent sets of embedding slots are spirally distributed. A piezoelectric sensor is installed in each embedding groove, and the surface of the piezoelectric sensor is flush with the surface of the roller vibratory wheel. This avoids wear from rolling and achieves zero-distance contact between the piezoelectric sensor and the rolling surface of the soil to be measured, thereby eliminating the coupling layer error that exists when sensors are deployed on the ground surface in traditional technologies.

[0035] In this embodiment 1, each piezoelectric sensor is provided with a metal shield on its outer side, and the space between the metal shield and the piezoelectric sensor is filled with silicone material; wherein, the compressive strength of the metal shield is greater than 200MPa, and the temperature resistance of the silicone material is 25℃; preferably, the piezoelectric sensor is a piezoelectric ceramic sensor, the surface of the piezoelectric ceramic sensor is provided with a nickel-plated anti-corrosion layer, and the piezoelectric ceramic sensor has a lifespan of greater than 500h under the impact load of a 30-ton road roller.

[0036] Step 2: Perform spatial domain filtering and frequency domain filtering on the vibration wave signal of the road roller vibratory wheel to obtain the pre-processed vibration wave signal.

[0037] Specifically, the process is as follows: Step 21: Using a beamforming algorithm based on array topology, the vibration wave signal of the road roller vibrating drum is spatially filtered to obtain a spatially filtered vibration wave signal. Specifically, the vibration wave signal of the road roller vibrating drum is weighted and summed to enhance the vibration wave signal from a specific direction while suppressing interference signals and noise from other directions. In practice, firstly, the weighting coefficients of each piezoelectric sensor signal are calculated based on the incident direction of the desired signal and the distribution parameters of the piezoelectric sensor. Then, the vibration wave signals collected by each piezoelectric sensor are weighted according to the calculated weighting coefficients. Finally, the weighted vibration wave signals are summed to obtain the spatially filtered vibration wave signal. Through spatial filtering, interference from non-desired directions in space can be effectively removed, highlighting the signal generated by the vibration of the road roller vibrating drum itself, improving the signal-to-noise ratio, and providing a cleaner signal for subsequent frequency domain filtering.

[0038] Step 22: An adaptive notch filter is used to perform frequency domain filtering on the spatially filtered vibration wave signal to obtain the preprocessed vibration wave signal. The adaptive notch filter, as a filter that can automatically adjust its parameters to adapt to changes in signal and noise characteristics, mainly suppresses the fundamental frequency of the road roller engine vibration, such as the 20-30Hz vibration signal, when processing the spatially filtered vibration wave signal. During the operation of the road roller's vibrating wheel, there may be some fixed-frequency interference sources, such as the periodic vibration generated by the operation of surrounding mechanical equipment. The interference sources will form specific frequency components in the spectrum of the vibration wave signal.

[0039] Specifically, the adaptive notch filter adjusts its notch frequency and bandwidth by monitoring the spectral characteristics of the input signal in real time, aligning its notch center frequency with the interference frequency. When the signal passes through the adaptive notch filter, interference components within the notch frequency range are significantly attenuated, while the main frequency components of the vibration signal from the road roller's vibrating drum are well preserved. After frequency domain filtering, the pre-processed vibration wave signal is finally obtained. The pre-processed vibration wave signal is purer and more conducive to subsequent analysis and judgment of the road roller's vibrating drum's operating status.

[0040] Optionally, a temperature sensor is pre-built into the piezoelectric sensor. After frequency domain filtering, the temperature data collected by the built-in temperature sensor is used to correct the pre-processed vibration wave signal, so as to correct the response characteristics of the piezoelectric sensor in real time, thereby reducing the temperature drift coefficient from 0.1% / ℃ to 0.01% / ℃ and realizing temperature drift compensation.

[0041] Step 3: Based on the extended Biot fluid-saturated porous media wave equation, a pre-constructed elastic wave velocity-density dynamic inversion model is derived. The extended Biot fluid-saturated porous media wave equation is the one incorporating unsaturated soil phase constitutive modulus and equivalent soil particle skeleton modulus.

