Rayleigh surface wave detection method and detection system for steel-concrete joint surface defects

Abstract

The invention discloses a Rayleigh surface wave detection method and system for steel-concrete joint surface defects, and the method comprises the steps: S1, determining the center frequency f0 and the incident angle theta of an air coupling probe according to the parameters of a detected target, so as to enable the air coupling probe to form Rayleigh surface waves in the detected target; s2, selecting an air coupling probe matched with the center frequency f0 as an excitation probe and a receiving probe, building a Rayleigh surface wave detection system, and calibrating the propagation velocity v and the attenuation coefficient alpha of the Rayleigh surface wave for a detected target; s3, scanning and detecting the detected target from one side of the steel plate by adopting a Rayleigh surface wave detection system; and if the defect exists, determining the position and the transverse size of the defect. According to the method, the parameters of the Rayleigh surface wave of the detection carrier are determined through theoretical analysis and experimental calibration, the signal-to-noise ratio of excited signals is high, and the defect recognition sensitivity is high.

Description

Technical Field

[0001] The invention relates to the field of nondestructive testing of buildings, and in particular to a Rayleigh surface wave detection method and a detection system for defects on a steel-concrete interface. Background Art

[0002] Steel-concrete composite structures such as steel tube concrete, steel plate concrete, and steel-concrete composite beams give full play to the mechanical properties of steel and concrete materials, improve the stiffness, bearing capacity, and seismic toughness of the structure, and have been widely used in high-rise and super-high-rise buildings, large-span bridges, cross-sea tunnels and other structures. During the construction process, affected by the construction technology, personnel quality, and complex environment, the steel-concrete interface is prone to defects such as looseness, voids, and inclusions, which will seriously reduce the mechanical and seismic performance of the steel-concrete composite structure. Therefore, accurately identifying and controlling defects at the construction site is crucial to evaluating the safety performance of the entire structural system.

[0003] At present, there are two methods for detecting defects on the interface between steel and concrete: ultrasonic method and ultrasonic phased array imaging method. The invention patent "A device and method for detecting the bonding quality of concrete steel plate" (application number: CN201811492889.4) introduces a method of exciting and receiving longitudinal waves on the concrete side using an air-coupled probe, and judging the bonding quality of the concrete and steel plate interface by the waveform phase. However, this method is to detect on the concrete side, and the wavelength of the excited ultrasonic wave is large, the defect recognition ability is weak, and the defect size cannot be quantified. Regarding the ultrasonic phased array imaging method for detecting defects on the steel-concrete interface, the invention patents "A method for detecting the quality of the interface between new and old concrete for strengthening concrete structures" (application number: CN202010628895.9) and "An ultrasonic phased array system and steel tube concrete construction method and process" (application number: CN202210434404.6) introduce the ultrasonic phased array imaging method to judge the construction quality of the steel-concrete interface based on ultrasonic images, but the ultrasonic phased array equipment used in this method mostly uses low-frequency ultrasonic waves as the detection carrier, with a large wavelength and poor defect recognition accuracy. At the same time, the thickness of concrete in the steel-concrete composite structure is much greater than the thickness of the steel plate, and the defects on the steel-concrete interface are located on the surface of the steel-concrete composite structure. Both the ultrasonic method and the ultrasonic phased array imaging method are based on low-frequency longitudinal wave signals for defect detection, with large wavelengths and poor detection accuracy, which cannot meet the needs of accurate evaluation of the mechanical properties of steel-concrete composite structures. Summary of the invention

[0004] In view of the above technical problems, the present invention uses Rayleigh surface waves to quickly identify defects on the interface between steel and concrete, achieves accurate treatment of defects on the interface between steel and concrete, and eliminates safety hazards in a timely manner. To achieve the above objectives, the technical solutions of the present invention include:

[0005] A Rayleigh surface wave detection method for steel-concrete interface defects, comprising the following steps:

[0006] S1: According to the parameters of the target to be measured, the center frequency f0 and the incident angle θ of the air-coupled probe are determined so that the air-coupled probe forms a Rayleigh surface wave in the target to be measured;

[0007] S2: Select an air-coupled probe that matches the center frequency f0 as the excitation probe and the receiving probe, build a Rayleigh surface wave detection system, and calibrate the propagation velocity v and attenuation coefficient α of the Rayleigh surface wave for the target to be measured;

[0008] S3: From one side of the steel plate, the Rayleigh surface wave detection system is used to scan and detect the target; if there is a defect, the defect position and lateral size are determined.

