Intelligent tunnel anchor cable damage detection and early warning system

Abstract

The invention discloses a tunnel anchor cable damage intelligent detection and early warning system, and belongs to the technical field of multi-source data detection, a multi-source data acquisition module detects the strain degree of an anchor cable through a wireless resistance strain gauge, and detects the wall thickness of the anchor cable through a wireless ultrasonic emission sheet; data collected by the wireless resistance strain gauge and the wireless ultrasonic transmitting sheet are transmitted to the wireless sensor, in the wireless sensor, received resistance change signals and ultrasonic signals are amplified and filtered, the signals are converted into digital signals through an analog-to-digital converter, the data are compressed, and the compressed data are transmitted to the wireless sensor. Then the data is transmitted to a data analysis and early warning module; and the data analysis and early warning module is used for predicting the residual life of the anchor cable and evaluating the risk level according to the processing results of the two different data, and carrying out early warning after a preset value is reached. The wireless anchor cable detection device is high in precision, low in cost and high in practicability and does not damage the anchor cable.

Description

Technical Field

[0001] The present invention belongs to the technical field of multi-source data detection, and in particular relates to an intelligent detection and early warning system for tunnel anchor cable damage. Background Art

[0002] Anchor cables have shown their unique advantages and value in many engineering fields due to their high prestress, strong adaptability, stability maintenance, long-term support effect, economic benefits and environmental friendliness. However, the mechanical properties and corrosion status of anchor cables are directly related to the safety and stability of anchoring projects, and pose a potential threat to the safety of life and property of the public. Therefore, the damage detection technology of anchor cables has become an urgent problem to be solved in the field of anchoring project safety assessment.

[0003] The strain and corrosion detection of tunnel anchor cables reflects the high attention paid to structural safety and durability. First, strain detection can monitor the stress changes of anchor cables under long-term loads in real time, predict potential structural damage, ensure the overall safety of tunnel structures, and avoid catastrophic consequences caused by the accumulation of small defects. Secondly, corrosion detection aims to reveal the degree of corrosion of anchor cables in harsh environments, warn of material degradation in advance, and take targeted maintenance measures to extend the service life of anchor cables, reduce life cycle costs, and maximize economic benefits. However, the existing detection technology has not fully considered the damage status of the detection device and the damage status of the anchor cables, and even non-destructive testing technology is mostly limited to the detection and evaluation of basic parameters such as the total length, free section length, anchor section length, and grouting quality of the anchor cables. At present, the strain and corrosion detection technology of anchor cables is still mostly at the traditional destructive or micro-destructive detection stage. In view of the various limitations of traditional anchor cable detection methods, it is particularly urgent to develop a wireless detection technology that is high-precision, low-cost, practical, and does not damage the anchor cables. This technology can not only achieve fast and convenient detection, but also does not cause significant damage to the anchor cable and detection system. It has become a key issue that needs to be solved in the field of anchor cable detection. In summary, this study aims to explore the safety performance of tunnel anchor cables to ensure that they meet the requirements of engineering safety and stability. Therefore, an intelligent detection and early warning system for tunnel anchor cable damage is proposed. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides an intelligent detection and early warning system for tunnel anchor cable damage, which has the advantages of high precision, low cost, strong practicality and wireless detection of anchor cables without damaging the anchor cables, thus solving the problems of the prior art.

[0005] The present invention is implemented as follows: a tunnel anchor cable damage intelligent detection and early warning system, comprising:

[0006] The multi-source data acquisition module detects the strain of the anchor cable through wireless resistance strain gauges and detects the wall thickness of the anchor cable through wireless ultrasonic transmitters. The wall thickness data is used to calculate the corrosion degree of the anchor cable.

[0007] The wireless transmission module transmits the data collected by the wireless resistance strain gauge and the wireless ultrasonic transmitter to the wireless sensor. In the wireless sensor, the received resistance change signal and ultrasonic signal are amplified and filtered, converted into digital signals through an analog-to-digital converter, and the data is compressed. Then, the data is transmitted to the data analysis and early warning module.

[0008] The data analysis and early warning module pre-processes the data of the wireless resistance strain gauge and the wireless ultrasonic transmitter, applies the machine learning algorithm to perform feature selection, and then optimizes the parameters through model training and cross-validation. It predicts the remaining life of the anchor cable and evaluates the risk level based on the processing results of the two different data, and issues an early warning when the preset value is reached.

[0009] As a preferred embodiment of the present invention, it also includes a smart snap ring for snapping onto the anchor cable, and each anchor cable is provided with three smart snap rings, which are respectively located at the anchoring section, the free section and the anchor head; the smart snap ring includes a ring body and a smart anchoring component, and the smart anchoring component can open the ring body for snap ring installation and adjust it according to the diameter of the anchor cable so that the ring body is in close contact with the anchor cable; the multi-source data acquisition module and the wireless transmission module are installed inside the smart snap ring.