[0042] Specifically, the extended Biot fluid-saturated porous media wave equation is as follows:

[0043] in, The total density of the soil to be tested is the mixed density under saturated / unsaturated conditions. P-wave velocity is used to reflect the coupling effect between soil stiffness and inertia. It represents the three-phase modulus of unsaturated soil, namely the modulus of the soil skeleton, water phase, and air phase; It is the shear modulus, which is related to the stiffness of the soil skeleton and is not directly affected by the degree of saturation. A frequency domain attenuation correction function to introduce a phase transition dissipation mechanism; It is the equivalent soil particle skeleton modulus, used to reflect the elastic response of the solid particle skeleton alone; The water phase proportion coefficient is used to reflect the geometric characteristics of the water phase distribution in unsaturated soil, in order to quantify the contribution of water phase to the overall modulus, and is controlled by pore structure and saturation. This is the bulk modulus of the aqueous phase, used to reflect the compressibility of the aqueous phase; It is the air phase proportion coefficient, used to reflect the geometric characteristics of air phase distribution in unsaturated soil; This is the bulk modulus of the air phase, which is neglected in traditional Biot theory, but is explicitly introduced in this embodiment 1; This refers to the water phase saturation, which is the proportion of water volume to pore volume. Porosity is the ratio of pore volume to total volume. The attenuation coefficient is frequency-dependent. For the distance of propagation.

[0044] It should be noted that traditional wave velocity-density relationship models are described by nonlinear partial differential equations (such as the GHF-Gardner equation) for typical nonlinear wave propagation. However, the GHF-Gardner equation usually has two significant drawbacks: First, the equation does not separate the effects of skeletal elasticity and pore fluid, essentially ignoring the multiphase nature of the soil. When the water content of the soil to be tested changes by 10%, the density inversion error can be greater than 15%. Second, the equation simplifies the constitutive relation by treating Poisson's ratio and modulus as constants. However, in actual soil compaction, the Poisson's ratio will vary from 0.2 to 0.4 due to frequent disturbances.

[0045] In this embodiment 1, by introducing the unsaturated soil phase constitutive model and the equivalent soil particle skeleton modulus into the Biot fluid-saturated porous media wave equation, a four-dimensional parameter mapping is established, resulting in the extended Biot fluid-saturated porous media wave equation; wherein... As the fundamental waveguide equation; An extended definition of saturated bulk modulus; Defined as the proportion coefficient of a phase; As a frequency-domain attenuation correction term, the frequency-domain dependent attenuation coefficient is... It encompasses phase transition dissipation and four-dimensional parameter mapping; phase transition dissipation refers to energy loss caused by dynamic changes in the gas-liquid interface in unsaturated soil; four-dimensional parameter mapping introduces multi-field coupling effects including temperature, chemical formula, etc., i.e., frequency-domain dependent attenuation coefficients. In practice, it is expanded to .

[0046] Frequency domain dependent attenuation coefficient It includes a skeleton scattering term, a fluid viscous dissipation term, and a capillary effect term; among which, the skeleton scattering term is used to represent the elastic scattering loss of the soil particle skeleton; the fluid viscous dissipation term is used to describe the viscous dissipation of the fluid; the capillary effect term depends on the sum of the water phase saturation and the power of the frequency, and is used to represent the energy dissipation at the water-air interface caused by capillary forces in unsaturated soil.

[0047] Specifically, frequency-domain dependent attenuation coefficient The physical mechanism is as follows:

[0048] in, The scattering coefficient is the skeleton scattering coefficient. Angular frequency; For fluid density; Pore ​​geometry factor related to soil particle geometry; , and All are empirical constants; This represents the fluid viscosity.

[0049] Frequency domain dependent attenuation coefficient The overall attenuation coefficient increases with frequency, especially in the high-frequency domain; frequency-dependent attenuation coefficient The capillary effect term in the equation dominates at low saturation; therefore, a frequency-dependent attenuation coefficient is introduced. The microscopic mechanism (capillary effect) of unsaturated soil is incorporated into the macroscopic fluctuation model.

