A comprehensive pipeline corridor structural health monitoring system based on distributed optical fiber sensing

Abstract

The present invention provides a comprehensive pipeline corridor structural health monitoring system based on distributed fiber optic sensing, which relates to the field of engineering detection technology. The system includes: a laying module for laying waterproof and corrosion-resistant fiber optic sensing cables in the pipeline corridor structure, and setting positioning reference points and coordinate calibration reference points in the top center areas of both ends of the pipeline corridor to build a linear reference system covering the entire length of the pipeline corridor; an acquisition module for connecting the fiber optic sensing cables to distributed fiber optic temperature measurement devices and distributed fiber optic strain devices, and collecting temperature distribution data and strain distribution data in the pipeline corridor based on the principles of Raman scattering and Brillouin scattering to form a monitoring data set. The present invention uses distributed fiber optic sensing technology to collect multi-dimensional pipeline corridor temperature and strain data in real time, and combines redundant monitoring, dynamic compensation, and intelligent early warning mechanisms to achieve structural health monitoring.

Description

Technical Field

[0001] The present invention relates to the field of engineering detection technology, and in particular to an integrated pipe gallery structure health monitoring system based on distributed optical fiber sensing. Background Art

[0002] In urban underground integrated pipeline corridors, traditional structural health monitoring technology has some limitations. It is difficult to balance the monitoring accuracy and coverage of traditional point sensors. For example, when using strain gauges to monitor the strain of pipeline corridor walls, only local data of the installation point can be obtained. When a tiny crack occurs somewhere in the pipeline corridor due to geological subsidence, if the crack is not within the monitoring range of the strain gauge, it cannot be detected in time. If the monitoring range is to be expanded, the number of sensors needs to be increased significantly, which not only increases the cost, but also may affect the overall monitoring accuracy due to the accumulation of errors in the sensors themselves.

[0003] Furthermore, traditional monitoring systems have high maintenance costs and lack real-time performance. Sensors are susceptible to interference from the complex electromagnetic environment within the tunnel, leading to data anomalies. Once a fault occurs, circuits and sensors must be individually inspected, resulting in extremely low efficiency. Due to aging sensor circuits, localized vibration data in the tunnel continues to show false alarms, requiring days to locate and repair the problem. During this time, the tunnel's true vibration status cannot be accurately determined, missing the optimal early warning opportunity and highlighting the shortcomings of traditional technologies in comprehensive tunnel health monitoring. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a comprehensive pipeline corridor structure health monitoring system based on distributed optical fiber sensing, so as to realize efficient and intelligent monitoring of the pipeline corridor health status and timely early warning of potential risks.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] In the first aspect, a comprehensive pipe gallery structural health monitoring system based on distributed optical fiber sensing includes:

[0007] The laying module is used to lay waterproof and corrosion-resistant fiber optic sensor cables in the corridor structure, and set positioning reference points and coordinate calibration reference points in the top center area of ​​both ends of the corridor to build a linear reference system covering the entire length of the corridor;

[0008] The acquisition module is used to connect the optical fiber sensing cable with the distributed optical fiber temperature measurement device and the distributed optical fiber strain measurement device, and collect the temperature distribution data and strain distribution data in the pipeline corridor based on the principles of Raman scattering and Brillouin scattering to form a monitoring data set;

[0009] The compensation module is used to compensate the strain distribution data in real time by laying parallel optical cables with temperature compensation and combining the temperature distribution data to obtain compensated strain distribution data;

[0010] The monitoring module is used to set up redundant monitoring nodes at the fiber optic cable joints and corrosion-prone areas based on the compensated strain distribution data and to seal the nodes with sealant to trigger the seal layer integrity detection instruction;

[0011] The correction module is used to regularly detect signal attenuation data of optical fiber sensor cables based on optical time domain reflectometry. It also generates a linear correction value representing the overall deformation of the tunnel by calculating the propagation time offset of the optical signal between the two detection points, in combination with a linear reference system constructed using positioning reference points and coordinate calibration reference points.

[0012] The early warning module is used to integrate temperature distribution data, compensated strain distribution data, signal attenuation data and linear correction values ​​into the monitoring platform. By analyzing abnormal temperature gradients, strain mutations, signal attenuation trends and changes in linear correction values, it can provide real-time early warning of the risks of water seepage in the pipeline corridor and local structural deformation and deviation.

[0013] Furthermore, the optical fiber sensing cable is connected to a distributed optical fiber temperature measuring device and a distributed optical fiber strain measuring device. Based on the principles of Raman scattering and Brillouin scattering, the temperature distribution data and strain distribution data in the pipeline corridor are collected to form a monitoring data set, including:

[0014] A distributed optical fiber temperature measurement device injects a pulsed optical signal with a preset pulse width and peak power into the optical fiber sensing cable, capturing the Stokes light and anti-Stokes light signals in the Raman backscatter in real time. Based on the light intensity ratio of the two and the preset temperature calibration relationship, it generates meter-level resolution temperature distribution data along the axial direction of the tunnel.

[0015] During the injection of the pulsed optical signal, the distributed optical fiber strain device is synchronously triggered to transmit a frequency-sweep probe light to the same optical fiber sensing cable. The Brillouin frequency shift of each optical fiber point is measured by Brillouin optical time-domain reflectometry. Combined with the frequency shift-strain conversion coefficient, the original strain distribution data including temperature interference is generated.

[0016] The temperature gradient data and the original strain distribution data are aligned in time and space, and millisecond-level synchronization timestamps are added to both. Based on the pre-set segmented coded coordinates of the optical fiber and cable corridor, the temperature data and strain data are matched segment by segment according to the spatial position to form a monitoring data set with temporal and spatial correlation.