[0010] As a preferred embodiment of the present invention, the tunnel anchor cable damage intelligent detection and early warning system also includes a power supply module, which is installed on the smart card ring. The power supply module includes a lithium battery and a magnetic resonance wireless charging unit. The magnetic resonance wireless charging unit includes a transmitting coil and a receiving coil. The lithium battery is electrically connected to the multi-source data acquisition module and / or the wireless transmission module. The transmitting coil is installed at the contact surface between the anchor cable and the outside world and is connected to an external power supply. The receiving coil is installed inside the smart card ring and is connected to the lithium battery.

[0011] As a preferred embodiment of the present invention, the multi-source data acquisition module includes:

[0012] The wireless resistance acquisition unit includes a wireless resistance strain gauge, which is installed inside the smart card ring. The surface of the wireless resistance strain gauge is in close contact with the surface of the anchor cable, and the strain of the anchor cable is detected in real time through the wireless resistance strain gauge;

[0013] The wireless ultrasonic acquisition unit non-invasively measures the wall thickness of the anchor cable through ultrasound, so that the data analysis and early warning module can compare the initial wall thickness with the current wall thickness and calculate the corrosion degree of the anchor cable.

[0014] As a preferred embodiment of the present invention, the wireless transmission module includes an amplifying and filtering unit, a data acquisition and processing unit, and a wireless transmission unit; the amplifying and filtering unit increases the voltage and ultrasonic signal strength through signal amplification, and removes noise through filtering; the data acquisition and processing unit converts the amplified voltage and ultrasonic signal into digital signals; the wireless transmission unit modulates the electrical signal into a form of transmission in the wireless channel, compresses the data, and transmits the data to the data analysis and early warning module.

[0015] As a preferred embodiment of the present invention, the data analysis and early warning module includes:

[0016] Data preprocessing unit: receives data from the wireless transmission module, and cleans, formats and normalizes the data;

[0017] Feature selection unit: using machine learning algorithms to select features that have a significant impact on the prediction of the remaining life of the anchor cable and the risk level assessment from the preprocessed data;

[0018] Model training and cross-validation unit: Build a prediction model based on the selected machine learning algorithm, divide the data set into training set and validation set through cross-validation method, train the model multiple times and evaluate its performance;

[0019] Prediction and evaluation unit: using the trained model, the remaining life of the anchor cable is predicted and the risk level is evaluated based on the processing results of two different data. The prediction results include the remaining service life of the anchor cable and the corresponding risk level;

[0020] Warning and notification unit: Based on the prediction and evaluation results, determine whether the remaining life of the anchor cable has reached the preset warning value. Once the warning value is reached or exceeded, the system will automatically trigger the warning mechanism and send a warning notification to relevant personnel via email, SMS or system prompts.

[0021] As a preferred embodiment of the present invention, the wireless resistance strain gauge and the wireless ultrasonic transmitting sheet are both fixedly connected to the inner surface of the smart card ring; and the wireless sensor is located in the middle of the wireless resistance strain gauge and the wireless ultrasonic transmitting sheet.

[0022] As a preferred embodiment of the present invention, the smart card ring includes:

[0023] The inner surface of the ring body is slidably connected with a first sliding sheet and a second sliding sheet, the first sliding sheet and the second sliding sheet are used to carry a wireless resistance strain gauge and a wireless ultrasonic transmitting sheet respectively, and the first sliding sheet and the first sliding sheet are fixedly connected with a first rack and a second rack on one side close to each other respectively, the first rack and the second rack are arranged opposite to each other, and both are arc-shaped racks;

[0024] The ring body is provided with a circular ring, a rotating shaft is rotatably connected in the circular ring, the outer end of the rotating shaft is fixedly connected with a rotating driving member, the inner end of the rotating shaft is an anti-slip end, a gear rod is sleeved on the rotating shaft, and the gear rod can engage with the first rack and the second rack.

[0025] As a preferred embodiment of the present invention, the rotary drive member is configured as a servo motor. When configured as a servo motor, the servo motor and the intelligent anchoring assembly as well as the data analysis and early warning module are signal-connected.

[0026] As a preferred embodiment of the present invention, the ring body includes a first half ring and a second half ring, one end of the first half ring and the second half ring are connected by a snap connection, and the other end is connected by an intelligent anchoring assembly; the circular ring is fixed on the first half ring, and a thread is provided on the rotating shaft, and a threaded hole is opened on the second half ring.

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

[0028] 1. The wireless resistance strain gauge and wireless ultrasonic transmitter of the present invention are designed to detect the health status of the anchor cable in a non-invasive manner. Through wireless data transmission technology, the data can be acquired remotely in real time, which improves the response speed and flexibility of the detection. The wireless detection system has high precision and high stability, and can accurately capture and record the subtle changes of the anchor cable to ensure the safety of the structure. At the same time, compared with the traditional wired detection system, it not only reduces the wiring cost, but also reduces the maintenance cost and prolongs the service life of the system.