[0050] In this embodiment 1, the pre-constructed elastic wave velocity-density dynamic inversion model includes an explicit density expression and an engineering simplified model. Specifically, by explicitly reconstructing the extended Biot fluid saturated porous medium wave equation and introducing an equivalent soil particle skeleton modulus to replace the modulus constant of the traditional model, the explicit density expression of the pre-constructed elastic wave velocity-density dynamic inversion model can be obtained, which is used to invert the soil density.

[0051] Specifically, the explicit density expression of the pre-constructed elastic wave velocity-density dynamic inversion model is as follows:

[0052] in, The total density of the soil to be tested; For longitudinal wave velocity; A frequency domain attenuation correction function to introduce a phase transition dissipation mechanism; Equivalent soil particle skeleton modulus; Porosity; This refers to the water phase saturation. Bulk modulus of aqueous phase; Bulk modulus of air phase; The transverse wave velocity; Effective stress; Atmospheric pressure; The bulk modulus of the dried skeleton; These are the empirically fitted parameters.

[0053] It should be noted that the explicit density expression of the pre-constructed elastic wave velocity-density dynamic inversion model is derived from the extended Biot fluid saturated porous media wave equation, which integrates the unsaturated soil effect and frequency attenuation; the shear modulus is also included. Substituting it in causes the expression to show the total density of the soil being tested. The recursive dependency requires fixing the total density of the soil to be tested. The initial value is solved iteratively, which can be simplified in practice.

[0054] By simplifying the explicit density expression of the pre-constructed elastic wave velocity-density dynamic inversion model, a simplified engineering model can be obtained; the simplification approach includes: (1) ignoring the iteration term: assuming that the explicit density expression contains... (2) Using wave speed ratio Instead of separate P-wave velocity and transverse wave velocity (3) Simplify the frequency domain: By introducing a frequency domain attenuation correction function based on the phase transition dissipation mechanism at the center frequency Calculation at the point; (4) Introduce empirical terms Saturation treatment is performed; when the water phase saturation is... When it approaches 0.25, the empirical term Approaching 1.

[0055] The engineering simplified model of the pre-constructed elastic wave velocity-density dynamic inversion model is as follows:

[0056] in, The total density of the soil to be tested; These are model constants; The frequency domain attenuation correction function at the center frequency is used to introduce a phase transition dissipation mechanism. The value at; For longitudinal wave velocity; The transverse wave velocity; These are the fitting constants; This refers to the water phase saturation. The center frequency.

[0057] It should be noted that when using the explicit density expression of the pre-constructed elastic wave velocity-density dynamic inversion model to invert soil density, the inversion logic is as follows: given the longitudinal wave velocity... transverse wave velocity Frequency domain attenuation correction function incorporating phase transition dissipation mechanism and porosity The total density of the soil to be tested can be obtained. The solution is performed; when inverting soil density using the engineering simplification model of the pre-constructed elastic wave velocity-density dynamic inversion model, the inversion logic is as follows: given the longitudinal wave velocity... transverse wave velocity The frequency domain attenuation correction function that introduces a phase transition dissipation mechanism at the center frequency value at and water phase saturation The total density of the soil to be tested can be obtained. The solution is suitable for rapid inversion at construction sites.

[0058] Step 4: Based on the preprocessed vibration wave signal and combined with the pre-constructed elastic wave velocity-density dynamic inversion model, calculate the total density of the soil to be tested. Specifically, substitute the preprocessed vibration signal into the pre-constructed elastic wave velocity-density dynamic inversion model to calculate the total density of the soil to be tested.

[0059] Step 5: Calculate the compaction degree of the soil to be tested based on its total density, and use this as the monitoring result of the soil compaction degree. The calculation process for the compaction degree of the soil to be tested is as follows:

[0060] in, The compaction degree of the soil to be tested; This represents the maximum dry density measured in the experiment.