[0009] A further improvement of the present invention is that in step S1:

[0010] The parameters of the measured target include: the thickness of the steel h s , the thickness of the concrete slab h c , the density of steel ρ s , the density of the concrete slab ρ c , elastic modulus E of steel s , the elastic modulus E of the concrete slab c , Poisson's ratio of steel μ s , Poisson's ratio μ of the concrete slab c , air density ρ a and the air sound speed c a ;

[0011] Based on the circulant matrix algorithm and spring model, the phase velocity dispersion curve of ultrasonic guided waves in a two-layer medium structure such as a steel and concrete composite structure is calculated to extract the phase velocity c of the Rayleigh surface wave. R ; Determine the center frequency f0 of the air-coupled probe and quantitatively calculate the incident angle θ according to Snell's law:

[0012]

[0013] Where: c a is the air sound speed, c R is the phase velocity of the Rayleigh surface wave.

[0014] A further improvement of the present invention is that in step S2, the process of calibrating the propagation velocity v and the attenuation coefficient α of the Rayleigh surface wave for the measured target specifically includes: turning on the power supply, adjusting the excitation unit voltage and the gain of the signal amplifier, debugging the Rayleigh surface wave signal until a signal with a high signal-to-noise ratio is obtained, and automatically calibrating the Rayleigh surface wave propagation velocity v and the attenuation coefficient α using the embedded software in the data processing unit:

[0015]

[0016] Where: L i represents the propagation distance at the i-th measurement line, t i represents the propagation time at the i-th survey line, A i0 represents the initial energy of the Rayleigh surface wave at the i-th line, A i represents the propagation of Rayleigh surface wave L at the i-th line i The energy after the measurement, i = 1, 2, 3...N represents the number of the measuring line on the measured target; the larger the value of N is, the more accurate the Rayleigh surface wave propagation velocity v and the attenuation coefficient α are, and N should not be less than 5.

[0017] A further improvement of the present invention is that in step S2, the calculation formula of the signal-to-noise ratio SNR is:

[0018]

[0019] Among them: A S is the maximum amplitude of the Rayleigh surface wave signal, A N It is the maximum amplitude of the noise in the received ultrasonic signal. A high signal-to-noise ratio generally requires an SNR of no less than 20.

[0020] A further improvement of the present invention is that step S3 specifically includes: fixing the spacing between the excitation probe and the receiving probe, using the automated detection module to drive the excitation probe and the receiving probe to perform automated line scanning on a preset detection path on the steel plate side; synchronously collecting and storing the Rayleigh surface wave signal at each measuring point through a data acquisition unit; after compensating for its attenuation, performing line scanning imaging based on the waveform at each measuring point, and automatically judging whether there are defects on the steel-concrete interface.

[0021] A further improvement of the present invention is that in step S3, if there is a defect, an automated detection module is used to set a detection path perpendicular to the original detection path on the side of the steel plate to perform automated line scanning, and mark the suspected defect area; then the automated detection module is used to adjust the probe spacing and the scanning spacing, and fine scanning and imaging are performed along a Z shape in the suspected defect area to quantitatively determine the defect position and lateral size.