[0029] 2. Using this system to detect anchor cable strain and corrosion not only achieves accurate and real-time assessment of the structural health status, but also significantly improves the efficiency and safety of detection through non-destructive detection methods, providing a solid technical guarantee for the long-term stability and safety of the structure. And intelligent detection and early warning of tunnel anchor cable damage based on two different data can improve accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a system block diagram of the intelligent detection and early warning system for tunnel anchor cable damage in Example 1 of the present invention;

[0031] Figure 2 is a system block diagram of the wireless transmission module in Embodiment 1 of the present invention;

[0032] Figure 3 This is a system block diagram of the data analysis and early warning module in Example 1 of the present invention;

[0033] Figure 4 This is a schematic diagram of the cross-sectional front view of the smart clip in Example 1 of the present invention;

[0034] Figure 5It is a schematic diagram of the side view structure of the wireless resistance strain gauge, the wireless sensor and the wireless ultrasonic transmitting sheet in Example 1 of the present invention;

[0035] Figure 6 It is a schematic diagram of the side view structure of the installation of the wireless resistance strain gauge and the wireless ultrasonic transmitting sheet in Example 2 of the present invention;

[0036] Figure 7 This is a schematic diagram of the main structure of the installation of the wireless resistance strain gauge and the wireless ultrasonic transmitting sheet in Example 2 of the present invention.

[0037] In the figure: 1. wireless resistance strain gauge; 2. wireless sensor; 21. amplification and filtering unit; 22. data acquisition and processing unit; 23. wireless transmission unit; 3. wireless ultrasonic transmitting sheet; 4. smart card ring; 41. ring body; 42. first sliding plate; 43. second sliding plate; 44. first rack; 45. second rack; 46. circular ring; 47. rotating shaft; 48. rotating drive member; 49. anti-slip end; 410. gear rod; 5. steel strand. DETAILED DESCRIPTION

[0038] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings.

[0039] The structure of the present invention is described in detail below in conjunction with the accompanying drawings.

[0040] Example 1

[0041] like Figures 1 to 5 As shown, an embodiment of the present invention provides an intelligent detection and early warning system for tunnel anchor cable damage, comprising:

[0042] The multi-source data acquisition module detects the strain degree of the anchor cable through the wireless resistance strain gauge 1 and detects the wall thickness of the anchor cable through the wireless ultrasonic transmitter 3, wherein the wall thickness data is used to calculate the corrosion degree of the anchor cable;

[0043] The wireless transmission module transmits the data collected by the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3 to the wireless sensor 2. In the wireless sensor 2, the received resistance change signal and ultrasonic signal are amplified and filtered, converted into digital signals through an analog-to-digital converter, and the data is compressed. Then, the data is transmitted to the data analysis and early warning module;

[0044] The data analysis and early warning module pre-processes the data of the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3, applies the machine learning algorithm to perform feature selection, and then optimizes the parameters through model training and cross-validation. It predicts the remaining life of the anchor cable and evaluates the risk level based on the processing results of the two different data, and issues an early warning when the preset value is reached.

[0045] Through the above settings, the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3 are designed to detect the health status of the anchor cable in a non-invasive manner. Through wireless data transmission technology, the data can be acquired remotely and instantly, which improves the response speed and flexibility of the detection. The wireless detection system has high precision and high stability, and can accurately capture and record subtle changes in the anchor cable to ensure structural safety. At the same time, compared with the traditional wired detection system, it not only reduces the wiring cost, but also reduces the maintenance cost and extends the service life of the system. Using this system to detect anchor cable strain and corrosion not only realizes the accurate and real-time assessment of the structural health status, but also significantly improves the efficiency and safety of the detection through non-destructive detection methods, providing a solid technical guarantee for the long-term stability and safety of the structure. And intelligent detection and early warning of tunnel anchor cable damage based on two different data can improve accuracy.

[0046] Exemplarily, the workflow of the intelligent detection and early warning system for tunnel anchor cable damage is as follows: Assume that in a tunnel project, an anchor cable is being inspected, as follows:

[0047] 1. Initial data collection: The wireless resistance strain gauge 1 is installed on the inner side of the smart card ring 4 and is in close contact with the anchor cable. When the anchor cable is in the initial state, the resistance value detected by the wireless resistance strain gauge 1 corresponds to the initial strain of the anchor cable. Assuming that the initial resistance value is R0 = 120Ω, according to the resistance strain coefficient k = 2.0 of the strain gauge (this is a characteristic parameter of the strain gauge, which indicates the resistance change rate caused by unit strain). When the anchor cable is subjected to a certain external load, the resistance value of the resistance strain gauge becomes R1 = 121Ω. According to the formula (where ε is the strain), the strain can be calculated This indicates that the anchor cable has undergone a certain degree of tensile strain.

