A method, system, equipment and medium for rapid nondestructive testing of cement pavement

Abstract

The present invention relates to a method, system, equipment and medium for rapid nondestructive testing of cement pavement, and belongs to the technical field of pavement testing. The method comprises: receiving a source pulse signal through a receiver placed vertically on the measured pavement, performing secondary measurement of the inverted source according to the arrangement mode of the source and the receiver, and obtaining a field measured signal after signal averaging processing of the measured source pulse signal; constructing a dispersion curve according to the field measured signal, and analyzing the elastic modulus information of different depths under the pavement according to the dispersion curve inversion; combining the pavement structure parameters and the elastic modulus information, calculating the damage degree and position of the pavement through a nondestructive testing model, and finally outputting a cement pavement test report according to the calculated damage degree and position. The time and labor cost required for traditional testing methods are greatly reduced, and the testing efficiency and accuracy are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of road surface detection, and in particular relates to a method, system, equipment and medium for rapid nondestructive detection of cement road surfaces. Background Art

[0002] In the highway system, many cement concrete roads are gradually approaching the end of their design life or facing the need to be upgraded to asphalt pavement. Due to the lack of a quick, economical and accurate method to evaluate the health and performance of these cement pavements, regular and effective maintenance inspections have become quite challenging. In terms of measuring the modulus of existing cement pavements, compared with traditional on-site coring destructive testing, non-destructive testing technology stands out for its high efficiency, low cost and environmental protection advantages. This technology can evaluate material properties without damaging the pavement and ensure the integrity of the road system, so it is gradually becoming the preferred method for pavement modulus testing.

[0003] Traditionally, the Falling Weight Deflectometer (FWD) method is used as the standard technology for measuring the Young's modulus of pavement, base and subgrade. However, the calculation process of the FWD method depends on some unknown parameters, such as the thickness of each structural layer, and is less sensitive to the change of the modulus of the surface layer. The new non-destructive testing technology is based on the SASW method (Spectral Analysis of Surface Waves), which is known for its novelty, rapidity, accuracy and reliability. Its core principle is to use two receivers to capture the signal generated by ground vibration and calculate the shear wave velocity that varies with depth based on the dispersion characteristics of the surface wave, thereby inferring the shear wave velocity of each layer in the layered structure. By analyzing the signal differences generated when the surface wave propagates in the stratum, the physical properties of the stratum can be determined. Since the advent of the SASW method, its research and application fields have expanded rapidly, and many valuable discoveries and successful cases have been made in the evaluation of asphalt pavements. Despite this, domestic research on the use of the SASW method to evaluate the modulus of cement pavements is still relatively limited. The SASW method has high requirements for signal quality, which means that very precise and high-quality data acquisition is required during the test process, otherwise the accuracy of the results may be affected, and the test and data processing efficiency is low, especially in the inversion analysis process, which requires complex iterative algorithms, which increases the time cost of the test. When performing the inversion analysis, it is very sensitive to the initial value setting of the elastic modulus profile. If the initial value is set improperly, the inversion result may be inaccurate; the SASW test results show a large variability, which indicates that the defects of the pavement structure layer cannot be identified by only a few test points. This variability may lead to inconsistency in the quality of the pavement structure, which in turn affects the quality of the road function; since the SASW method relies on the propagation characteristics of surface waves, factors such as work area noise, signal attenuation, spatial aliasing and near-field effects may affect the accuracy of the measurement results. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a method, system, equipment and medium for rapid nondestructive testing of cement pavement;

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A rapid nondestructive testing method for cement pavement, comprising:

[0007] The seismic source pulse signal is received by a receiver placed vertically on the measuring road surface, and a reverse seismic source secondary measurement is performed according to the arrangement mode of the seismic source and the receiver. The measured seismic source pulse signal is averaged to obtain the on-site measured signal;

[0008] Constructing a dispersion curve according to the field measured signal, and inverting and analyzing the elastic modulus information at different depths under the road surface according to the dispersion curve;

[0009] The road surface damage degree and location are calculated by combining the road surface structural parameters and the elastic modulus information through a nondestructive testing model, and a cement road surface test report is finally output based on the calculated damage degree and location.

[0010] Specifically, the signal averaging method is: using time domain averaging technology to superimpose and average multiple source pulse signals collected to eliminate random noise and improve the signal-to-noise ratio of the signal. The time domain averaging technology includes time alignment of the collected signals, and then arithmetic averaging of the aligned signals to obtain clearer on-site measured signals.