[0022] A further improvement of the present invention is that if a defect is detected in step S3, the defect is managed, and the management process includes:

[0023] S41: On the steel plate side near the center of the detected steel-concrete interface defect, a hole is drilled using an impact drill, and after cleaning the debris, the distribution characteristics of the defect are checked using endoscope imaging, and the lateral size of the defect is measured;

[0024] S42: According to the endoscope inspection results, a plan for making the rough surface of concrete at the defect is designed, a grinder is used to make the rough surface, and dust in the defect is cleaned;

[0025] S43: After pouring water into the defects through the holes, high-fluidity concrete is poured into the defects of the steel-concrete interface using a concrete pouring unit, and then curing is performed after sufficient vibration;

[0026] S44: Clean the rust, dust, oil and other debris on the surface of the steel plate near the hole, use welding rods and electric welding machines to weld and fill the hole, and grind it flat after cooling;

[0027] S45: After applying one coat of sealing primer on the repaired holes in the steel plate and its surroundings, apply three coats of high-strength, flexible, corrosion-resistant waterproof coating for waterproof and anti-corrosion treatment. The construction time interval between two adjacent coats is 20h to 22h.

[0028] The present invention also provides a steel-concrete interface defect detection system, which is used to implement the above-mentioned Rayleigh surface wave detection method for steel-concrete interface defects, and is characterized by comprising: a signal excitation module, a signal receiving and display module, and an automatic detection module;

[0029] The signal excitation module includes: a power supply, an excitation unit, an excitation probe and a signal synchronization unit;

[0030] The signal receiving and display module includes: a receiving probe, a signal amplifier, a data acquisition unit, a data processing unit and a display unit;

[0031] The automatic detection module includes: a mechanical unit, an electric control unit, a power unit and a sound absorption unit.

[0032] A further improvement of the present invention is that it also includes a steel-concrete interface defect treatment module, which includes: an impact drill, an endoscope, a grinder, a concrete pouring unit, welding rods and an electric welder; the concrete pouring unit includes a motor, an electric controller, a mixer, a pressurizer, a pumping pipe and a vibrating rod.

[0033] The beneficial effects of the present invention include:

[0034] 1) The parameters of the Rayleigh surface wave of the detection carrier are determined through theoretical analysis and experimental calibration, and the signal-to-noise ratio of the excited signal is high, and the defect recognition sensitivity is high;

[0035] 2) Use air-coupled probes to automatically detect defects on the steel-concrete interface, which is easy to operate on site and has high detection efficiency;

[0036] 3) Through automated detection, the drilling position for defect treatment on the steel-concrete interface is accurately located, and a complete defect treatment process including defect calibration, rough surface setting, concrete pouring, hole repair, and anti-rust and waterproofing treatment is proposed, which is highly targeted, low-cost and effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A steel-concrete interface defect detection system in the present invention;

[0038] Figure 2 It is a principle block diagram of the concrete pouring unit in the present invention;

[0039] Figure 3 Flow chart of detection and treatment of steel-concrete interface defects in this embodiment;

[0040] Figure 4 Schematic diagram of Rayleigh surface wave propagation in a steel and concrete composite structure in an embodiment;

[0041] Figure 5 Schematic diagram of oblique-incidence detection of air-coupled Rayleigh surface waves in a steel-concrete composite structure in an embodiment;

[0042] Figure 6 It is a schematic diagram of the principle of steel-concrete interface defect detection based on air-coupled Rayleigh surface waves in the present invention;

[0043] Figure 7 It is a schematic diagram of calibration of Rayleigh surface wave propagation velocity and attenuation coefficient in the present invention;

[0044] Figure 8 This is a schematic diagram of rapid large-scale scanning and identification of steel-concrete interface defects in the present invention;

[0045] Fig. 9 It is a schematic diagram of local refined scanning detection of defects on the steel-concrete interface in the present invention. DETAILED DESCRIPTION

