An intelligent detection and early warning system for tunnel cable damage

Abstract

The present invention discloses an intelligent detection and early warning system for tunnel anchor cable damage, belonging to the technical field of multi-source data detection. The multi-source data acquisition module detects the strain degree of the anchor cable through a wireless resistance strain gauge and detects the wall thickness of the anchor cable through a wireless ultrasonic transmitter; the data collected by the wireless resistance strain gauge and the wireless ultrasonic transmitter are transmitted to a 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, and then the data is transmitted to the data analysis and early warning module; the data analysis and early warning module predicts the remaining life of the anchor cable and evaluates the risk level according to the processing results of the two different types of data, and issues an early warning after reaching the preset value. The invention can wirelessly detect the anchor cable with high precision, low cost, strong practicability and without damaging the anchor cable.

Description

Technical Field

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

[0002] Due to its advantages such as high prestress, strong adaptability, stability maintenance, long-term support effect, economic benefits, and environmental friendliness, the anchor cable has demonstrated its unique advantages and value in many engineering fields. However, the mechanical properties and corrosion conditions of the anchor cable are directly related to the safety and stability of the anchoring project, and at the same time pose a potential threat to the life and property safety of the public. Therefore, the damage detection technology of the anchor cable has become an urgent problem to be solved in the field of safety assessment of the anchoring project.

[0003] Detecting the strain and corrosion conditions of tunnel anchor cables reflects a high degree of attention to the structural safety and durability. First of all, strain detection can monitor the stress changes of the anchor cable under long-term loads in real time, predict potential structural damage, ensure the overall safety of the tunnel structure, and avoid catastrophic consequences caused by the accumulation of minor defects. Secondly, corrosion detection aims to reveal the corrosion degree of the anchor cable in a harsh environment, give early warning of material degradation, so as to take targeted maintenance measures, extend the service life of the anchor cable, reduce the life cycle cost, and maximize economic benefits. However, the existing detection technologies have not fully considered the damage conditions of the detection devices and the damage conditions of the anchor cables, and even non-destructive detection technologies are mostly limited to the detection and evaluation of basic parameters such as the total length, free section length, anchorage section length, and grouting quality of the anchor cables. At present, the strain and corrosion detection technologies of anchor cables still mostly stay in the traditional destructive or slightly destructive detection stage. In view of the various limitations of the traditional anchor cable detection methods, it is particularly urgent to develop a wireless detection technology with high precision, low cost, strong practicability and no damage to the anchor cable. This technology can not only achieve fast and convenient detection, but also will not cause significant damage to the anchor cable and the detection system, and has become a key problem to be solved in the field of anchor cable detection. To sum up, this research 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] Aiming at 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 being able to wirelessly detect the anchor cable with high precision, low cost, strong practicability and no damage to the anchor cable, and solves the problems of the prior art.

[0005] The present invention is implemented as follows. An intelligent detection and early warning system for tunnel anchor cable damage includes:

[0006] The multi-source data acquisition module detects the strain degree of the anchor cable through wireless resistance strain gauges and detects the wall thickness of the anchor cable through wireless ultrasonic emission sheets, where 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 gauges and wireless ultrasonic emission sheets 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, and then the data is transmitted to the data analysis and early warning module;

[0008] The data analysis and early warning module preprocesses the data of the wireless resistance strain gauges and wireless ultrasonic emission sheets, applies machine learning algorithms for feature selection, optimizes the parameters through model training and cross-validation, predicts the remaining life of the anchor cable and evaluates the risk level according to the processing results of the two different data, and issues an early warning after reaching the preset value.

[0009] Preferably, as the present invention, it further includes intelligent snap rings, which are used to be clamped on the anchor cable, and three intelligent snap rings are provided for each anchor cable, which are respectively located at the anchorage section, the free section, and the anchor head; the intelligent snap ring includes a ring body and an intelligent anchoring component, and the intelligent anchoring component can open the ring body for snap ring installation and adjust 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 intelligent snap ring.

[0010] Preferably, as the present invention, the tunnel anchor cable damage intelligent detection and early warning system further includes a power supply module, the power supply module is installed on the intelligent snap 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 intelligent snap ring, and the receiving coil is connected to the lithium battery.