[0017] Furthermore, the strain distribution data is compensated in real time by laying temperature-compensated parallel optical cables in combination with the temperature distribution data to obtain compensated strain distribution data, including:

[0018] Inside the tunnel structure, a reference optical cable is laid parallel to the main sensing optical cable along its route. The two cables are spaced at a preset distance and fixed in the same way to ensure that the main and reference optical cables are at the same temperature.

[0019] Based on the spatiotemporal correlation monitoring data set, the original strain values ​​at each spatial location of the main optical cable and the Brillouin frequency shift data of the corresponding reference optical cable are synchronously extracted. Through a preset coordinate mapping algorithm, the frequency shift data of the main optical cable and the reference optical cable are spatially aligned according to the corridor segment coding;

[0020] For each spatial location point corresponding to the tunnel segment code, the difference in Brillouin frequency shift between the main optical cable and the reference optical cable is calculated. Considering the characteristic that the frequency shift of the reference optical cable is only caused by temperature changes, a frequency shift compensation value is generated to characterize the effect of temperature on the strain measurement of the main optical cable.

[0021] According to the real-time temperature distribution data of the main optical cable, the frequency shift compensation amount is converted into a temperature-coupled strain component using the preset temperature-strain relationship parameter library, and the temperature-coupled strain component is dynamically deducted from the original strain distribution data of the main optical cable to obtain the strain distribution data after temperature compensation.

[0022] Furthermore, for the spatial position points corresponding to each tunnel segment code, the difference in Brillouin frequency shift between the main optical cable and the reference optical cable is calculated. Combined with the characteristic that the frequency shift of the reference optical cable is only caused by temperature changes, a frequency shift compensation value is generated to characterize the effect of temperature on the strain measurement of the main optical cable, including:

[0023] At the spatial position points corresponding to the tunnel segment codes, a preset coordinate mapping algorithm is used to align the Brillouin frequency shift data of the main optical cable and the reference optical cable at the same spatial resolution.

[0024] The reference optical cable is fixedly connected to a non-stressed support through an elastic isolation layer to isolate the reference optical cable from external mechanical strain, ensuring that the frequency shift only reflects the temperature change at the corresponding location.

[0025] Based on the material consistency characteristics of the main optical cable and the reference optical cable, the corresponding relationship parameters between the temperature change and the frequency shift of the two are pre-determined through calibration, the frequency shift difference between the main optical cable and the reference optical cable is calculated, and the frequency shift component caused by temperature change in the main optical cable is extracted;

[0026] The frequency shift component is used as a dynamic compensation amount. Combined with the real-time temperature data collected by the distributed optical fiber temperature measurement device, the correlation between the compensation amount and temperature change is verified. The main optical cable strain data is dynamically corrected by the preset temperature-frequency shift compensation coefficient to generate a frequency shift compensation amount that characterizes the influence of temperature on the main optical cable strain measurement.

[0027] Furthermore, based on the compensated strain distribution data, redundant monitoring nodes are set at the fiber optic cable joints and corrosion-prone areas based on the fiber optic sensing cable, and the nodes are waterproofed with sealant to trigger the sealing layer integrity detection instruction, including:

[0028] Based on the compensated strain distribution data, the strain values ​​of the coding points of each section of the corridor are extracted. By setting the dynamic strain threshold, the high-risk corridor sections with strain value mutation amplitudes greater than the preset safety range are identified, and the coordinate set of the abnormal area is generated.

[0029] For the coordinate set of the abnormal area, two redundant sensor optical cables are laid in parallel at a preset interval along the laying path of the main sensor optical cable in the corresponding tunnel segment;

[0030] For the joints of the main optical cable and redundant optical cable in the abnormal area, first scrape off the oxide layer on the joint surface, then wrap waterproof tape to cover the metal connection parts, and finally pour waterproof sealant to form a sealing layer with a thickness greater than 5 mm. The sealing range extends to the inner wall of the adjacent pipe gallery to form a seamless bond;

[0031] The compensated strain data of the main optical cable and the redundant optical cable are collected synchronously in real time. When the deviation between the strain data of a certain section of the main optical cable and the redundant optical cable data is greater than the preset tolerance, the section is automatically marked as a cable failure risk section, and the redundant optical cable data is used as the monitoring basis to trigger the sealing layer integrity detection instruction.

[0032] Furthermore, for optical fiber sensor cables, signal attenuation data is regularly detected based on optical time domain reflectometry. Combined with a linear reference system constructed using positioning benchmark reference points and coordinate calibration reference points, the propagation time offset of the optical signal between the two detection points is calculated to generate a linear correction value representing the overall deformation of the tunnel, including:

[0033] The optical time domain reflectometer injects detection light pulses into the optical fiber sensor cable at a preset period, collects the backscattered signal of the entire cable section, extracts the signal attenuation intensity and attenuation rate per unit time at each tunnel segment coding point, and generates an attenuation feature data set including a timestamp;

[0034] Based on the three-dimensional coordinates of the positioning reference points at both ends of the corridor and the geometric distribution of the coordinate calibration reference points, a linear spatial coordinate system based on the corridor axis is constructed. By calibrating the correspondence between the optical signal propagation time and the actual length of the corridor, a mapping table between time and spatial position is established, in which the propagation time of each corridor segment coding point accurately corresponds to the spatial coordinate.

[0035] Compare the current attenuation feature dataset with the propagation time data of the initial reference period. Calculate the propagation time offset of the optical signal from the start point to the end point for the segmented code detection points at both ends of the same tunnel. Convert the time offset into axial deformation displacement based on a mapping table between time and spatial position.

[0036] A weighted linear fitting analysis is performed on the axial deformation displacement of all tunnel segments. After eliminating abnormal displacement data that deviates from the overall trend, a straight line correction value representing the overall deformation of the tunnel is generated, including deformation direction, displacement and displacement fluctuation range parameters.