[0048] At the same time, the wireless ultrasonic transmitter 3 detects the wall thickness of the anchor cable. Assuming that the initial wall thickness of the anchor cable is t0 = 10 mm, after a period of use, the wireless ultrasonic transmitter 3 detects the current wall thickness t1 = 9.8 mm. By formula (where C is the degree of corrosion), the degree of corrosion can be calculated

[0049]

[0050] 2. Data transmission and processing: The data collected by the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3 are transmitted to the wireless sensor 2 through the connecting line. In the wireless sensor 2, the amplification and filtering module amplifies and filters the received resistance change signal and ultrasonic signal. For example, after the resistance change signal is amplified, the voltage signal is amplified from the original weak 0.5mV to 5mV, so that it can be processed by the subsequent data acquisition and processing module. The processed signal is converted into a digital signal through an analog-to-digital converter, and the data is compressed, and then the data is transmitted to the data analysis and processing system through the wireless transmission module. Assume that during the data transmission process, due to certain electromagnetic interference in the tunnel, the signal-to-noise ratio (the ratio of signal to noise) of the original signal is 3:1. After being processed by the amplification and filtering module, the signal-to-noise ratio is increased to 20:1, which effectively improves the quality of the data and ensures that the data can be accurately transmitted to the data analysis and early warning module.

[0051] 3. Data analysis and early warning: After receiving the data, the data analysis and early warning module first performs preprocessing steps such as data cleaning and standardization. For example, the strain data collected at multiple time points are smoothed to remove outliers. Then key features are extracted, such as the strain change trend, corrosion rate, etc., and feature selection is performed using machine learning algorithms. Assume that through the analysis of historical data and model training, a prediction model based on a decision tree algorithm is established. The model predicts the remaining life and risk level of the anchor cable based on characteristics such as strain and corrosion degree. When the system analyzes the currently collected data (strain ε=0.00417, corrosion degree C=2%), combined with historical data and model parameters, it predicts that the remaining life of the anchor cable is 80% (assuming the total design life is 100%), and the risk level is a level III warning. Because although the anchor cable has certain strain and corrosion, it is still within a controllable range, and only general countermeasures need to be taken, such as increasing the monitoring frequency. According to the level III warning determined by the data analysis and processing system, the alarm system triggers the alarm to send out the corresponding alarm signal, notifying the tunnel maintenance personnel to pay attention to the situation of the anchor cable and handle it according to the prescribed level III warning response measures. Through the above data examples, we can clearly see the entire workflow of the intelligent detection and early warning system for tunnel anchor cable damage from data collection, transmission, processing to early warning, as well as the role played by each system component, so as to effectively realize the monitoring and early warning of the health status of the anchor cable and ensure the safety and stability of the tunnel structure.

[0052] Specifically, it also includes a smart clip 4, which is used to clip on the anchor cable, and each anchor cable is provided with three smart clips 4, which are respectively located at the anchor section, the free section, and the anchor head; the smart clip 4 includes a ring body 41 and a smart anchor assembly, and the smart anchor assembly can open the ring body 41 for clip installation and adjust according to the diameter of the anchor cable, so that the ring body 41 is in close contact with the anchor cable; the multi-source data acquisition module and the wireless transmission module are installed inside the smart clip 4. Specifically, the clip is made of PVDF, which is a plastic material with high chemical corrosion resistance, heat resistance and weather resistance.

[0053] Exemplarily, the intelligent anchoring assembly includes an electric adjustment device and a plurality of mechanical claws. The electric adjustment device is composed of a small motor, a transmission gear set and a screw nut mechanism. When the intelligent snap ring 4 needs to be installed, the motor is started, and the screw nut mechanism is driven to work through the transmission gear set, so that the mechanical claws are opened outward, thereby increasing the inner diameter of the ring body 41, so as to facilitate the snap ring to be put on the anchor cable. After the anchor cable is put on, the motor is reversed, and the mechanical claws shrink inward under the action of the screw nut mechanism until the anchor cable is tightly clamped. The inner side of the mechanical claw can be inlaid with elastic materials such as rubber or polyurethane, which can increase the friction between the anchor cable and ensure close contact, and avoid damage to the surface of the anchor cable. At the same time, the intelligent anchoring assembly is also equipped with a pressure sensor, which can monitor the contact pressure between the claw and the anchor cable in real time. When the pressure is not within the preset reasonable range (such as excessive pressure may damage the anchor cable, and too low pressure will cause loose contact and affect the accuracy of the detection data), the motor automatically performs fine adjustment to ensure that the ring body 41 and the anchor cable are always in the best close contact state.