[0011] Specifically, the method for secondary measurement of the inverted source is: setting the forward configuration direction according to the positions of the two receivers, and performing tests at both ends of the receiver respectively. During the test, the forward configuration direction is first executed, and the source is moved to the other side without moving the original position of the receiver, and the input channel of the recording device is switched so that the far-end receiver in the forward configuration direction becomes the near-end receiver being tested, and then the test is performed again.

[0012] Specifically, the arrangement mode of the source and the receiver is to keep the centerline position of the two receivers unchanged, and change the distance between the receivers to repeat the test.

[0013] Specifically, the method for constructing the dispersion curve is: according to the time domain information of the field measured signal, the Fourier transform is used to convert it into the frequency domain, and the transfer function and the impulse response are calculated. The calculation formula is:

[0014]

[0015] h(t)=∫H YX (f) e i2πft dx,

[0016] Among them, H YX is the transfer function, h(t) is the impulse response, A Y , A X is the spectrum amplitude, φ Y ,φ X is the phase angle of the time domain signal, φ Y -φ X is the phase difference of the time domain signals of the two receivers, e i2πft It represents a polyphonic signal with frequency f as parameter, which contains amplitude and phase information. dx represents the integral of frequency, which is used to accumulate the integral of different frequencies to H. YX (f) contribution;

[0017] The cross power spectrum and the coherence function are calculated according to the frequency domain signal, the phase velocity and the corresponding frequency are obtained based on the phase difference information of the cross power spectrum and the coherence function, and the dispersion curve is constructed according to the phase velocity and the frequency. The calculation formula is:

[0018]

[0019] V ph =D / (φ(f) / 2π)·f,

[0020] Among them, G YX is the cross power spectrum, G XX , G YY is the auto-power spectrum recorded by the two receivers, N is the total number of sampling points of the signal, Y i is the signal value of the i-th sampling point of the near-end receiver, is the signal value of the i-th sampling point of the remote receiver, γ 2 is the coherence function, which evaluates the quality of the recorded surface wave signal based on the signal-to-noise ratio, φ(f) is the phase difference at frequency f, Im(G YX )、Re(G YX ) represent the cross power spectrum G YX The imaginary and real parts, V ph is the phase velocity, D is the distance between the receivers, and f is the frequency.

[0021] Specifically, the inversion analysis method is: according to the dispersion curve, the maximum likelihood method is used to evaluate the degree of agreement between the theoretical dispersion curve and the experimental dispersion curve, so as to determine the best fitting parameters; through iterative calculation, the model parameters are continuously adjusted until the difference between the theoretical dispersion curve and the experimental dispersion curve is minimized, and the elastic modulus information of the cement pavement is obtained. The elastic modulus information is calculated by the distribution of shear wave velocity using the linear elastic theory, and the calculation formula is:

[0022]

[0023] Where E is the elastic modulus, ρ is the density of the pavement material, V S is the shear wave velocity and μ is the Poisson’s ratio.

[0024] Specifically, the nondestructive testing model adopts a multi-layer perceptron network structure to automatically identify and locate the damaged area of ​​the road surface by learning the input road elastic modulus information and structural parameters; during the model training process, a large amount of road surface data with known damage degree and location is used for supervised learning to improve the prediction accuracy and generalization ability of the model; the nondestructive testing model receives on-site measured signals and road surface structural parameters as input, and outputs the damage degree and location information of the cement road surface.

[0025] A cement pavement rapid nondestructive testing system, comprising: a data acquisition module, a data processing module, and a damage assessment module;

[0026] The data acquisition module is used to receive the source pulse signal through a receiver placed vertically on the measured road surface, perform a secondary measurement of the reverse source according to the arrangement mode of the source and the receiver, and obtain the field measured signal after signal averaging processing on the measured source pulse signal;

[0027] The data processing module is used to construct a dispersion curve according to the on-site measured signal, and inversely analyze the elastic modulus information at different depths under the road surface according to the dispersion curve;

[0028] The damage assessment module is used to combine the pavement structure parameters and the elastic modulus information, calculate the damage degree and location of the pavement through a non-destructive testing model, and finally output a cement pavement inspection report based on the calculated damage degree and location.