[0037] Furthermore, the temperature distribution data, compensated strain distribution data, signal attenuation data, and linear correction values ​​are integrated into the monitoring platform. By analyzing abnormal temperature gradients, sudden strain changes, signal attenuation trends, and linear correction value changes, real-time warnings of pipeline corridor water seepage and local structural deformation and deviation risks are provided, including:

[0038] The temperature gradient threshold, post-compensation strain mutation threshold, signal attenuation rate threshold, and linear correction value displacement tolerance range are set in the monitoring platform, and the priority relationship of each parameter is dynamically adjusted according to the safety level of the tunnel structure;

[0039] Based on the corridor segment coding coordinates, the temperature distribution data, compensated strain values, signal attenuation rates, and linear correction value displacements of the same segment coding are spatiotemporally aligned to generate a multi-dimensional dynamic correlation data set including timestamps. Each data set corresponds to the complete monitoring parameters of a corridor segment, and decision logic is executed on the multi-dimensional dynamic correlation data set.

[0040] Based on the judgment logic, redundant data verification is performed on the segments marked with risks, and the compensated strain data of the redundant optical cables is extracted. If the strain deviation between the main optical cable and the redundant optical cable is greater than the preset tolerance range, it is determined to be a local failure of the optical cable and the failure coordinates are output. If the fluctuation amplitude is greater than the allowable range of elastic deformation of the corridor design, it is determined to be a composite structural risk.

[0041] When a tunnel segment larger than the preset ratio triggers water seepage and local deformation warnings at the same time, and the displacement of the linear correction value exceeds the overall deformation threshold for multiple cycles, it is determined that there is a risk of overall tunnel deviation and optical cable failure, and an alarm is generated.

[0042] Furthermore, the judgment logic includes that when the temperature gradient changes negatively by a larger amount than a threshold value within a preset time, and the signal attenuation rate shows an upward trend over multiple detection cycles, it is marked as a water seepage risk and a level one alarm is triggered; if the strain value after compensation is greater than the threshold value over multiple detection cycles, and at the same time, the cumulative growth of the linear correction value displacement in the same direction is greater than a preset ratio of the tolerance range, it is determined as a cumulative risk of local structural deformation and a level two alarm is triggered.

[0043] In a second aspect, a computing device includes:

[0044] one or more processors;

[0045] The storage device is used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the system.

[0046] According to a third aspect, a computer-readable storage medium stores a program, which implements the system when executed by a processor.

[0047] The above solution of the present invention includes at least the following beneficial effects:

[0048] Distributed fiber optic sensing technology enables millimeter-level spatial resolution monitoring along the entire length of the utility corridor. Unlike the discrete placement of traditional point sensors, this technology can detect subtle changes in the corridor structure (such as concrete cracks, pipe joint displacement, and foundation settlement) in real time. For example, within a 10-kilometer-long utility corridor, it can precisely locate areas of strain anomaly within a 0.5-meter radius, avoiding risks of missed detection due to blind spots and ensuring that the structural status of every corner of the corridor is captured in real time. The integration of fiber Bragg grating (FBG) and distributed fiber optic strain / temperature sensing technology simultaneously acquires multi-dimensional data on strain, temperature, vibration, and leakage from the utility corridor structure. Through data fusion analysis, it accurately identifies anomaly correlations. When a sudden temperature rise (such as a precursor to a cable fault) or a sudden strain change (such as an abnormal structural stress) occurs in a specific location in the utility corridor, the nature of the anomaly can be quickly determined, reducing misjudgments associated with single-parameter monitoring and improving the accuracy of anomaly diagnosis in complex environments. As a passive sensing medium, optical fiber is immune to electromagnetic interference (it can withstand strong electromagnetic environments exceeding 10 kV / m), ensuring stable operation in the complex operating environment of power and communication equipment in the utility corridor. At the same time, the sensing fiber has a lifespan of over 20 years, reducing equipment replacement and calibration costs by 70% compared to traditional electronic sensors (with an average replacement cycle of 5-8 years). It supports remote online self-testing and uses optical time domain reflectometry (OTDR) technology to locate fiber link fault points in real time (with a positioning accuracy of ≤1 meter), improving operation and maintenance efficiency and reducing manual troubleshooting costs. Based on real-time monitoring data from distributed optical fibers, multi-level warning thresholds can be dynamically set. When tunnel structural parameters (such as strain and vibration amplitude) exceed the safe range, warnings are immediately issued through audible and visual alarms and mobile push notifications. Compared to traditional monitoring systems, the response time to abnormal events is shortened from 24 hours to less than 15 minutes. Data from a pilot tunnel application shows that the system can identify structural safety hazards caused by uneven foundation settlement 48 hours in advance, giving operation and maintenance personnel sufficient time to respond and effectively reducing the incidence of major accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic diagram of an integrated pipeline corridor structure health monitoring system based on distributed optical fiber sensing provided by an embodiment of the present invention.