[0054] Specifically, the intelligent detection and early warning system for tunnel anchor cable damage also includes a power supply module, which is installed on the smart card ring 4. The power supply module includes a lithium battery and a magnetic resonance wireless charging unit. The magnetic resonance wireless charging unit includes a transmitting coil and a receiving coil. The lithium battery is electrically connected to the multi-source data acquisition module and / or the wireless transmission module. The transmitting coil is installed at the contact surface between the anchor cable and the outside world and is connected to an external power supply. The receiving coil is installed inside the smart card ring 4 and is connected to the lithium battery. In the magnetic resonance wireless charging unit, electric energy is first input from an external power supply and converted into electromagnetic field energy through the transmitting coil. The receiving coil senses the electromagnetic field and converts it back into electric energy, thereby charging the lithium battery.

[0055] Magnetic resonance technology gives the system the ability to charge across space, enabling remote charging of lithium batteries and greatly expanding charging application scenarios. Secondly, the spatial adaptability of the system design eliminates the need for physical contact during the charging process, greatly improving the flexibility and convenience of charging. In addition, the two-way energy transmission function not only optimizes energy utilization, but also reflects the system's positive response to green energy.

[0056] The system combines the advanced sensing technology with the convenience of wireless transmission, providing a passive, low-power solution for anchor health monitoring, effectively reducing maintenance costs and improving the sustainability of monitoring.

[0057] When the wireless device is used to detect the health status of the anchor cable, the wireless sensor 2 consumes power when collecting and converting data. The lithium battery 7 provides the power demand for the wireless sensor 2. When the lithium battery 7 is low on power, the charging end uses the power supply to drive the transmitting coil 10 to generate an alternating magnetic field, and optimizes the energy transmission efficiency through resonant frequency matching. The receiving end captures the magnetic field energy through the receiving coil 4, generates current through electromagnetic induction, and then converts it into direct current through the rectifier circuit, and is distributed to the lithium battery 7 for storage by the control circuit. The lithium battery 7 is regularly replenished through the receiving coil 4, the transmitting coil 10 and the external power supply to ensure the normal operation of the wireless sensor 2.

[0058] Specifically, the multi-source data acquisition module includes:

[0059] The wireless resistance acquisition unit includes a wireless resistance strain gauge 1, which is installed inside the smart card ring 4. The surface of the wireless resistance strain gauge 1 is in close contact with the surface of the anchor cable, and the strain of the anchor cable is detected in real time through the wireless resistance strain gauge 1;

[0060] The wireless ultrasonic acquisition unit measures the wall thickness of the anchor cable non-invasively through ultrasound, so that the data analysis and early warning module can compare the initial wall thickness with the current wall thickness and calculate the corrosion degree of the anchor cable; or calculate the corrosion rate through the wall thickness of the previous test, the current wall thickness and the interval between two tests, and adjust the frequency of data acquisition according to the corrosion rate. For example, if the corrosion rate increases, the frequency of data acquisition will also increase, and vice versa.

[0061] Specifically, the wireless resistance acquisition system detects the strain of the anchor cable in real time through the wireless resistance strain gauge 1. The surface sensitive grid of the strain gauge is in contact with the surface of the anchor cable. When the anchor cable is strained (such as stretching, compression, etc.), the geometric shape of the strain gauge will change, and the resistance value of the strain gauge will change, thereby outputting a voltage signal corresponding to the change in resistance of the strain gauge. The wireless resistance strain gauge 1 is installed on the inner side of the smart card ring 4. The surface of the wireless resistance strain gauge 1 is in close contact with the surface of the anchor cable. The surface of the anchor cable is coated with polytetrafluoroethylene (PTFE) coating to protect the contact surface between the anchor cable and the strain gauge.

[0062] The wireless ultrasonic (corrosion) acquisition system detects the corrosion of the anchor cable in real time through the wireless ultrasonic transmitting piece 3, measures the wall thickness of the anchor cable non-invasively through ultrasound, compares the initial wall thickness with the current wall thickness, and calculates the corrosion degree of the anchor cable. The wireless ultrasonic transmitting piece 3 is installed on the inner side of the smart clip 4, and the surface of the wireless ultrasonic transmitting piece 3 is in close contact with the surface of the anchor cable. The surface of the anchor cable is coated with polytetrafluoroethylene (PTFE) coating to protect the contact surface between the anchor cable and the transmitting piece.

[0063] Specifically, the wireless transmission module includes an amplification and filtering unit 21, a data acquisition and processing unit 22, and a wireless transmission unit 23;

[0064] The amplification and filtering unit 21 increases the voltage and ultrasonic signal strength by signal amplification and removes noise by filtering;

[0065] The data acquisition and processing unit 22 converts the amplified voltage and ultrasonic signal into digital signals;

[0066] The wireless transmission unit 23 modulates the electrical signal into a form for transmission in a wireless channel, compresses the data, and transmits the data to the data analysis and early warning module.