[0046] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0047] like Figure 1As shown, an embodiment of the present invention provides an automatic detection system for steel-concrete interface defects, which includes a signal excitation module 1, a signal receiving and display module 2, an automatic detection module 3 and a steel-concrete interface defect treatment module 4; the signal excitation module 1 includes: a power supply 11, an excitation unit 12, an excitation probe 13 and a signal synchronization unit 14; the signal receiving and display module 2 includes: a receiving probe 21, a signal amplifier 22, a data acquisition unit 23, a data processing unit 24 and a display unit 25; the automatic detection module 3 includes: a mechanical unit 31, an electronic control unit 32, a power unit 33 and a sound absorption unit 34; the steel-concrete interface defect treatment module 4 includes: an impact drill 41, an endoscope 42, a grinder 43, a concrete pouring unit 44, an electric welding rod 45 and an electric welding machine 46; please refer to Figure 2 The concrete pouring unit 44 includes a motor 441, an electric controller 442, a mixer 443, a pressurizer 444, a pumping pipe 445 and a vibrator 446. The signal receiving and display module 2 feeds back the detection result of the steel-concrete interface defect to the steel-concrete interface defect treatment module 4, thereby realizing rapid detection and precise treatment of steel-concrete interface defects. Both the excitation probe 13 and the receiving probe 21 are air-coupled probes.

[0048] This embodiment also provides a Rayleigh surface wave detection method for steel-concrete interface defects, which is implemented using the above-mentioned steel-concrete interface defect automatic detection system; the method comprises:

[0049] S1: According to the parameters of the target to be measured, the center frequency f0 and the incident angle θ of the air-coupled probe are determined so that the air-coupled probe forms a Rayleigh surface wave in the target to be measured;

[0050] S2: Select an air-coupled probe that matches the center frequency f0 as the excitation probe and the receiving probe, build a Rayleigh surface wave detection system, and calibrate the propagation velocity v and attenuation coefficient α of the Rayleigh surface wave for the target to be measured;

[0051] S3: From one side of the steel plate, the Rayleigh surface wave detection system is used to scan and detect the target; if there is a defect, the defect position and lateral size are determined.

[0052] In this embodiment, Rayleigh surface waves are elastic waves propagating on the surface of the steel and concrete composite structure. Figure 4, its wave direction is perpendicular to the surface of the composite structure, presenting an elliptical vibration, and the energy is mainly concentrated near the surface of the medium, and decays rapidly with increasing thickness. Since the thickness of steel in the steel-concrete composite structure is much smaller than the thickness of concrete, Rayleigh surface waves can be used to detect defects on the steel-concrete interface. When there are no defects on the propagation path of the Rayleigh surface wave on the surface of the steel-concrete composite structure, after removing the attenuation of the ultrasonic wave, its signal amplitude does not change much; please refer to Figure 6 When Rayleigh surface waves encounter defects on the propagation path, reflection, diffraction and scattering will occur. After eliminating the influence of attenuation, its wave packet and signal amplitude will change significantly, accompanied by mode conversion. By analyzing the wave packet and signal amplitude of the Rayleigh surface wave signal, it can be determined whether there are defects on the steel-concrete interface.

[0053] The method of this embodiment uses Rayleigh surface waves as the detection carrier and performs defect detection through automated scanning imaging, which solves the problem of difficulty in accurately identifying defects on the steel-concrete interface in existing detection technologies. The method of this embodiment also includes a defect treatment process; the treatment process uses a variety of instruments to accurately treat defects on the steel-concrete interface in a minimally invasive manner, filling the gap in the existing technology. Specifically:

[0054] Step S1 specifically includes: according to the thickness h of the steel and concrete slabs s / h c , density ρ s / ρ c , elastic modulus E s / E c and Poisson's ratio μ s / μ c , and air density ρ a and the speed of sound c a Based on the circulant matrix algorithm and spring model, the phase velocity dispersion curve of ultrasonic guided waves in two-layer medium structures such as steel and concrete composite structures is calculated to extract the phase velocity c of Rayleigh surface waves. R , determine the center frequency f0 of the air-coupled probe, and quantitatively calculate the incident angle θ according to Snell's law:

[0055]

[0056] In this step, the center frequency f0 is usually larger than that of conventional ultrasonic guided wave detection methods, and is between 200kHz and 20MHz. The propagation speed of Rayleigh surface waves hardly changes with frequency near the center frequency f0, which makes Rayleigh surface waves easier to be excited than other modes of ultrasonic guided waves, making the received signal mode single, easier to process, and easier to judge defects.