[0011] Preferably, as the present invention, the multi-source data acquisition module includes:

[0012] A wireless resistance acquisition unit, including a wireless resistance strain gauge, the wireless resistance strain gauge is installed on the inner side of the intelligent snap 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] A wireless ultrasonic acquisition unit non-invasively measures the wall thickness of the anchor cable through ultrasonic waves, so that the data analysis and early warning module can compare the initial wall thickness and the current wall thickness and calculate the corrosion degree of the anchor cable.

[0014] Preferably, the wireless transmission module includes an amplification and filtering unit, a data acquisition and processing unit, and a wireless transmission unit. The amplification and filtering unit improves the voltage and ultrasonic signal intensity through signal amplification and removes noise through filtering. The data acquisition and processing unit converts the amplified voltage and ultrasonic signals into digital signals. The wireless transmission unit modulates the electrical signals into a form transmitted in the wireless channel, compresses the data, and transmits the data to the data analysis and early warning module.

[0015] Preferably, the data analysis and early warning module includes:

[0016] Data preprocessing unit: Receives the data from the wireless transmission module, and performs cleaning, formatting, and normalization processing on the data.

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

[0018] Model training and cross-validation unit: Constructs a prediction model according to the selected machine learning algorithm. By means of cross-validation, divides the data set into a training set and a validation set, trains the model multiple times and evaluates its performance.

[0019] Prediction and evaluation unit: Utilizes the trained model to predict the remaining life of the anchor cable and evaluate the risk level for the processing results of two different types of data. The prediction results include the remaining service life of the anchor cable and the corresponding risk level.

[0020] Early warning and notification unit: According to the results of the prediction and evaluation, determines whether the remaining life of the anchor cable reaches the preset early warning value. Once it reaches or exceeds the early warning value, the system will automatically trigger the early warning mechanism and send an early warning notification to relevant personnel via email, text message, or system prompt.

[0021] Preferably, the wireless resistance strain gauge and the wireless ultrasonic transmitter are both fixedly connected to the inner surface of the intelligent snap ring. The wireless sensor is located in the middle of the wireless resistance strain gauge and the wireless ultrasonic transmitter.

[0022] Preferably, the intelligent snap ring includes:

[0023] A first sliding piece and a second sliding piece are slidably connected to the inner surface of the ring body. The first sliding piece and the second sliding piece are respectively used to carry the wireless resistance strain gauge and the wireless ultrasonic transmitter. One side of the first sliding piece and the first sliding piece that are close to each other are respectively fixedly connected with a first rack and a second rack. The first rack and the second rack are arranged oppositely and are both arc-shaped racks.

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

[0025] Preferably, the rotation driving member is set as a servo motor. When it is set as a servo motor, the servo motor is signal-connected to the intelligent anchoring component and the data analysis and early warning module.

[0026] Preferably, the ring body includes a first half-ring and a second half-ring. One ends of the first half-ring and the second half-ring are connected by clamping, and the other ends are connected by an intelligent anchoring component; the circular ring is fixed on the first half-ring, and a thread is provided on the rotating shaft, and a threaded hole is provided on the second half-ring.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. The wireless resistance strain gauge and the wireless ultrasonic transmitting sheet of the present invention are non-invasively designed to detect the health status of the anchor cable. Through the wireless data transmission technology, the instant remote acquisition of data is realized, the response speed and flexibility of the detection are improved. The wireless detection system has high precision and high stability, can accurately capture and record the subtle changes of the anchor cable, and ensure the 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.

[0029] 2. Using this system for anchor cable strain and corrosion detection, not only realizes the accurate and real-time evaluation of the structural health status, but also significantly improves the detection efficiency and safety through non-destructive detection means, providing a solid technical guarantee for the long-term stability and safety of the structure. And according to two different kinds of data, the intelligent detection and early warning of the tunnel anchor cable damage can be carried out, which can improve the accuracy. Description of the Drawings

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

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

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

[0033] Figure 4 It is the schematic cross-sectional front view structure diagram of the intelligent snap ring in Embodiment 1 of the present invention;

[0034] Figure 5Schematic side view structure of the wireless resistive strain gauge, wireless sensor, and wireless ultrasonic transmitter in Embodiment 1 of the present invention;

[0035] Figure 6 Schematic side view structure of the installation of the wireless resistive strain gauge and wireless ultrasonic transmitter in Embodiment 2 of the present invention;

[0036] Figure 7 Schematic front view structure of the installation of the wireless resistive strain gauge and wireless ultrasonic transmitter in Embodiment 2 of the present invention.