[0067] Specifically, the data analysis and early warning module includes:

[0068] Data preprocessing unit: Receives data from the wireless transmission module, cleans, formats and normalizes the data; data cleaning includes removing invalid values, filling missing values ​​and processing outliers to ensure data quality. Formatting is to convert data into the format required for model training, such as converting a string to a numeric type or converting a timestamp to a date format. Normalization is to scale the data to the same range to eliminate the dimensional differences between different features and improve the training efficiency and accuracy of the model.

[0069] Feature selection unit: Use machine learning algorithms such as correlation analysis, recursive feature elimination (RFE), model-based feature selection, etc. to select features that have a significant impact on the prediction of the remaining life of the anchor cable and the risk level assessment from the preprocessed data. These features can better reflect the inherent laws and patterns of the data, thereby improving the accuracy of prediction and assessment.

[0070] Model training and cross-validation unit: Build a prediction model based on the selected machine learning algorithm (such as support vector machine, random forest, neural network, etc.), divide the data set into training set and validation set through cross-validation method, train the model multiple times and evaluate its performance. In the cross-validation process, continuously optimize the model parameters, such as learning rate, number of iterations, tree depth, etc., to improve the generalization ability and prediction accuracy of the model.

[0071] Prediction and evaluation unit: using the trained model, the processing results of two different data are used to predict the remaining service life of the anchor cable and evaluate the risk level. The prediction results include the remaining service life of the anchor cable and the corresponding risk level; the risk level is divided into three levels: level III warning, when changes in anchor cable stress and anchor cable corrosion are detected, general countermeasures are taken; level II warning, anchor cable breakage, prestress loss, support structure deformation, higher countermeasures are taken; level I warning, support node stress reaches the maximum, and severe countermeasures are taken.

[0072] Warning and notification unit: Based on the prediction and evaluation results, it is determined whether the remaining life of the anchor cable has reached the preset warning value. Once the warning value is reached or exceeded, the system will automatically trigger the warning mechanism and send a warning notification to relevant personnel through email, SMS or system prompts. The warning notification contains key information such as the anchor cable number, location, remaining life, risk level, etc., so that relevant personnel can take timely measures to deal with it.

[0073] Specifically, the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 are both fixedly connected to the inner surface of the smart card ring 4; the wireless sensor 2 is located in the middle of the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3. With this arrangement, the installation is relatively firm.

[0074] Example 2

[0075] Different from the first embodiment, the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 are not fixedly connected to the inner surface of the smart card ring 4, as follows:

[0076] The outer layer of the tunnel anchor cable is generally composed of 6 strands of steel strands 5. From the cross-section, the angle between adjacent steel strands 5 is 60°, and the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 need to fit with a certain steel strand 5 before they can be used. Therefore, when the ring body 41 is installed on the anchor cable, the ring body 41 must be installed firmly, and it cannot move along the axial direction of the anchor cable, nor can it rotate. Because when rotating, the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 will be separated from the steel strand 5, for example, moving to the gap position between the steel strands 5. Since the steel strand 5 is not a straight line, but is distributed in a twisted shape, the axial displacement of the ring body 41 will also cause the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 to be separated from the steel strand 5, for example, moving to the gap position between the steel strand 5. And because the diameters of different anchor cables are different, and the spacing between the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 is determined, it cannot be adapted to anchor cables of different diameters.

[0077] See also Figure 1-Figure 7 , the smart card ring 4 includes:

[0078] The inner surface of the ring body 41 is slidably connected with a first sliding sheet 42 and a second sliding sheet 43, the first sliding sheet 42 and the second sliding sheet 43 are used to carry the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 respectively, and the first sliding sheet 42 and the first sliding sheet 42 are fixedly connected with a first rack 44 and a second rack 45 on one side close to each other, respectively, the first rack 44 and the second rack 45 are arranged opposite to each other, and both are arc-shaped racks;

[0079] The ring body 41 is provided with a circular ring 46, in which a rotating shaft 47 is rotatably connected, the outer end of the rotating shaft 47 is fixedly connected to a rotating driving member 48, the inner end of the rotating shaft 47 is an anti-slip end 49, and a gear rod 410 is sleeved on the rotating shaft 47, and the gear rod 410 can be engaged with the first rack 44 and the second rack 45.

[0080] Through the above settings, the specific use includes the following steps:

[0081] First, the ring body 41 is clamped to the position to be detected of the anchor cable, and the ring body 41 is pre-installed by the intelligent anchoring assembly;

[0082] Second, slightly rotate the ring body 41 so that the anti-slip end 49 of the rotating shaft 47 is inserted into the gap between two adjacent steel strands 5;

[0083] Third, the rotating shaft 47 is driven to rotate by the rotating driving member 48, and the first rack 44 and the second rack 45 are moved by the gear rod 410, so that the first slide 42 and the second slide 43 are moved away from each other until the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 are respectively attached to the two adjacent steel strands 5;

[0084] Fourthly, the ring body 41 is locked by the intelligent anchoring assembly so that the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 are firmly attached to the steel strand 5 .