[0061] Taking the compaction monitoring process of a certain unsaturated sand as an example, the soil compaction monitoring method described in Example 1 above is illustrated. In this example, the piezoelectric sensors on the vibrating wheel of the road roller are arranged in a spiral grid pattern with 6 circles along the circumference of the steel wheel, and 8 piezoelectric sensors in each axial circle, for a total of 48 piezoelectric sensors. The spacing is distributed at 50mm×50mm to cover the full width of the steel wheel and achieve 100% wave field coverage of the compaction zone.

[0062] In this example, the equivalent soil particle skeleton modulus Take 1 GPa, water phase bulk modulus The air phase bulk modulus is 2.2 GPa. The pressure is 0.01 GPa; porosity The water phase saturation is 0.3. It is 0.6; P-wave velocity The transverse wave velocity is 1500 m / s. 500 m / s; frequency-dependent attenuation coefficient The value was 0.1; the total density of the soil tested was 2000 kg / m³. 3 .

[0063] Calculations show that the three-phase modulus of unsaturated soil is... and the total density of the soil to be tested The calculation results are as follows:

[0064]

[0065] Therefore, the total density of the soil to be tested calculated using the above soil compaction monitoring method is basically consistent with the total density of the soil to be tested obtained by experimental testing. Thus, the monitoring results of soil compaction will also be basically consistent with the actual results.

[0066] The soil compaction monitoring method described in Embodiment 1 acquires vibration wave signals by directly embedding a piezoelectric sensor on the surface of the vibrating wheel of a road roller, eliminating the need for additional coupling agent. This eliminates contact errors caused by the coupling layer in traditional surface sensor deployment, ensuring that the vibration wave signal directly and accurately reflects the vibration response of the soil under test. This provides high-precision raw data support for subsequent signal processing and parameter calculation. Combined spatial and frequency domain filtering of the vibration wave signal effectively removes interference signals from the construction environment, reducing the impact of noise on subsequent wave velocity calculations. The method is based on the introduction of unsaturated soil phase constitutive model and equivalent soil particle skeleton modulus. Extending Biot's fluid-saturated porous media wave equation, a dynamic inversion model of elastic wave velocity-density is derived and constructed to accurately separate the respective influences of soil skeleton elasticity and pore fluid. This model better reflects the unsaturated state and complex structural characteristics of soil in actual engineering, making the correspondence between elastic wave velocity and total soil density more scientific and accurate. Consequently, the error of the compaction result obtained through total density calculation is significantly reduced, meeting the high-precision requirements of compaction monitoring in actual engineering. At the same time, relying on sensors mounted on road rollers to achieve real-time acquisition and processing of vibration wave signals, it takes into account both the continuity and efficiency of monitoring, adapting to the real-time quality control requirements of modern construction.

[0067] Example 2 As attached Figure 2 As shown in the figure, this embodiment 2 provides a soil compaction monitoring system, including a signal acquisition module, a filtering module, a density calculation module and a compaction calculation module.

[0068] The signal acquisition module is used to acquire the vibration wave signal of the vibratory wheel of the road roller running on the surface of the soil to be tested; wherein, the vibration wave signal of the vibratory wheel of the road roller is the received signal of the piezoelectric sensor embedded on the surface of the vibratory wheel of the road roller.

[0069] The filtering module is used to perform spatial and frequency domain filtering on the vibration wave signal of the road roller's vibrating wheel to obtain the pre-processed vibration wave signal.

[0070] The density calculation module is used to obtain the total density of the soil under test based on the preprocessed vibration wave signal and in combination with the pre-constructed elastic wave velocity-density dynamic inversion model.

[0071] The compaction calculation module is used to calculate the compaction degree of the soil to be tested based on the total density of the soil to be tested, and to use it as the monitoring result of the compaction degree of the soil to be tested.

[0072] In this embodiment 2, the pre-constructed elastic wave velocity-density dynamic inversion model is derived based on the extended Biot fluid saturated porous media wave equation; the extended Biot fluid saturated porous media wave equation is the Biot fluid saturated porous media wave equation that incorporates the constitutive model of unsaturated soil phase and the equivalent soil particle skeleton modulus.