[0050] Figure 2 This is a flow chart of an embodiment of the present invention, which provides a comprehensive pipeline corridor structure health monitoring system based on distributed optical fiber sensing, which compensates strain data in real time by laying temperature-compensated parallel optical cables and combining temperature distribution data to obtain compensated strain distribution data. DETAILED DESCRIPTION

[0051] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0052] like Figure 1 As shown, an embodiment of the present invention provides a comprehensive pipe gallery structure health monitoring system based on distributed optical fiber sensing, comprising:

[0053] Laying module 1 is used to lay waterproof and corrosion-resistant fiber optic sensor cables in the corridor structure, and set positioning reference points and coordinate calibration reference points in the top center area of ​​both ends of the corridor to build a linear reference system covering the entire length of the corridor;

[0054] Acquisition module 2 is used to connect the optical fiber sensing cable to the distributed optical fiber temperature measurement device and the distributed optical fiber strain measurement device, and collect the temperature distribution data and strain distribution data in the pipeline corridor based on the principles of Raman scattering and Brillouin scattering to form a monitoring data set;

[0055] Compensation module 3 is used to compensate the strain distribution data in real time by combining the temperature distribution data with the temperature compensation parallel optical cable laying method to obtain compensated strain distribution data;

[0056] Monitoring module 4 is used to set redundant monitoring nodes at the optical cable joints and corrosion-prone areas based on the optical fiber sensing cable according to the compensated strain distribution data, and to waterproof the nodes with sealant to trigger the sealing layer integrity detection instruction;

[0057] Correction module 5 is used to periodically detect signal attenuation data of the optical fiber sensor cable based on optical time domain reflectometry. It also uses a linear reference system constructed using positioning reference points and coordinate calibration reference points to calculate the propagation time offset of the optical signal between the two detection points to generate a straight line correction value representing the overall deformation of the tunnel.

[0058] Early warning module 6 is used to integrate temperature distribution data, compensated strain distribution data, signal attenuation data and linear correction values ​​into the monitoring platform. By analyzing abnormal temperature gradients, strain mutations, signal attenuation trends and changes in linear correction values, it can provide real-time early warning of the risks of water seepage in the pipeline corridor and local structural deformation and deviation.

[0059] In an embodiment of the present invention, by laying waterproof and corrosion-resistant fiber optic sensor cables, it is possible to effectively adapt to the humid, highly corrosive, and complex environment within the integrated utility corridor, extend the service life of the sensing equipment, and reduce monitoring failures caused by environmental factors. Positioning reference points and coordinate calibration reference points are set at the tops of both ends of the corridor to construct a linear reference system covering the entire length, providing a unified and stable spatial coordinate reference for overall deformation monitoring of the corridor, ensuring the consistency and comparability of monitoring data at different time periods, and avoiding misjudgment of structural status due to reference deviations. Using distributed fiber optic temperature and strain measurement devices, based on the principles of Raman scattering and Brillouin scattering, real-time temperature and strain distribution data within the corridor can be collected, enabling full-scale, continuous monitoring of the corridor's structural status. Compared to traditional point sensors, it can capture millimeter-level temperature anomalies (such as cable overheating) and micro-strain changes (such as early cracks in concrete). The resulting monitoring data set covers multi-dimensional physical parameters. By laying temperature-compensated parallel optical cables and combining them with real-time temperature distribution data, the original strain data is corrected to eliminate the interference of temperature changes on structural strain monitoring (such as pseudo-strain signals caused by thermal expansion and contraction). This ensures that the compensated strain distribution data truly reflects the stress and deformation of the tunnel structure, improves the reliability of the monitoring results, avoids abnormal misjudgments caused by temperature coupling effects, and provides a more reliable basis for structural safety assessment. Redundant monitoring nodes are set up at optical cable joints and corrosion-prone areas to strengthen the key monitoring of weak links in the tunnel (such as sealing failure at connections and corrosion-prone points), avoiding the risk of missed inspections at key locations. The nodes are waterproofed with sealant to prevent the intrusion of water vapor and corrosive media that affect the performance of the monitoring equipment. It can also trigger the sealing layer integrity detection command to actively identify potential hidden dangers such as node sealing failure, provide early warning of leakage risks, and reduce the cost of manual inspections. By regularly detecting fiber optic signal attenuation data through optical time domain reflection technology and calculating the optical signal propagation time offset in combination with the positioning reference system, the overall deformation of the tunnel (such as the linear offset caused by foundation settlement) can be accurately captured. The generated straight line correction value can dynamically calibrate the monitoring data and eliminate the accumulated errors caused by slow structural deformation during long-term use.

[0060] In a preferred embodiment of the present invention, the optical fiber sensing cable is connected to a distributed optical fiber temperature measuring device and a distributed optical fiber strain measuring device. Based on the principles of Raman scattering and Brillouin scattering, temperature distribution data and strain distribution data in the pipeline corridor are collected to form a monitoring data set, which may include:

[0061] A distributed optical fiber temperature measurement device injects a pulsed optical signal with a preset pulse width and peak power into the optical fiber sensing cable, capturing the Stokes light and anti-Stokes light signals in the Raman backscatter in real time. Based on the light intensity ratio of the two and the preset temperature calibration relationship, it generates meter-level resolution temperature distribution data along the axial direction of the tunnel.

[0062] During the injection of the pulsed optical signal, the distributed optical fiber strain device is synchronously triggered to transmit a frequency-sweep probe light to the same optical fiber sensing cable. The Brillouin frequency shift of each optical fiber point is measured by Brillouin optical time-domain reflectometry. Combined with the frequency shift-strain conversion coefficient, the original strain distribution data including temperature interference is generated.

[0063] The temperature gradient data and the original strain distribution data are aligned in time and space, and millisecond-level synchronization timestamps are added to both. Based on the pre-set segmented coded coordinates of the optical fiber and cable corridor, the temperature data and strain data are matched segment by segment according to the spatial position to form a monitoring data set with temporal and spatial correlation.