[0037] In the figure: 1, wireless resistive strain gauge; 2, wireless sensor; 21, amplification and filtering unit; 22, data acquisition and processing unit; 23, wireless transmission unit; 3, wireless ultrasonic transmitter; 4, smart card ring; 41, ring body; 42, first sliding piece; 43, second sliding piece; 44, first rack; 45, second rack; 46, circular ring; 47, rotating shaft; 48, rotation driving member; 49, anti-slip end; 410, toothed rod; 5, steel strand. Detailed implementation manners

[0038] To further understand the content, features, and effects of the present invention, the following embodiments are exemplified and described in detail in conjunction with the accompanying drawings.

[0039] The structure of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] Embodiment 1

[0041] As Figures 1 to 5 shown, a tunnel anchor cable damage intelligent detection and early warning system provided by an embodiment of the present invention includes:

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

[0043] A wireless transmission module that transmits the data collected by the wireless resistive 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, and then the data is transmitted to the data analysis and early warning module;

[0044] A data analysis and early warning module that preprocesses the data of the wireless resistive strain gauge 1 and the wireless ultrasonic transmitter 3, applies machine learning algorithms for feature selection, optimizes the parameters through model training and cross-validation, predicts the remaining life of the anchor cable and evaluates the risk level according to the processing results of the two different data, and gives an early warning after reaching the preset value.

[0045] With the above settings, the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3 are non-invasively designed to detect the health status of the cable anchor. Through wireless data transmission technology, real-time remote acquisition of data is achieved, improving the response speed and flexibility of detection. The wireless detection system has high precision and high stability, can accurately capture and record the subtle changes of the cable anchor, and 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 for cable anchor strain and corrosion detection not only realizes the accurate and real-time assessment of the structural health status, but also significantly improves the detection efficiency and safety through non-destructive detection means, providing a solid technical guarantee for the long-term stability and safety of the structure. And intelligent detection and early warning of tunnel cable anchor damage based on two different types of data can improve the accuracy.

[0046] Exemplarily, the working process of the intelligent detection and early warning system for tunnel cable anchor damage is as follows: Suppose in a certain tunnel project, a cable anchor is being detected, specifically as follows:

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

[0048] At the same time, the wireless ultrasonic transmitter 3 detects the wall thickness of the cable anchor. Suppose the initial wall thickness of the cable anchor is t0 = 10 mm. After a period of use, the wireless ultrasonic transmitter 3 detects that the current wall thickness is t1 = 9.8 mm. Through the formula (where C is the corrosion degree), the corrosion degree 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 connecting wires. 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 0.5 mV to 5 mV, which is convenient for the subsequent data acquisition and processing module to process. 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. Suppose 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, effectively improving the quality of the data and ensuring that the data can be accurately transmitted to the data analysis and warning module.

[0051] 3. Data Analysis and Warning: After receiving the data, the data analysis and warning module first performs preprocessing steps such as data cleaning and standardization. For example, the strain data at multiple time points collected is smoothed to remove outliers. Then key features are extracted, such as the change trend of strain, corrosion rate, etc., and machine learning algorithms are used for feature selection. Suppose that through the analysis of historical data and model training, a prediction model based on the decision tree algorithm is established. This model predicts the remaining life and risk level of the anchor cable according to features 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 is predicted that the remaining life of this anchor cable is still 80% (assuming the total design life is 100%), and the risk level is a level III warning. Because although the anchor cable has a certain amount of strain and corrosion, it is still within the controllable range, and only general countermeasures need to be taken, such as increasing the monitoring frequency. The alarm system triggers the alarm to send out corresponding alarm signals according to the level III warning determined by the data analysis and processing system, notifies the tunnel maintenance personnel to pay attention to the situation of this anchor cable, and processes it according to the level III warning countermeasures specified. Through the above example with data, it can be clearly seen the entire workflow of the intelligent detection and warning system for tunnel anchor cable damage from data collection, transmission, processing to warning, as well as the roles played by each system component, thus effectively realizing the monitoring and warning of the health status of the anchor cable and ensuring the safety and stability of the tunnel structure.