[0073] Optionally, the explicit density expression of the pre-built elastic wave velocity-density dynamic inversion model is as follows:

[0074] in, The total density of the soil to be tested; For longitudinal wave velocity; A frequency domain attenuation correction function to introduce a phase transition dissipation mechanism; Equivalent soil particle skeleton modulus; Porosity; This refers to the water phase saturation. Bulk modulus of aqueous phase; Bulk modulus of air phase; The transverse wave velocity; Effective stress; Atmospheric pressure; The bulk modulus of the dried skeleton; These are the empirically fitted parameters.

[0075] The engineering simplified model of the pre-constructed elastic wave velocity-density dynamic inversion model is as follows:

[0076] in, The total density of the soil to be tested; These are model constants; The frequency domain attenuation correction function at the center frequency is used to introduce a phase transition dissipation mechanism. The value at; For longitudinal wave velocity; The transverse wave velocity; These are the fitting constants; This refers to the water phase saturation. The center frequency.

[0077] Example 3 As attached Figure 3 As shown, this embodiment 3 provides an electronic device, including: a memory for storing a computer program; a processor for executing the computer program to implement the steps of the soil compaction monitoring method; or, the processor executing the computer program to implement the functions of each module in the above-mentioned soil compaction monitoring system.

[0078] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a preset function, the instruction segments describing the execution process of the computer program in the electronic device.

[0079] The electronic device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The electronic device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the above are examples of electronic devices and do not constitute a limitation on the electronic device. It may include more components than described above, or combine certain components, or different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0080] The processor can be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits, off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor, or any conventional processor, etc. The processor is the control center of the electronic device, connecting various parts of the entire electronic device through various interfaces and lines.

[0081] The memory can be used to store the computer program and / or module, and the processor implements various functions of the electronic device by running or executing the computer program and / or module stored in the memory, and by calling the data stored in the memory.

[0082] The memory may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function (such as sound playback, image playback, etc.). The data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). Furthermore, the memory may include high-speed random access memory and non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart memory cards, secure digital cards, flash memory cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0083] Example 4 This embodiment 4 also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the soil compaction monitoring method described above.

[0084] If the modules / units integrated in the soil compaction monitoring system are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0085] Based on this understanding, the present invention can implement all or part of the processes in the above-described soil compaction monitoring method, or it can be accomplished by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the above-described soil compaction monitoring method. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or a preset intermediate form, etc.

[0086] The computer-readable storage medium may include: any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0087] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A method for monitoring soil compaction, characterized in that, include: Vibration wave signals from the vibratory drum of a road roller running on the surface of the soil to be tested are collected; wherein, the vibration wave signals from the vibratory drum of the road roller are received signals from a piezoelectric sensor embedded in the surface of the vibratory drum of the road roller. The vibration wave signal of the vibrating wheel of the road roller is subjected to spatial domain filtering and frequency domain filtering to obtain the pre-processed vibration wave signal; Based on the preprocessed vibration wave signal and combined with the pre-constructed elastic wave velocity-density dynamic inversion model, the total density of the soil to be measured is obtained; wherein, the pre-constructed elastic wave velocity-density dynamic inversion model is derived based on the extended Biot fluid saturated porous media wave equation; the extended Biot fluid saturated porous media wave equation is the Biot fluid saturated porous media wave equation that incorporates the unsaturated soil phase constitutive and equivalent soil particle skeleton modulus. The compaction degree of the soil to be tested is calculated based on the total density of the soil to be tested, and this is used as the monitoring result of the compaction degree of the soil to be tested.

2. The method for monitoring soil compaction degree according to claim 1, characterized in that, The piezoelectric sensors are distributed in a spiral grid pattern on the surface of the roller vibrating wheel, and the surface of the piezoelectric sensors is flush with the surface of the roller vibrating wheel.