[0057] Step S2 specifically includes: selecting an air-coupled excitation probe 13 and a receiving probe 21 that match the center frequency f0, see Figure 5 , build the Rayleigh surface wave detection system, turn on the power supply 11, adjust the voltage of the excitation unit 12 and the gain of the signal amplifier 22, and debug the Rayleigh surface wave signal until a signal with a high signal-to-noise ratio is obtained. Please refer to Figure 7 , the embedded software in the data processing unit 24 is used to automatically calibrate the Rayleigh surface wave propagation velocity v and the attenuation coefficient α:

[0058]

[0059] Where L i represents the propagation distance at the i-th measurement line, t i represents the propagation time at the i-th survey line, A i0 represents the initial energy of the Rayleigh surface wave at the i-th line, A i represents the propagation of Rayleigh surface wave L at the i-th line i The specific reason for calibration is that there are certain differences between the actual characteristics of steel and concrete and the theoretical values ​​of the corresponding numbers, which will lead to certain deviations between the actual propagation speed and attenuation coefficient of Rayleigh surface waves and the theoretical calculated values.

[0060] Step S3 specifically includes: fixing the distance between the excitation probe 13 and the receiving probe 21, see Figure 8 , the detection path is set on the steel plate side by the automatic detection module 3 for automatic line scanning. The process is a fast scan. The Rayleigh surface wave signals at different measuring points are synchronously collected and stored by the data acquisition unit. After compensating for the attenuation of the Rayleigh surface wave propagation velocity v and the attenuation coefficient α calibrated in step S2, the embedded software in the data processing unit 24 is used to perform line scanning imaging based on the waveforms at different measuring points to automatically determine whether there are defects on the steel-concrete interface.

[0061] If there are defects, a detailed scan is performed. During the detailed scan, the automatic detection module 3 is used to set a detection path perpendicular to the original detection path on the steel plate side to perform automatic line scanning and mark the suspected defect area; please refer to Fig. 9 , and then use the automated detection module 3 to adjust the probe spacing and scanning spacing, and perform fine scanning imaging in the suspected defect area along the "z" shape to quantitatively determine the defect position and lateral size. In the process of detailed scanning of the defect area, the spacing between the scanning lines and the spacing between adjacent measuring points are smaller than the fast scanning process. Scanning parameter Δl f With l f , Δw f With w f The value of should satisfy:

[0062]

[0063] Whether there is a defect on the steel-concrete interface at the measuring point is mainly determined by the wave packet and signal amplitude of the signal received by the receiving probe. In some embodiments, the signal amplitude can be used for judgment; the mode of the received signal can also be analyzed by signal processing means to determine whether a mode conversion occurs. If a mode conversion occurs, it indicates that there is a defect; in other embodiments, a convolutional neural network can be used to identify and process the sequence of received signals; in the process of constructing a convolutional neural network, the sequences of received signals of normal measuring points and measuring points with defects can be collected respectively to train the convolutional neural network.

[0064] S4: Treatment of steel-concrete interface defects, including the following steps:

[0065] S41: On the steel plate side near the center of the detected steel-concrete interface defect, a percussion drill 41 is used to drill a hole, and after cleaning the debris, an endoscope 42 is used to image and verify the distribution characteristics of the defect, and the lateral size of the defect is measured;

[0066] S42: According to the endoscope inspection results, a plan for making a rough surface of concrete at the defect is designed, a grinder 43 is used to make the rough surface, and dust in the defect is cleaned;

[0067] S43: After pouring water into the defect through the hole, a concrete pouring unit 44 is used to pour high-fluidity concrete into the defect of the steel-concrete interface, and curing is performed after sufficient vibration;

[0068] S44: cleaning the rust, dust, oil and other debris on the surface of the steel plate near the hole, welding and filling the hole with a welding rod 45 and a welding machine 46, and grinding it flat after cooling;

[0069] S45: After applying one coat of sealing primer on the repaired holes in the steel plate and its surroundings, apply three coats of high-strength, flexible, corrosion-resistant waterproof coating for waterproof and anti-corrosion treatment. The construction time interval between two adjacent coats is 20h to 22h.