[0052] Specifically, it further includes an intelligent snap ring 4 for clamping onto the cable anchor, and three intelligent snap rings 4 are provided for each cable anchor, which are respectively located at the anchorage section, the free section, and the anchor head; the intelligent snap ring 4 includes a ring body 41 and an intelligent anchoring assembly, and the intelligent anchoring assembly can open the ring body 41 for snap ring installation and adjust according to the diameter of the cable anchor to make the ring body 41 in close contact with the cable anchor; the multi-source data acquisition module and the wireless transmission module are installed inside the intelligent snap ring 4. Specifically, the snap ring is made of PVDF material, and this plastic material has 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 consists of a small motor, a transmission gear set, and a lead screw nut mechanism. When installing the intelligent snap ring 4, the motor is started, and the lead screw nut mechanism is driven to work through the transmission gear set, causing the mechanical claws to open outward, thereby increasing the inner diameter of the ring body 41 to facilitate slipping the snap ring onto the cable anchor. After slipping the cable anchor on, the motor rotates in reverse, and the mechanical claws contract inward under the action of the lead screw nut mechanism until they tightly grip the cable anchor. Elastic materials such as rubber or polyurethane can be inlaid on the inner side of the mechanical claws, which can not only increase the friction with the cable anchor to ensure close contact but also avoid damaging the surface of the cable anchor. At the same time, the intelligent anchoring assembly is also equipped with a pressure sensor that can continuously monitor the contact pressure between the claws and the cable anchor. When the pressure is not within the preset reasonable range (for example, excessive pressure may damage the cable anchor, and too little pressure may result in insufficient contact and affect the accuracy of detection data), the motor automatically makes fine adjustments to ensure that the ring body 41 and the cable anchor are always in the best close contact state.

[0054] Specifically, the intelligent detection and early warning system for tunnel cable anchor damage further includes a power supply module, and the power supply module is installed on the intelligent snap 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 cable anchor and the outside and is connected to an external power supply. The receiving coil is installed inside the intelligent snap ring 4, and the receiving coil is connected to the lithium battery. In the magnetic resonance wireless charging unit, electrical energy is first input from an external power supply, converted into electromagnetic field energy through the transmitting coil, and the receiving coil senses the electromagnetic field and converts it back into electrical energy to charge the lithium battery.

[0055] Magnetic resonance technology endows the system with the ability to charge across space, realizing remote charging of lithium batteries and greatly expanding the charging application scenarios; secondly, the spatial adaptability in the system design enables the charging process to be without physical contact, greatly enhancing the flexibility and convenience of charging; in addition, the bi-directional 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 condition of the anchor cable in real time through the wireless ultrasonic transmitting sheet 3, non-invasively measures the wall thickness of the anchor cable by ultrasonic waves, compares the initial wall thickness with the current wall thickness, and calculates the corrosion degree of the anchor cable. The wireless ultrasonic transmitting sheet 3 is installed inside the intelligent snap ring 4, and the surface of the wireless ultrasonic transmitting sheet 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 sheet.

[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 improves the voltage and ultrasonic signal intensity through signal amplification and removes noise through filtering;

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

[0066] The wireless transmission unit 23 modulates the electrical signal into a form transmitted in the 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 the data from the wireless transmission module, and performs cleaning, formatting, and normalization processing on the data; Data cleaning includes removing invalid values, filling in missing values, and processing outliers to ensure data quality. Formatting is to convert the data into the format required for model training, such as converting strings to numerical types, or converting timestamps to date formats. Normalization processing is to scale the data to the same range to eliminate the dimensionality differences between different features and improve the training efficiency and accuracy of the model.

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

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

[0071] Prediction and evaluation unit: Using the trained model, predict the remaining life of the anchor cable and evaluate the risk level for the processing results of two different types of data. The prediction results include the remaining service life of the anchor cable and the corresponding risk level. The risk levels are divided into three levels. For level III warning, when it is detected that the stress of the anchor cable changes and the anchor cable is corroded, general countermeasures are taken. For level II warning, when the anchor cable breaks, prestress loss occurs, and the supporting structure deforms, higher countermeasures are taken. For level I warning, when the stress of the supporting node reaches the maximum, severe countermeasures are taken.

[0072] Warning and notification unit: According to the prediction and evaluation results, determine whether the remaining life of the anchor cable reaches the preset warning value. Once it reaches or exceeds the warning value, the system will automatically trigger the warning mechanism and send a warning notification to relevant personnel via email, text message, or system prompt. The warning notification contains key information such as the number, location, remaining life, and risk level of the anchor cable, so that relevant personnel can take measures to deal with it in a timely manner.