[0029] The beneficial effects of the present invention are:

[0030] The non-destructive testing model can effectively evaluate the structural integrity of cement pavement, significantly improve the efficiency and accuracy of cement pavement damage detection, quickly locate the damaged area, and provide a scientific basis for timely maintenance. By adopting non-destructive testing technology and setting the layout mode of the source and receiver, the unevenness of the road surface, such as cracks, cavities and other defects, can be identified by comparing the dispersion curves at different positions; this method not only improves the accuracy of detection, but also greatly shortens the detection time and reduces the damage to the road surface, prolongs the service life of the road, and reduces maintenance costs. The system is easy to operate and easy to deploy on site. It is suitable for pavement detection in various complex environments and has good adaptability and flexibility. Through real-time data collection and processing, it can provide reliable data support for road maintenance decisions, which helps to realize the intelligent and refined management of road maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0032] Figure 1 The present invention is a schematic flow chart of a rapid nondestructive testing method for cement pavement. DETAILED DESCRIPTION

[0033] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0034] See also Figure 1 , a rapid nondestructive testing method for cement pavement, comprising:

[0035] The seismic source pulse signal is received by a receiver placed vertically on the measuring road surface, and a reverse seismic source secondary measurement is performed according to the arrangement mode of the seismic source and the receiver. The measured seismic source pulse signal is averaged to obtain the on-site measured signal;

[0036] Constructing a dispersion curve according to the field measured signal, and inverting and analyzing the elastic modulus information at different depths under the road surface according to the dispersion curve;

[0037] The road surface damage degree and location are calculated by combining the road surface structural parameters and the elastic modulus information through a nondestructive testing model, and a cement road surface test report is finally output based on the calculated damage degree and location.

[0038] In this embodiment, it is mainly used to measure the surface wave between two receivers located at a known distance on the ground. Using a small hammer as an impact source to hit the ground will generate surface wave signals in different frequency ranges; two receivers are placed vertically on both sides of the measurement point to form a straight line, so as to receive the surface wave signal. The received signal is pre-processed by a dynamic spectrum analyzer. The sampling rate of the system is 20 microseconds, the total data points of a single sampling are 1024, the total duration of the time domain signal is 7168 microseconds, and the highest frequency of the signal can be as high as 7kHz. During the measurement process, the distance between the two receivers should be set equal to the distance between the first receiver and the impact source; and at each measurement point, it is required to repeat several experiments (not less than 6 times) by gradually increasing the distance between the receivers (such as 2 / 4 / 6 / 8 times). The distance between the receivers is related to the received Rayleigh wavelength: the longer the distance, the longer the wavelength of the Rayleigh wave can be detected, and signals covering different wavelength ranges are obtained, so that deeper formation properties can be obtained.

[0039] Specifically, the signal averaging method is: using time domain averaging technology to superimpose and average multiple source pulse signals collected to eliminate random noise and improve the signal-to-noise ratio of the signal. The time domain averaging technology includes time alignment of the collected signals, and then arithmetic averaging of the aligned signals to obtain clearer on-site measured signals.

[0040] Specifically, the method for secondary measurement of the inverted source is: setting the forward configuration direction according to the positions of the two receivers, and performing tests at both ends of the receiver respectively. During the test, the forward configuration direction is first executed, and the source is moved to the other side without moving the original position of the receiver, and the input channel of the recording device is switched so that the far-end receiver in the forward configuration direction becomes the near-end receiver being tested, and then the test is performed again.

[0041] Specifically, the arrangement mode of the source and the receiver is to keep the centerline position of the two receivers unchanged, and change the distance between the receivers to repeat the test.

[0042] Specifically, the method for constructing the dispersion curve is: according to the time domain information of the field measured signal, the Fourier transform is used to convert it into the frequency domain, and the transfer function and the impulse response are calculated. The calculation formula is:

[0043]

[0044] h(t)=∫H YX (f) e i2πft dx,

[0045] Among them, H YX is the transfer function, h(t) is the impulse response, A Y , A X is the spectrum amplitude, φ Y ,φ X is the phase angle of the time domain signal, φ Y -φ X is the phase difference of the time domain signals of the two receivers, e i2πft It represents a polyphonic signal with frequency f as parameter, which contains amplitude and phase information. dx represents the integral of frequency, which is used to accumulate the integral of different frequencies to H. YX (f) contribution;

[0046] The cross power spectrum and the coherence function are calculated according to the frequency domain signal, the phase velocity and the corresponding frequency are obtained based on the phase difference information of the cross power spectrum and the coherence function, and the dispersion curve is constructed according to the phase velocity and the frequency. The calculation formula is:

[0047]

[0048] V ph =D / (φ(f) / 2π)·f,

[0049] Among them, G YX is the cross power spectrum, G XX , G YY is the auto-power spectrum recorded by the two receivers, N is the total number of sampling points of the signal, Y i is the signal value of the i-th sampling point of the near-end receiver, is the signal value of the i-th sampling point of the remote receiver, γ 2 is the coherence function, which evaluates the quality of the recorded surface wave signal based on the signal-to-noise ratio, φ(f) is the phase difference at frequency f, Im(G YX )、Re(G YX ) represent the cross power spectrum G YX The imaginary and real parts, V phis the phase velocity, D is the distance between the receivers, and f is the frequency.