[0070] In this embodiment, in step S1, as the frequency-thickness product (the product of the thickness of the steel and concrete composite structure and the frequency) increases, the 0th order antisymmetric mode and the 0th order symmetric mode of the ultrasonic guided wave in the steel and concrete composite structure gradually degenerate into Rayleigh surface waves, and their propagation speed c R It is the phase velocity of the 0th order antisymmetric mode in the phase velocity dispersion curve of the combined structure, and remains unchanged. Due to the differences in material properties, it is necessary to further calibrate the propagation velocity of the Rayleigh surface wave.

[0071] Optionally, in step S2, the calculation formula of the signal-to-noise ratio SNR is:

[0072]

[0073] Among them A S is the maximum amplitude of the Rayleigh surface wave signal, A N It is the maximum amplitude of the noise in the received ultrasonic signal. A high signal-to-noise ratio generally requires an SNR of no less than 20. The larger the value of N, the more accurate the Rayleigh surface wave propagation velocity v and the attenuation coefficient α. N should not be less than 5.

[0074] In step S2, the embedded software in the data processing unit 24 is developed based on Python language, and has the functions of automatic extraction of acoustic time and signal amplitude, line scan imaging, B-scan focus imaging, defect contour extraction and automatic calculation of defect length, etc. It can quickly give the detection results at the engineering site, and the recognition accuracy of the defect length can reach 1mm.

[0075] In step S41 , the drill bit specification of the impact drill 41 can be selected from φ10, φ20, φ30 and φ50, etc. The selected drill bit specification should match the diameter of the measuring lens of the endoscope 42 and the diameter of the pumping pipe 445 of the concrete pouring unit 44 .

[0076] In step S43, the slump of the high-fluidity concrete is not less than 160 mm.

[0077] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A Rayleigh surface wave detection method for steel-concrete interface defects, characterized in that: The following steps are involved: S1: According to the parameters of the target to be measured, the center frequency f0 and the incident angle θ of the air-coupled probe are determined so that the air-coupled probe forms a Rayleigh surface wave in the target to be measured; S2: Select an air-coupled probe that matches the center frequency f0 as the excitation probe and the receiving probe, build a Rayleigh surface wave detection system, and calibrate the propagation velocity v and attenuation coefficient α of the Rayleigh surface wave for the target to be measured; S3: From one side of the steel plate, the Rayleigh surface wave detection system is used to scan and detect the target; if there is a defect, the defect position and lateral size are determined.

2. The Rayleigh surface wave detection method for steel-concrete interface defects according to claim 1 is characterized in that: In step S1: The parameters of the measured target include: the thickness of the steel h s , the thickness of the concrete slab h c , the density of steel ρ s , the density of the concrete slab ρ c , elastic modulus E of steel s , the elastic modulus E of the concrete slab c , Poisson's ratio of steel μ s , Poisson's ratio μ of the concrete slab c , air density ρ a and the air sound speed c a ; Based on the circulant matrix algorithm and spring model, the phase velocity dispersion curve of ultrasonic guided waves in a two-layer medium structure such as a steel and concrete composite structure is calculated, and the phase velocity c of the Rayleigh surface wave is extracted. R ; Determine the center frequency f0 of the air-coupled probe and quantitatively calculate the incident angle θ according to Snell's law: Where: c a is the air sound speed, c R is the phase velocity of the Rayleigh surface wave.