[0064] In an embodiment of the present invention, a distributed fiber optic temperature measurement device injects a specific pulsed optical signal with a preset pulse width and peak power into a fiber optic sensing cable. When the optical signal propagates through the optical fiber, it generates Raman backscattering, which includes both Stokes and anti-Stokes light signals. The device captures these two optical signals in real time and compares their intensity ratios, using a preset temperature calibration relationship to calculate the relationship between the intensity ratio and temperature. Based on this relationship, the intensity ratio is converted into temperature data, generating temperature distribution data with meter-level resolution along the tunnel's axial direction. This effectively assigns a temperature value to each meter section of the tunnel. During the same timeframe as the pulsed optical signal is injected, a distributed fiber optic strain gauge is synchronously triggered to emit swept-frequency probe light into the same fiber optic sensing cable. This probe light propagates through the optical fiber and, upon encountering minute changes in strain, generates Brillouin scattering. Using Brillouin optical time-domain reflectometry, the Brillouin frequency shift at each point on the fiber is measured. Different strain conditions result in different Brillouin frequency shifts. Using a pre-defined frequency-shift-strain conversion coefficient, the measured frequency shift is converted into strain data. This yields raw strain distribution data, including temperature interference, and determines the strain conditions at each location in the tunnel. After obtaining the temperature gradient data and raw strain distribution data, they are first subjected to spatiotemporal alignment. A synchronized timestamp with millisecond accuracy is appended to both sets of data to ensure temporal consistency. Then, based on the tunnel segment-coded coordinates pre-set on the optical fiber cable, the temperature and strain data are matched segment by segment according to their spatial location. Each coded coordinate corresponds to a specific location in the tunnel. This allows the temperature and strain data at the same spatial location to be linked, ultimately forming a spatiotemporally correlated monitoring dataset, allowing the temperature and strain data to be aligned and presented collaboratively across both temporal and spatial dimensions.

[0065] By collecting data based on the principles of Raman scattering and Brillouin scattering, high-precision measurements of temperature and strain within the tunnel can be achieved. Meter-level resolution of temperature distribution data and precise strain data acquisition allows for the timely detection of any subtle temperature changes and structural deformations within the tunnel, providing a strong guarantee for safe tunnel operation monitoring. Real-time capture of optical signals and data generation ensures real-time data availability. Adding millisecond-level synchronized timestamps to temperature and strain data achieves high temporal synchronization, avoiding data bias and misjudgment caused by time differences and ensuring more accurate and reliable monitoring results. Temperature and strain data are matched segment by segment according to spatial location to form a spatiotemporally correlated monitoring dataset. This eliminates data isolation and enables comprehensive analysis of tunnel conditions from both temporal and spatial dimensions. The simultaneous collection and integration of two key parameters, temperature and strain, provides a more comprehensive picture of the tunnel's actual condition than single-parameter monitoring.

[0066] In a preferred embodiment of the present invention, the strain distribution data is compensated in real time by laying a temperature-compensated parallel optical cable in combination with the temperature distribution data to obtain compensated strain distribution data, which may include:

[0067] Inside the tunnel structure, a reference optical cable is laid parallel to the main sensing optical cable along its route. The two cables are spaced at a preset distance and fixed in the same way to ensure that the main and reference optical cables are at the same temperature.

[0068] Based on the spatiotemporal correlation monitoring data set, the original strain values ​​at each spatial location of the main optical cable and the Brillouin frequency shift data of the corresponding reference optical cable are synchronously extracted. Through a preset coordinate mapping algorithm, the frequency shift data of the main optical cable and the reference optical cable are spatially aligned according to the corridor segment coding;

[0069] For each spatial location point corresponding to the tunnel segment code, the difference in Brillouin frequency shift between the main optical cable and the reference optical cable is calculated. Considering the characteristic that the frequency shift of the reference optical cable is only caused by temperature changes, a frequency shift compensation value is generated to characterize the effect of temperature on the strain measurement of the main optical cable.

[0070] According to the real-time temperature distribution data of the main optical cable, the frequency shift compensation amount is converted into a temperature-coupled strain component using the preset temperature-strain relationship parameter library, and the temperature-coupled strain component is dynamically deducted from the original strain distribution data of the main optical cable to obtain the strain distribution data after temperature compensation.

[0071] In an embodiment of the present invention, a reference optical cable is laid parallel to the main sensing optical cable within the tunnel structure, along the route of the main sensing optical cable. A preset spacing, ranging from a few centimeters to tens of centimeters, is maintained between the two cables. This spacing ensures that the ambient temperature of the two cables is essentially the same while preventing mutual interference. Furthermore, they are mounted on the tunnel using the same fixing method, such as using the same fixture and tightening force, to ensure that the temperature response of the main and reference optical cables is consistent when the temperature changes, allowing the reference optical cable to serve as a benchmark for reflecting ambient temperature changes. From the previously generated spatiotemporal correlation monitoring dataset, the raw strain values ​​of the main optical cable at each spatial location are simultaneously extracted, along with the Brillouin frequency shift data of the corresponding reference optical cable at the same location. Because the actual positions of the main and reference optical cables on the tunnel may vary slightly, a preset coordinate mapping algorithm is used to process these deviations. This algorithm precisely aligns the frequency shift data of the main and reference optical cables according to their spatial locations based on the tunnel segment coding, ensuring that the data for both cables, under the same tunnel segment coding, corresponds to the same actual location in the tunnel.

[0072] For each spatial location corresponding to the tunnel segment code, the difference in Brillouin frequency shift between the main optical cable and the reference optical cable is calculated. Because the frequency shift of the reference optical cable is caused by temperature changes (due to its installation and environment being identical to the main optical cable), this frequency shift difference reflects the impact of temperature changes on the strain measurement of the main optical cable. This difference is then used as the frequency shift compensation. This compensation quantifies the degree of temperature interference with the strain measurement of the main optical cable. Based on the real-time temperature distribution data of the main optical cable, the corresponding temperature-strain relationship parameters are retrieved from a pre-set temperature-strain relationship parameter library. Using these parameters, the frequency shift compensation is converted into a temperature-coupled strain component, which represents the false strain data generated by the main optical cable due to temperature changes. Finally, this temperature-coupled strain component is dynamically subtracted from the original strain distribution data of the main optical cable. The resulting data is the temperature-compensated strain distribution data, which truly reflects the strain caused by the actual stress factors in the tunnel structure.