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

[0074] Embodiment 2

[0075] Different from Embodiment 1, the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3 are not fixedly connected to the inner surface of the intelligent snap ring 4, specifically as follows:

[0076] The outer layer of the tunnel anchor cable is generally composed of 6 strands of steel strands 5. From its cross-section, the included angle between adjacent steel strands 5 is 60°. The wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3 both need to be attached to a certain steel strand 5 to be used. Therefore, when installing the ring body 41 on the anchor cable, the ring body 41 must be installed firmly, neither moving along the axial direction of the anchor cable nor rotating. Because when rotating, both the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3 will be detached from the steel strand 5, for example, moving to the gap position between the steel strands 5. Since the steel strands 5 are not straight but 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 transmitter 3 to be detached from the steel strand 5, for example, moving to the gap position between the steel strands 5. And because the diameters of different anchor cables are different, and the distance between the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3 is determined, it cannot be adapted to anchor cables with different diameters.

[0077] Refer to Figures 1 - 7 The intelligent snap ring 4 includes:

[0078] The inner surface of the ring body 41 is slidably connected with a first sliding piece 42 and a second sliding piece 43. The first sliding piece 42 and the second sliding piece 43 are respectively used for carrying the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting piece 3. One side of the first sliding piece 42 and the first sliding piece 42 close to each other are respectively fixedly connected with a first rack 44 and a second rack 45. The first rack 44 and the second rack 45 are arranged oppositely and are both arc-shaped racks.

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

[0080] With the above settings, in specific use, it includes the following steps:

[0081] First, the ring body 41 is clamped at the position to be detected of the anchor cable, and the ring body 41 is pre-installed through the intelligent anchoring component.

[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, drive the rotating shaft 47 to rotate through the rotation driving part 48, and drive the first rack 44 and the second rack 45 through the toothed rod 410, so that the first sliding piece 42 and the second sliding piece 43 move away from each other until the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting piece 3 are respectively attached to two adjacent steel strands 5.

[0084] Fourth, lock the ring body 41 through the intelligent anchoring component, so that the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting piece 3 are firmly attached to the steel strand 5.

[0085] With this setting, on the one hand, the positions of the wireless resistance strain gauge 1 and the wireless ultrasonic transmitting piece 3 can be adjusted to adapt to cables with 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 is pressed against the steel strand 5, which can prevent the ring body 41 from axially moving and rotating, improve the firmness of installation, enable the detection position to be the same each time, and improve the detection accuracy.

[0086] It should be noted that the intelligent anchoring component has two states. The first is the pre-installation state, when it is not tightened, and the second is the tight installation state, when it is fully tightened finally.

[0087] Further, the rotation driving member 48 can be set as a manual knob or a servo motor. When it is set as a servo motor, the servo motor is signal-connected to the intelligent anchoring assembly and the data analysis and early warning module. The specific usage method is as follows: The intelligent anchoring assembly pre-installs the ring body 41 onto the anchor cable, and then notifies the servo motor to drive the rotating shaft 47 to rotate, adjusting the positions of the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3 so that they are respectively attached to two adjacent steel strands 5. During this process, the wireless ultrasonic transmitter 3 measures the distance between the wireless ultrasonic transmitter 3 and the steel strand 5, thereby judging whether the wireless ultrasonic transmitter 3 is attached to the steel strand 5 through the data analysis and early warning module. When the wireless ultrasonic transmitter 3 is attached to the steel strand 5, it notifies the intelligent anchoring assembly to lock the ring body 41.

[0088] It should be noted that the ring body 41 can be set as an integral body (for example, made of plastic and can be deformed to be sleeved 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 is connected by clamping, and the other end is connected by the intelligent anchoring assembly. At this time, the circular ring 46 is fixed on the first half-ring, and the rotating shaft 47 is provided with threads, while the second half-ring is provided with threaded holes. When the device is not installed (for example, during transportation), the outer surface of the second half-ring is attached to 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 transmitter 3 on the first sliding piece 42 and the second sliding piece 43, preventing foreign objects from colliding with the wireless resistance strain gauge 1 and the wireless ultrasonic transmitter 3.

[0089] The 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. 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, and 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 machine learning algorithms for feature selection, optimizes the parameters through model training and cross-validation, predicts the remaining life of the anchor cable and evaluates the risk level based on the processing results of the two different types of data, and issues an early warning after reaching the preset value.