3. The Rayleigh surface wave detection method for steel-concrete interface defects according to claim 1 is characterized in that: In step S2, the process of calibrating the propagation velocity v and attenuation coefficient α of the Rayleigh surface wave for the measured target specifically includes: turning on the power supply, adjusting the excitation unit voltage and the gain of the signal amplifier, debugging the Rayleigh surface wave signal until a signal with a high signal-to-noise ratio is obtained, and automatically calibrating the propagation velocity v and attenuation coefficient α of the Rayleigh surface wave using the embedded software in the data processing unit: Where: L i represents the propagation distance at the i-th measurement line, t i represents the propagation time at the i-th survey line, A i0 represents the initial energy of the Rayleigh surface wave at the i-th line, A i represents the Rayleigh surface wave propagation L at the i-th line i The energy after the measurement, i = 1, 2, 3...N represents the number of the measurement line on the measured target; the larger the value of N is, the more accurate the Rayleigh surface wave propagation velocity v and the attenuation coefficient α are, and N is greater than or equal to 5.

4. The Rayleigh surface wave detection method for steel-concrete interface defects according to claim 3 is characterized in that: In step S2, the calculation formula of the signal-to-noise ratio SNR is: Among them: A S is the maximum amplitude of the Rayleigh surface wave signal, A N is the maximum amplitude of the noise in the received ultrasonic signal.

5. The Rayleigh surface wave detection method for steel-concrete interface defects according to claim 1, characterized in that: Step S3 specifically includes: fixing the distance between the excitation probe and the receiving probe, using the automatic detection module to drive the excitation probe and the receiving probe to perform automatic line scanning on the preset detection path on the steel plate side; synchronously collecting and storing the Rayleigh surface wave signal at each measuring point through the data acquisition unit; after compensating for its attenuation, performing line scanning imaging based on the waveform at each measuring point, and automatically judging whether there are defects on the steel-concrete interface.

6. The Rayleigh surface wave detection method for steel-concrete interface defects according to claim 5, characterized in that: In step S3, if there are defects, the automated detection module is used to set up an inspection path perpendicular to the original inspection path on the side of the steel plate for automated line scanning to mark the suspected defect area; then the automated detection module is used to adjust the probe spacing and scanning spacing, and fine scanning and imaging are performed along a Z shape in the suspected defect area to quantitatively determine the defect position and lateral size.

7. The Rayleigh surface wave detection method for steel-concrete interface defects according to claim 1, characterized in that: If a defect is detected in step S3, the defect is managed. The management process includes: S41: On the steel plate side near the center of the detected steel-concrete interface defect, a hole is drilled using an impact drill, and after cleaning the debris, the distribution characteristics of the defect are checked using endoscope imaging, and the lateral size of the defect is measured; S42: According to the endoscope inspection results, a plan for making the rough surface of concrete at the defect is designed, a grinder is used to make the rough surface, and dust in the defect is cleaned; S43: After pouring water into the defects through the holes, high-fluidity concrete is poured into the defects of the steel-concrete interface using a concrete pouring unit, and then curing is performed after sufficient vibration; S44: Clean the rust, dust, oil and other debris on the surface of the steel plate near the hole, use welding rods and electric welding machines to weld and fill the hole, and grind it flat after cooling; S45: After applying one coat of sealing primer on the repaired holes in the steel plate and its surroundings, apply three coats of high-strength, flexible, corrosion-resistant waterproof coating for waterproof and anti-corrosion treatment. The construction time interval between two adjacent coats is 20h to 22h.

8. A steel-concrete interface defect detection system, used for implementing the Rayleigh surface wave detection method for steel-concrete interface defects as claimed in any one of claims 1 to 7, characterized in that include: Signal excitation module, signal receiving and display module, automatic detection module; The signal excitation module includes: a power supply, an excitation unit, an excitation probe and a signal synchronization unit; The signal receiving and display module includes: a receiving probe, a signal amplifier, a data acquisition unit, a data processing unit and a display unit; The automatic detection module includes: a mechanical unit, an electronic control unit, a power unit and a sound absorption unit; The receiving probe and the exciting probe are both air-coupled probes.

9. A steel-concrete interface defect detection system according to claim 8, characterized in that It also includes a steel-concrete interface defect treatment module, which includes: an impact drill, an endoscope, a grinder, a concrete pouring unit, welding rods and an electric welder; the concrete pouring unit includes a motor, an electric controller, a mixer, a pressurizer, a pumping pipe and a vibrating rod.

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