[0073] By installing a reference optical cable and performing temperature compensation, the interference of temperature changes on strain measurement of the main optical cable is eliminated. This eliminates spurious strain information generated by temperature fluctuations in the strain distribution data, accurately reflecting the actual strain conditions of the tunnel structure, improving strain measurement accuracy and providing reliable data support for tunnel safety assessments. This temperature compensation method does not rely on complex external ambient temperature measurement equipment. Instead, it achieves compensation simply by comparing two parallel optical cables, minimizing the impact of external equipment failures or measurement errors. Furthermore, because the main and reference optical cables are installed in the same manner and environment, the impact of environmental factors during long-term operation is minimal. This allows the monitoring system to operate stably under varying temperature conditions, ensuring the reliability and consistency of the monitoring data. Combining real-time temperature distribution data with a preset parameter library enables real-time dynamic compensation of the raw strain data. When the tunnel temperature changes, the system can immediately detect and quickly calculate the compensation amount, updating the strain data in a timely manner, ensuring that the strain monitoring results accurately reflect the tunnel structure status at any given moment. Compared to some complex temperature compensation algorithms, this temperature compensation method based on parallel optical cables offers a clear principle and simple operation. During the data processing process, only basic operations such as data extraction, difference calculation and parameter conversion are required, without the need for complex mathematical models and large amounts of computing resources.

[0074] In a preferred embodiment of the present invention, for each spatial position point corresponding to the tunnel segment code, the difference in Brillouin frequency shift between the main optical cable and the reference optical cable is calculated. In combination with the characteristic that the frequency shift of the reference optical cable is only caused by temperature changes, a frequency shift compensation value representing the effect of temperature on the strain measurement of the main optical cable is generated, which may include:

[0075] At the spatial position points corresponding to the tunnel segment codes, a preset coordinate mapping algorithm is used to align the Brillouin frequency shift data of the main optical cable and the reference optical cable at the same spatial resolution.

[0076] The reference optical cable is fixedly connected to a non-stressed support through an elastic isolation layer to isolate the reference optical cable from external mechanical strain, ensuring that the frequency shift only reflects the temperature change at the corresponding location.

[0077] Based on the material consistency characteristics of the main optical cable and the reference optical cable, the corresponding relationship parameters between the temperature change and the frequency shift of the two are pre-determined through calibration, the frequency shift difference between the main optical cable and the reference optical cable is calculated, and the frequency shift component caused by temperature change in the main optical cable is extracted;

[0078] The frequency shift component is used as a dynamic compensation amount. Combined with the real-time temperature data collected by the distributed optical fiber temperature measurement device, the correlation between the compensation amount and temperature change is verified. The main optical cable strain data is dynamically corrected by the preset temperature-frequency shift compensation coefficient to generate a frequency shift compensation amount that characterizes the influence of temperature on the main optical cable strain measurement.

[0079] In an embodiment of the present invention, each segment in the tunnel has a corresponding code. For each coded spatial location, a preset coordinate mapping algorithm is used to process the Brillouin frequency shift data for the main and reference cables. This algorithm accurately maps the frequency shift data for the two cables to the same spatial location with the same spatial resolution, based on the tunnel's spatial coordinate system. For example, the frequency shift data for the main cable at a certain meter segment is accurately matched with the frequency shift data for the reference cable at the same meter segment, ensuring that the calculations are based on the same spatial location. During installation, the reference cable is securely connected to a non-stress-bearing support via an elastic isolation layer. The elastic isolation layer absorbs and buffers external mechanical stress, while the non-stress-bearing support ensures that the reference cable does not generate mechanical strain due to deformation of the tunnel structure. During tunnel operation, the frequency shift generated by the reference cable is only affected by temperature changes and does not include strain frequency shift caused by external mechanical forces, thus providing a pure data benchmark for temperature measurement. Because the main optical cable and the reference optical cable are made of the same material, their response characteristics to temperature changes are consistent. Previously, the corresponding relationship parameters between temperature change and frequency shift were determined. In practice, the frequency shifts of the main and reference optical cables at the same spatial location are compared, and the difference is calculated. Using the predetermined corresponding relationship parameters, the frequency shift component caused by temperature change in the main optical cable can be accurately extracted from this difference. This component reflects the temperature interference on the main optical cable strain measurement. The extracted frequency shift component is used as a dynamic compensation variable. Combined with real-time temperature data collected by the distributed fiber optic temperature measurement device, the correlation between the compensation and temperature change is verified. The accuracy of the compensation is confirmed by verifying the consistency of the change trends between the two. The strain data of the main optical cable is then dynamically corrected based on a preset temperature-frequency shift compensation coefficient. This coefficient, set based on the relationship between temperature change and frequency shift, is used to appropriately apply the compensation to the main optical cable strain data, ultimately generating a frequency shift compensation value that accurately represents the impact of temperature on the main optical cable strain measurement.