[0050] Specifically, the inversion analysis method is: according to the dispersion curve, the maximum likelihood method is used to evaluate the degree of agreement between the theoretical dispersion curve and the experimental dispersion curve, so as to determine the best fitting parameters; through iterative calculation, the model parameters are continuously adjusted until the difference between the theoretical dispersion curve and the experimental dispersion curve is minimized, and the elastic modulus information of the cement pavement is obtained. The elastic modulus information is calculated by the distribution of shear wave velocity using the linear elastic theory, and the calculation formula is:

[0051]

[0052] Where E is the elastic modulus, ρ is the density of the pavement material, V S is the shear wave velocity and μ is the Poisson’s ratio.

[0053] Specifically, the nondestructive testing model adopts a multi-layer perceptron network structure to automatically identify and locate the damaged area of ​​the road surface by learning the input road elastic modulus information and structural parameters; during the model training process, a large amount of road surface data with known damage degree and location is used for supervised learning to improve the prediction accuracy and generalization ability of the model; the nondestructive testing model receives on-site measured signals and road surface structural parameters as input, and outputs the damage degree and location information of the cement road surface.

[0054] In this embodiment, the multi-layer perceptron network structure of the non-destructive testing model includes an input layer, a hidden layer, and an output layer. The input layer receives the pavement elastic modulus information and structural parameters, the hidden layer processes the input data through a nonlinear activation function, and the output layer identifies and locates the damaged area based on the learned features. During the model training phase, the network weights are adjusted through the back propagation algorithm to minimize the error between the predicted results and the actual damage data. In addition, in order to further improve the performance of the model, regularization technology is used to prevent overfitting, and model parameters are optimized through methods such as cross-validation. Ultimately, the non-destructive testing model can efficiently and accurately provide a scientific basis for the maintenance and repair of cement pavements.

[0055] A cement pavement rapid nondestructive testing system, comprising: a data acquisition module, a data processing module, and a damage assessment module;

[0056] The data acquisition module is used to receive the source pulse signal through a receiver placed vertically on the measured road surface, perform a secondary measurement of the reverse source according to the arrangement mode of the source and the receiver, and obtain the field measured signal after signal averaging processing on the measured source pulse signal;

[0057] The data processing module is used to construct a dispersion curve according to the on-site measured signal, and inversely analyze the elastic modulus information at different depths under the road surface according to the dispersion curve;

[0058] The damage assessment module is used to combine the pavement structure parameters and the elastic modulus information, calculate the damage degree and location of the pavement through a non-destructive testing model, and finally output a cement pavement inspection report based on the calculated damage degree and location.

[0059] The computer storage medium of the embodiment of the present invention may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, device or device.

[0060] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0061] The program code included on the computer readable medium can be transmitted with any appropriate medium, including but not limited to wireless, electric wire, optical cable, RF, etc., or any suitable combination of the above. The computer program code for performing the operation of the present invention can be written in one or more programming languages ​​or their combinations, and the programming language includes object-oriented programming languages-such as Java, Smalltalk, C++, and also includes conventional procedural programming languages-such as "C" language or similar programming languages. The program code can be executed completely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on the remote computer, or completely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0062] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A rapid nondestructive testing method for cement pavement, characterized in that: include: The seismic source pulse signal is received by a receiver placed vertically on the measuring road surface, and a reverse seismic source secondary measurement is performed according to the arrangement mode of the seismic source and the receiver. The arrangement mode of the seismic source and the receiver is to keep the center line position of the two receivers unchanged and change the distance between the receivers to repeat the test; the measured seismic source pulse signal is averaged to obtain the field measured signal; Constructing a dispersion curve according to the field measured signal, and inverting and analyzing the elastic modulus information at different depths under the road surface according to the dispersion curve; Combining the pavement structure parameters and the elastic modulus information, the damage degree and location of the pavement are calculated through a nondestructive testing model, and a cement pavement test report is finally outputted based on the calculated damage degree and location; The method of reversing the source for secondary measurement is: setting the forward configuration direction according to the positions of the two receivers, and testing at both ends of the receivers respectively. During the test, the forward configuration direction is firstly executed, the source is moved to the other side without moving the original position of the receiver, and the input channel of the recording device is switched so that the far-end receiver in the forward configuration direction becomes the near-end receiver under test, and then the test is performed again; The signal averaging processing method is: using time domain averaging technology to superimpose and average multiple source pulse signals collected to eliminate random noise and improve the signal-to-noise ratio of the signal; the time domain averaging technology includes time alignment of the collected signals, and then arithmetic averaging of the aligned signals to obtain the field measured signals.