3. The method for monitoring soil compaction according to claim 1, characterized in that, The vibration wave signal of the vibratory drum of the road roller can be an active wave signal or a passive wave signal; The acquisition process of active wave signals is as follows: Select some piezoelectric sensors as active sensors and the remaining piezoelectric sensors as passive sensors; use the active sensors to emit a frequency-sweeping elastic wave of a preset frequency, and the frequency-sweeping elastic wave of the preset frequency propagates through the vibrating wheel of the road roller and the soil to be measured and is received by the passive sensors; collect the received signal of the passive sensors to obtain the active wave signal; The passive wave signal acquisition process is as follows: A piezoelectric sensor is used to receive broadband impact vibration signals generated by the vibrating wheel of a road roller compacting the soil under test, and the received signals of the piezoelectric sensor are collected to obtain passive wave signals.

4. The method for monitoring soil compaction degree according to claim 1, characterized in that, The process of performing spatial and frequency domain filtering on the vibration wave signal of a road roller vibratory drum to obtain a preprocessed vibration wave signal includes: A beamforming algorithm based on array topology is used to perform spatial filtering on the vibration wave signal of the road roller vibrating wheel to obtain the spatially filtered vibration wave signal. An adaptive notch filter is used to perform frequency domain filtering on the spatially filtered vibration wave signal to obtain the preprocessed vibration wave signal.

5. The method for monitoring soil compaction degree according to claim 1, characterized in that, The extended Biot fluid-saturated porous media wave equation is as follows: in, The total density of the soil to be tested; For longitudinal wave velocity; The three-phase modulus of unsaturated soil; Shear modulus; A frequency domain attenuation correction function to introduce a phase transition dissipation mechanism; Equivalent soil particle skeleton modulus; This is the water phase ratio coefficient; Bulk modulus of aqueous phase; This is the air phase ratio coefficient; Bulk modulus of air phase; This refers to the water phase saturation. Porosity; The attenuation coefficient is frequency-dependent. For the distance of propagation.

6. The method for monitoring soil compaction degree according to claim 1, characterized in that, The explicit density expression of the pre-constructed elastic wave velocity-density dynamic inversion model is as follows: in, The total density of the soil to be tested; For longitudinal wave velocity; A frequency domain attenuation correction function to introduce a phase transition dissipation mechanism; Equivalent soil particle skeleton modulus; Porosity; This refers to the water phase saturation. Bulk modulus of aqueous phase; Bulk modulus of air phase; The transverse wave velocity; Effective stress; Atmospheric pressure; The bulk modulus of the dried skeleton; These are the empirically fitted parameters.

7. The method for monitoring soil compaction degree according to claim 1, characterized in that, The engineering simplified model of the pre-constructed elastic wave velocity-density dynamic inversion model is as follows: in, The total density of the soil to be tested; These are model constants; The frequency domain attenuation correction function at the center frequency is used to introduce a phase transition dissipation mechanism. The value at; For longitudinal wave velocity; The transverse wave velocity; These are the fitting constants; This refers to the water phase saturation. The center frequency.

8. A soil compaction monitoring system, characterized in that, include: The signal acquisition module is used to acquire the vibration wave signal of the vibratory wheel of the road roller running on the surface of the soil to be tested; wherein, the vibration wave signal of the vibratory wheel of the road roller is the received signal of the piezoelectric sensor embedded on the surface of the vibratory wheel of the road roller; The filtering module is used to perform spatial and frequency domain filtering on the vibration wave signal of the road roller vibrating wheel to obtain the pre-processed vibration wave signal. The density calculation module is used to obtain the total density of the soil under test based on the pre-processed vibration wave signal and in combination with the pre-constructed elastic wave velocity-density dynamic inversion model. The pre-constructed elastic wave velocity-density dynamic inversion model is derived based on the extended Biot fluid saturated porous media wave equation. The extended Biot fluid saturated porous media wave equation is the Biot fluid saturated porous media wave equation that incorporates the unsaturated soil phase constitutive and equivalent soil particle skeleton modulus. The compaction calculation module is used to calculate the compaction degree of the soil to be tested based on the total density of the soil to be tested, and to use it as the monitoring result of the compaction degree of the soil to be tested.

9. An electronic device, characterized in that, include: A processor is used to execute computer programs; A computer-readable storage medium storing a computer program, which, when executed by the processor, performs the soil compaction monitoring method as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the soil compaction monitoring method as described in any one of claims 1-7.

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