[0080] By isolating the mechanical strain of the reference optical cable, ensuring that its frequency shift is solely due to temperature, and combining the material consistency of the main reference optical cable for precise calculation, the system eliminates temperature-related errors in the strain measurement of the main optical cable. This ensures that the measured strain data more accurately reflects the strain caused by actual forces acting on the tunnel structure, providing a more reliable basis for tunnel safety assessments. Correlation verification between the frequency shift compensation and real-time temperature data and dynamic correction using preset coefficients ensures the scientific and accurate nature of the compensation process, reduces erroneous compensation due to accidental factors or calculation errors, and ensures that the resulting frequency shift compensation is more accurate and aligns with actual conditions, enhancing the reliability of the monitoring data and preventing misjudgments caused by data errors. The use of an elastic isolation layer and a non-stressed support for mounting the reference optical cable reduces external mechanical interference on the measurement at the hardware level, mitigating measurement instability caused by mechanical vibration and structural deformation. Furthermore, data processing based on pre-calibrated parameters and a verification mechanism ensures stable operation under diverse environmental conditions, ensuring the continuity and effectiveness of monitoring operations. Dynamic correction of the main optical cable strain data using real-time temperature data and preset coefficients promptly responds to temperature changes within the tunnel. Regardless of whether the temperature changes slowly or fluctuates rapidly, the appropriate frequency shift compensation can be quickly calculated and the main optical cable strain data can be accurately adjusted to ensure that the strain monitoring results at any time can truly reflect the structural status of the tunnel.

[0081] In a preferred embodiment of the present invention, based on the compensated strain distribution data, redundant monitoring nodes are set at the optical cable joints and corrosion-prone areas based on the optical fiber sensing cable, and the nodes are waterproof sealed with sealant to trigger the sealing layer integrity detection instruction, which may include:

[0082] Based on the compensated strain distribution data, the strain values ​​of the coding points of each section of the corridor are extracted. By setting the dynamic strain threshold, the high-risk corridor sections with strain value mutation amplitudes greater than the preset safety range are identified, and the coordinate set of the abnormal area is generated.

[0083] For the coordinate set of the abnormal area, two redundant sensor optical cables are laid in parallel at a preset interval along the laying path of the main sensor optical cable in the corresponding tunnel segment;

[0084] For the joints of the main optical cable and redundant optical cable in the abnormal area, first scrape off the oxide layer on the joint surface, then wrap waterproof tape to cover the metal connection parts, and finally pour waterproof sealant to form a sealing layer with a thickness greater than 5 mm. The sealing range extends to the inner wall of the adjacent pipe gallery to form a seamless bond;

[0085] The compensated strain data of the main optical cable and the redundant optical cable are collected synchronously in real time. When the deviation between the strain data of a certain section of the main optical cable and the redundant optical cable data is greater than the preset tolerance, the section is automatically marked as a cable failure risk section, and the redundant optical cable data is used as the monitoring basis to trigger the sealing layer integrity detection instruction.

[0086] In an embodiment of the present invention, the strain value corresponding to each tunnel segment coding point is extracted from the compensated strain distribution data. A dynamic strain threshold is set based on tunnel operation data and design standards. This threshold is dynamically adjusted based on tunnel operation conditions and environmental factors. The strain value of each segment is compared with the threshold, and the magnitude of the strain change is calculated. If the magnitude of the strain change in a tunnel segment exceeds a preset safety range, the segment is identified as a high-risk area. The coordinates of these high-risk areas are recorded to generate a set of abnormal area coordinates. For each identified abnormal area coordinate set, two redundant optical sensing cables are laid in parallel within the corresponding tunnel segment, along the path of the main sensing cable, at a preset spacing. This spacing is determined based on factors such as the tunnel's structural characteristics and the cable's monitoring accuracy. This ensures that the redundant cables can effectively cover the abnormal area and can promptly take over monitoring work in the event of a problem with the main cable, thereby ensuring the continuity of monitoring data. Within the abnormal area, the joints between the main cable and the newly laid redundant cable are waterproofed and sealed. First, use specialized tools to scrape off the oxide layer on the surface of the connector to ensure a clean, smooth surface and lay the foundation for sealing. Next, carefully wrap the connector with waterproof tape, completely covering the metal connection components for initial waterproofing and protection. Finally, pour waterproof sealant into the connector to form a sealing layer greater than 5 mm thick. At the same time, extend the sealing area to the adjacent tunnel wall to ensure seamless bonding between the sealing layer and the tunnel wall, minimizing the intrusion of moisture and corrosive substances into the connector and protecting the normal operation of the optical cable connector. Real-time synchronous collection of compensated strain data from the main and redundant optical cables is performed. The strain data of a certain section of the main optical cable is continuously compared with the data of the corresponding section of the redundant optical cable. A preset tolerance is set as the judgment standard. When the strain data of a certain section of the main optical cable deviates from the data of the redundant optical cable by more than the preset tolerance, it indicates that the main optical cable may be at risk of failure in that section, and the section is automatically marked as a cable failure risk section. At this time, the data source will be switched immediately, and the data of the redundant optical cable will be used as the new monitoring basis, and the sealing layer integrity detection instruction will be triggered, prompting the staff to inspect the sealing layer in the area and promptly discover and deal with potential problems.

[0087] By setting dynamic strain thresholds, high-risk tunnel sections with excessively large strain fluctuations can be accurately identified, effectively localizing abnormal areas before problems escalate. Combined with redundant optical cable deployment and sealing, this allows for focused monitoring of key tunnel locations, effectively preventing monitoring interruptions or data distortion caused by cable failure or seal damage, saving valuable time for tunnel maintenance and reducing the likelihood of safety incidents. The redundant sensing optical cables allow for immediate monitoring in the event of a primary cable failure, ensuring that monitoring data is not interrupted by the failure of the primary cable. Furthermore, strain data from the primary and redundant cables are compared in real time. If any deviations exceed the specified value, the data source is promptly switched, ensuring that monitoring data remains reliable and accurate, providing an accurate basis for tunnel operational status assessment and fault diagnosis. The optical cable joints undergo a multi-step process of scraping the oxide layer, wrapping with waterproof tape, and injecting waterproof sealant to create a thick, seamless seal, significantly enhancing the joint's waterproof and corrosion resistance. The seal extends to the inner walls of adjacent tunnels, further enhancing the sealing effect and effectively protecting optical cable connectors from harsh environmental corrosion, extending the cable life, and ensuring the long-term stable operation of the fiber optic sensing system. Data deviations between the main and redundant optical cables are automatically detected. Once an anomaly is detected, the risk segment is automatically marked and the data source is switched. It also triggers a seal integrity check command. The entire process requires no human intervention, achieving automated operation and maintenance.