[0085] Through this arrangement, on the one hand, the positions of the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 can be adjusted to adapt to cables of different diameters; on the other hand, the anti-slip end of the rotating shaft 47 is inserted into the gap between two adjacent steel strands 5 and pressed against the steel strands 5, which can prevent the ring body 41 from axial movement and rotation, thereby improving the firmness of the installation, making the position of each detection the same, and improving the accuracy of the detection.

[0086] It should be noted that the intelligent anchoring assembly has two states, the first being a pre-installation state, in which it is not tightened, and the second being a tightened installation state, in which it is fully tightened at the end.

[0087] Furthermore, the rotary drive member 48 can be set as a manual knob or as a servo motor. When set as a servo motor, the servo motor and the intelligent anchoring component and the data analysis and early warning module are connected by signal. The specific usage method is that the intelligent anchoring component pre-installs the ring body 41 on the anchor cable, and then notifies the servo motor to drive the rotating shaft 47 to rotate, adjust the position of the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting piece 3, so that the two are respectively fitted with two adjacent steel strands 5. During this process, the wireless ultrasonic transmitting piece 3 measures the distance between the wireless ultrasonic transmitting piece 3 and the steel strand 5, so as to determine whether the wireless ultrasonic transmitting piece 3 is fitted with the steel strand 5 through the data analysis and early warning module. When the wireless ultrasonic transmitting piece 3 is fitted with the steel strand 5, the intelligent anchoring component is notified to lock the ring body 41.

[0088] It should be noted that the ring body 41 can be set as an integral type (for example, made of plastic, which can be deformed and put on the anchor cable), or it can be composed of two half rings. When it is set as two half rings, for example, the first half ring and the second half ring, the following settings can be made: one end of the first half ring and the second half ring are connected by snap connection, and the other end is connected by an intelligent anchoring assembly. At this time, the ring 46 is fixed on the first half ring, and the rotating shaft 47 is provided with a thread, and the second half ring is provided with a threaded hole. When the device is not installed (for example, during transportation), the outer surface of the second half ring is fitted with the inner surface of the first half ring, and the threaded section of the rotating shaft is connected to the threaded hole, so that the two half rings are connected together, which is convenient for transportation and saves space. At the same time, the second half ring can protect the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3 on the first slide 42 and the second slide 43 to prevent foreign objects from colliding with the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting sheet 3.

[0089] Working principle of the present invention:

[0090] The multi-source data acquisition module detects the strain degree of the anchor cable through the wireless resistance strain gauge 1 and detects the wall thickness of the anchor cable through the wireless ultrasonic transmitter 3, wherein the wall thickness data is used to calculate the corrosion degree of the anchor cable;

[0091] The wireless transmission module transmits the data collected by the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3 to the wireless sensor 2. In the wireless sensor 2, the received resistance change signal and ultrasonic signal are amplified and filtered, converted into digital signals through an analog-to-digital converter, and the data is compressed. Then, the data is transmitted to the data analysis and early warning module;

[0092] The data analysis and early warning module preprocesses the data of the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3, applies the machine learning algorithm to perform feature selection, and then optimizes the parameters through model training and cross-validation. It predicts the remaining life of the anchor cable and evaluates the risk level based on the processing results of the two different data, and issues an early warning when the preset value is reached.

[0093] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0094] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An intelligent detection and early warning system for tunnel anchor cable damage, including a multi-source data acquisition module, characterized in that: A multi-source data acquisition module detects the strain degree of the anchor cable through a wireless resistance strain gauge (1) and detects the wall thickness of the anchor cable through a wireless ultrasonic transmitting piece (3), wherein the wall thickness data is used to calculate the corrosion degree of the anchor cable; A wireless transmission module transmits data collected by a wireless resistance strain gauge (1) and a wireless ultrasonic transmitter (3) to a wireless sensor (2). In the wireless sensor (2), the received resistance change signal and ultrasonic signal are amplified and filtered, converted into digital signals through an analog-to-digital converter, and the data is compressed. The data is then transmitted to a data analysis and early warning module. The data analysis and early warning module pre-processes the data of the wireless resistance strain gauge (1) and the wireless ultrasonic transmitter (3), applies a machine learning algorithm to perform feature selection, and then optimizes parameters through model training and cross-validation. The remaining life of the anchor cable is predicted and the risk level is evaluated based on the processing results of the two different data, and an early warning is issued after reaching a preset value.

2. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 1, characterized in that: It also includes a smart clip (4) for clipping onto the anchor cable, and each anchor cable is provided with three smart clips (4), which are respectively located at the anchoring section, the free section, and the anchor head; The smart clip ring (4) comprises a ring body (41) and a smart anchoring assembly, wherein the smart anchoring assembly can open the ring body (41) to install the clip ring and adjust the ring body (41) according to the diameter of the anchor cable so that the ring body (41) is in close contact with the anchor cable; The multi-source data acquisition module and the wireless transmission module are installed inside the smart card ring (4).

3. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 2, characterized in that: The tunnel anchor cable damage intelligent detection and early warning system also includes a power supply module, which is installed on the intelligent card ring (4). The power supply module includes a lithium battery and a magnetic resonance wireless charging unit. The magnetic resonance wireless charging unit includes a transmitting coil and a receiving coil. The lithium battery is electrically connected to the multi-source data acquisition module and / or the wireless transmission module. The transmitting coil is installed at the contact surface between the anchor cable and the outside world and is connected to an external power supply. The receiving coil is installed inside the intelligent card ring (4) and is connected to the lithium battery.

4. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 1, characterized in that: The multi-source data acquisition module comprises: A wireless resistance acquisition unit comprises a wireless resistance strain gauge (1), wherein the wireless resistance strain gauge (1) is installed inside the smart card ring (4), the surface of the wireless resistance strain gauge (1) is in close contact with the surface of the anchor cable, and the strain of the anchor cable is detected in real time through the wireless resistance strain gauge (1); The wireless ultrasonic acquisition unit non-invasively measures the wall thickness of the anchor cable through ultrasound, so that the data analysis and early warning module can compare the initial wall thickness with the current wall thickness and calculate the corrosion degree of the anchor cable.

5. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 1, characterized in that: The wireless transmission module comprises an amplification and filtering unit (21), a data acquisition and processing unit (22), and a wireless transmission unit (23); The amplification and filtering unit (21) increases the voltage and ultrasonic signal strength by signal amplification and removes noise by filtering; The data acquisition and processing unit (22) converts the amplified voltage and ultrasonic signal into digital signals; The wireless transmission unit (23) modulates the electrical signal into a form for transmission in a wireless channel, compresses the data, and transmits the data to the data analysis and early warning module.

6. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 1, characterized in that: The data analysis and early warning module includes: Data preprocessing unit: receives data from the wireless transmission module, and cleans, formats and normalizes the data; Feature selection unit: using machine learning algorithms to select features that have a significant impact on the prediction of the remaining life of the anchor cable and the risk level assessment from the preprocessed data; Model training and cross-validation unit: Build a prediction model based on the selected machine learning algorithm, divide the data set into training set and validation set through cross-validation method, train the model multiple times and evaluate its performance; Prediction and evaluation unit: using the trained model, the remaining life of the anchor cable is predicted and the risk level is evaluated based on the processing results of two different data. The prediction results include the remaining service life of the anchor cable and the corresponding risk level; Warning and notification unit: Based on the prediction and evaluation results, determine whether the remaining life of the anchor cable has reached the preset warning value. Once the warning value is reached or exceeded, the system will automatically trigger the warning mechanism and send a warning notification to relevant personnel via email, SMS or system prompts.

7. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 2, characterized in that: The wireless resistance strain gauge (1) and the wireless ultrasonic transmitting sheet (3) are both fixedly connected to the inner surface of the smart card ring (4); the wireless sensor (2) is located in the middle of the wireless resistance strain gauge (1) and the wireless ultrasonic transmitting sheet (3).

8. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 2, characterized in that: The smart card ring (4) comprises: The inner surface of the ring body (41) is slidably connected with a first sliding sheet (42) and a second sliding sheet (43), the first sliding sheet (42) and the second sliding sheet (43) are respectively used to carry a wireless resistance strain gauge (1) and a wireless ultrasonic transmitting sheet (3), and the first sliding sheet (42) and the second sliding sheet (43) are respectively fixedly connected with a first rack (44) and a second rack (45) on the side where the first sliding sheet (42) and the second sliding sheet (42) are close to each other, and the first rack (44) and the second rack (45) are arranged opposite to each other and are both arc-shaped racks; The ring body (41) is provided with a circular ring (46), a rotating shaft (47) is rotatably connected in the circular ring (46), a rotating drive member (48) is fixedly connected to the outer end of the rotating shaft (47), an anti-slip end (49) is provided at the inner end of the rotating shaft (47), a gear rod (410) is sleeved on the rotating shaft (47), and the gear rod (410) can mesh with the first rack (44) and the second rack (45).

9. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 8, characterized in that: The rotary drive member (48) is configured as a servo motor. When configured as a servo motor, the servo motor is connected to the intelligent anchoring assembly and the data analysis and warning module signal.

10. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 8 or 9, characterized in that: The ring body comprises a first half ring and a second half ring, one end of the first half ring and the second half ring are connected by a snap connection, and the other end is connected by an intelligent anchoring assembly; The circular ring (46) is fixed on the first half ring, and the rotating shaft (47) is provided with a thread, while the second half ring is provided with a threaded hole.

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