2. The method according to claim 1, characterized in that The method for constructing the dispersion curve is: according to the time domain information of the field measured signal, the Fourier transform is used to convert it into the frequency domain, and the transfer function and the impulse response are calculated. The calculation formula is: h(t)=fH YX (f)·e i2πft dx, Among them, H YX is the transfer function, h(t) is the impulse response, A Y , A X is the spectrum amplitude, φ Y ,φ X is the phase angle of the time domain signal, φ Y -φ X is the phase difference of the time domain signals of the two receivers, e i2πft It represents a polyphonic signal with frequency f as parameter, which contains amplitude and phase information. dx represents the integral of frequency, which is used to accumulate the integral of different frequencies to H. YX (f) contribution; The cross power spectrum and the coherence function are calculated according to the frequency domain signal, the phase velocity and the corresponding frequency are obtained based on the phase difference information of the cross power spectrum and the coherence function, and the dispersion curve is constructed according to the phase velocity and the frequency. The calculation formula is: γ 2 (=|G YX (f)| 2 / G XX (f)·G YY (f), φ(f)=tan -1 [In(G YX ) / Re(G YX )], V ph =D / (φ(f / 2π)·f, Among them, G YX is the cross power spectrum, G XX , G YY is the auto-power spectrum recorded by the two receivers, N is the total number of sampling points of the signal, Y i is the signal value of the i-th sampling point of the near-end receiver, is the signal value of the i-th sampling point of the remote receiver, γ 2 is the coherence function, which evaluates the quality of the recorded surface wave signal based on the signal-to-noise ratio, φ(f) is the phase difference at frequency f, Im(G YX )、Re(G YX ) represent the cross power spectrum G YX The imaginary and real parts, V ph is the phase velocity, D is the distance between the receivers, and f is the frequency.

3. The method according to claim 1, characterized in that The inversion analysis method is: according to the dispersion curve, the maximum likelihood method is used to evaluate the degree of agreement between the theoretical dispersion curve and the experimental dispersion curve, so as to determine the best fitting parameters; through iterative calculation, the model parameters are continuously adjusted until the difference between the theoretical dispersion curve and the experimental dispersion curve is minimized, and the elastic modulus information of the cement pavement is obtained. The elastic modulus information is calculated by the distribution of shear wave velocity using the linear elastic theory, and the calculation formula is: Where E is the elastic modulus, ρ is the density of the pavement material, V S is the shear wave velocity and μ is the Poisson’s ratio.

4. The method according to claim 1, characterized in that The nondestructive testing model adopts a multi-layer perceptron network structure, and automatically identifies and locates the damaged area of ​​the road surface by learning the input road surface elastic modulus information and structural parameters; during the model training process, a large amount of road surface data with known damage degree and location is used for supervised learning to improve the prediction accuracy and generalization ability of the model; the nondestructive testing model receives the field measured signal and road surface structural parameters as input, and outputs the damage degree and location information of the cement road surface.

5. A cement pavement rapid nondestructive testing system, used to perform a cement pavement rapid nondestructive testing method according to any one of claims 1 to 4, characterized in that: include: Data acquisition module, data processing module, damage assessment module; The data acquisition module is used to receive the source pulse signal through a receiver placed vertically on the measured road surface, perform a secondary measurement of the reverse source according to the arrangement mode of the source and the receiver, and obtain the field measured signal after signal averaging processing on the measured source pulse signal; The data processing module is used to construct a dispersion curve according to the on-site measured signal, and inversely analyze the elastic modulus information at different depths under the road surface according to the dispersion curve; The damage assessment module is used to combine the pavement structure parameters and the elastic modulus information, calculate the damage degree and location of the pavement through a non-destructive testing model, and finally output a cement pavement inspection report based on the calculated damage degree and location.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, a rapid non-destructive testing method for cement pavement as described in any one of claims 1-4 is implemented.

7. A storage medium containing computer executable instructions, characterized in that: The computer executable instructions, when executed by a computer processor, are used to execute a cement pavement rapid non-destructive testing method as described in any one of claims 1-4.

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