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

[0094] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and 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: 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 transmitting sheet (3), wherein the wall thickness data is used to calculate the corrosion degree of the anchor cable; The wireless transmission module transmits the data collected by the wireless resistance strain gauge (1) and the wireless ultrasonic transmitting sheet (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, and then the data is transmitted to the data analysis and early warning module; The data analysis and early warning module preprocesses the data of the wireless resistance strain gauge (1) and the wireless ultrasonic transmitting sheet (3), applies machine learning algorithms for feature selection, optimizes the parameters through model training and cross-validation, predicts the remaining life of the anchor cable and evaluates the risk level according to the processing results of the two different data, and issues an early warning after reaching the preset value; It also includes an intelligent snap ring (4) for clamping onto the anchor cable, and three intelligent snap rings (4) are provided for each anchor cable, which are respectively located at the anchorage section, the free section, and the anchor head; The intelligent snap ring (4) includes a ring body (41) and an intelligent anchoring component. The intelligent anchoring component can open the ring body (41) for snap ring 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 intelligent snap ring (4); The intelligent snap ring (4) includes: A first sliding piece (42) and a second sliding piece (43) are slidably connected to the inner surface of the ring body (41). The first sliding piece (42) and the second sliding piece (43) are respectively used to carry the wireless resistance strain gauge (1) and the wireless ultrasonic transmitting sheet (3). One side of the first sliding piece (42) and the first sliding piece (42) close to each other are respectively fixedly connected with a first rack (44) and a second rack (45). The first rack (44) and the second rack (45) are arranged oppositely and are both arc-shaped racks; A circular ring (46) is provided on the ring body (41). A rotating shaft (47) is rotatably connected in the circular ring (46). The outer end of the rotating shaft (47) is fixedly connected with a rotary driving member (48). The inner end of the rotating shaft (47) is an anti-slip end (49). A toothed rod (410) is sleeved on the rotating shaft (47), and the toothed rod (410) can be engaged with the first rack (44) and the second rack (45).

2. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 1, characterized in that: The intelligent detection and early warning system for tunnel anchor cable damage also includes a power supply module. The power supply module is installed on the intelligent snap 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 and is connected to an external power supply. The receiving coil is installed inside the intelligent snap ring (4), and the receiving coil is connected to the lithium battery.

3. The intelligent detection and warning system for tunnel cable damage according to claim 1, characterized in that: The multi-source data acquisition module includes: 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). The wireless ultrasonic acquisition unit non-invasively measures the wall thickness of the anchor cable through ultrasonic waves, enabling the data analysis and warning module to compare the initial wall thickness and the current wall thickness and calculate the corrosion degree of the anchor cable.

4. The intelligent detection and early warning system for tunnel cable damage according to claim 1, wherein: The wireless transmission module includes 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 intensity through signal amplification and removes noise through filtering. The data acquisition and processing unit (22) converts the amplified voltage and ultrasonic signals into digital signals. The wireless transmission unit (23) modulates the electrical signal into a form transmitted in the wireless channel, compresses the data, and transmits the data to the data analysis and warning module.

5. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 1, characterized in that: The data analysis and warning module includes: Data preprocessing unit: Receives the data from the wireless transmission module and performs cleaning, formatting, and normalization processing on the data. Feature selection unit: Uses machine learning algorithms to screen out features that have a significant impact on the prediction of the remaining life of the anchor cable and the assessment of the risk level from the preprocessed data. Model training and cross-validation unit: Constructs a prediction model according to the selected machine learning algorithm. By means of cross-validation, the data set is divided into a training set and a validation set, and the model is trained and its performance is evaluated multiple times. Prediction and evaluation unit: Uses the trained model to predict the remaining life of the anchor cable and evaluate the risk level for the processing results of two different types of data. The prediction results include the remaining service life of the anchor cable and the corresponding risk level. Warning and notification unit: According to the results of prediction and evaluation, determines whether the remaining life of the anchor cable reaches the preset warning value. Once it reaches or exceeds the warning value, the system will automatically trigger the warning mechanism and send a warning notification to relevant personnel via email, text message, or system prompt.

6. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 1, characterized in that: The wireless resistance strain gauge (1) and the wireless ultrasonic transmitter (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 transmitter (3).

7. The intelligent detection and early warning system for tunnel anchor cable damage according to claim 6, characterized in that: The rotary drive member (48) is set as a servo motor. When it is set as a servo motor, the servo motor is signal-connected to the intelligent anchoring assembly and the data analysis and warning module.

8. An intelligent detection and early warning system for tunnel cable damage according to claim 1 or 7, characterized in that: 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 is connected by clamping, 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 threads, while the second half-ring is provided with threaded holes.

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