[0088] In a preferred embodiment of the present invention, optical fiber sensor cables are periodically tested for signal attenuation data based on optical time domain reflectometry. A linear reference system constructed by positioning reference points and coordinate calibration reference points is combined to calculate the propagation time offset of the optical signal between the two detection points to generate a linear correction value representing the overall deformation of the tunnel. This may include:

[0089] The optical time domain reflectometer injects detection light pulses into the optical fiber sensor cable at a preset period, collects the backscattered signal of the entire cable section, extracts the signal attenuation intensity and attenuation rate per unit time at each tunnel segment coding point, and generates an attenuation feature data set including a timestamp;

[0090] Based on the three-dimensional coordinates of the positioning reference points at both ends of the corridor and the geometric distribution of the coordinate calibration reference points, a linear spatial coordinate system based on the corridor axis is constructed. By calibrating the correspondence between the optical signal propagation time and the actual length of the corridor, a mapping table between time and spatial position is established, in which the propagation time of each corridor segment coding point accurately corresponds to the spatial coordinate.

[0091] Compare the current attenuation feature dataset with the propagation time data of the initial reference period. Calculate the propagation time offset of the optical signal from the start point to the end point for the segmented code detection points at both ends of the same tunnel. Convert the time offset into axial deformation displacement based on a mapping table between time and spatial position.

[0092] A weighted linear fitting analysis is performed on the axial deformation displacement of all tunnel segments. After eliminating abnormal displacement data that deviates from the overall trend, a straight line correction value representing the overall deformation of the tunnel is generated, including deformation direction, displacement and displacement fluctuation range parameters.

[0093] In an embodiment of the present invention, an optical time-domain reflectometer is used to inject probe light pulses into a fiber optic sensor cable at a preset period. Light propagating through the cable generates backscattered signals. These backscattered signals are collected from the entire cable segment. Then, for each tunnel segment code point, two key metrics, signal attenuation intensity and attenuation rate per unit time, are analyzed and extracted. Each collected data point is accurately timestamped, ultimately forming a timestamped attenuation signature dataset that records the optical signal attenuation for each segment at different time points. Based on the three-dimensional coordinates of the positioning reference points at both ends of the tunnel and the geometric distribution of coordinate calibration reference points within the tunnel, a linear spatial coordinate system is constructed with the tunnel axis as the reference. Within this coordinate system, the correspondence between the optical signal propagation time in the cable and the actual tunnel length is determined. Based on this correspondence, a detailed mapping table between time and spatial position is established. In this mapping table, the optical signal propagation time corresponding to each tunnel segment code point is accurately mapped to a specific spatial coordinate, providing an accurate spatial reference for deformation analysis. The currently collected attenuation signature dataset is carefully compared with the propagation time data collected during the initial reference period. For the detection points at both ends of the same tunnel segment code, the time offset of the optical signal propagating from the starting point to the end point is calculated. This time offset reflects the possible deformation of the segment during this time. Then, based on a previously established mapping table between time and spatial position, this time offset is converted into the corresponding axial deformation displacement, thus translating the temporal variation of the optical signal into actual spatial displacement. A weighted linear fitting analysis is performed on the axial deformation displacements calculated for all tunnel segments. Due to various factors, the displacement data for some segments may exhibit anomalies, deviating from the overall deformation trend. By setting appropriate screening criteria, these anomalous displacement data that deviate from the overall trend are eliminated. The remaining valid data is then comprehensively analyzed and calculated to generate a linear correction value that represents the overall deformation of the tunnel. This linear correction value includes the deformation direction (i.e., the direction of deformation); the displacement (i.e., the magnitude of the overall deformation); and the displacement fluctuation range parameter, which reflects the fluctuation of deformation within a certain range, providing a comprehensive parameter basis for tunnel safety assessment.

[0094] By constructing a precise linear spatial coordinate system and a time-space mapping table, it is possible to accurately convert minute changes in the propagation time of the optical signal into actual axial deformation displacement, thus achieving high-precision monitoring of tunnel deformation. This high-precision monitoring capability can detect small deformations in the early stages of the tunnel, providing strong support for preventive maintenance of the tunnel. By regularly collecting and analyzing attenuation characteristic data according to a preset cycle, it is possible to track the deformation of the tunnel in real time. By comparing it with the initial baseline cycle data, the development trend of the tunnel deformation can be promptly discovered. Once the deformation variable or deformation trend is abnormal, an early warning can be quickly issued. In the process of generating the straight line correction value, a weighted linear fitting analysis is performed on the axial deformation displacement, and abnormal data is eliminated, effectively reducing the impact of accidental factors on the monitoring results. This makes the final deformation data more reliable and can accurately reflect the actual deformation state of the tunnel. The generated straight line correction value includes multiple parameters such as deformation direction, displacement and displacement fluctuation range, which can comprehensively describe the overall deformation of the corridor from multiple angles. Through comprehensive analysis of these parameters, we can gain an in-depth understanding of the structural status of the corridor and judge the impact of deformation on the safety of the corridor, so as to formulate more scientific and reasonable maintenance and repair strategies and improve the operation and maintenance management level of the corridor.

[0095] In a preferred embodiment of the present invention, temperature distribution data, compensated strain distribution data, signal attenuation data, and linear correction values ​​are integrated into a monitoring platform. By analyzing abnormal temperature gradients, sudden strain changes, signal attenuation trends, and linear correction value changes, real-time warnings of pipeline gallery water seepage and local structural deformation offset risks can be provided. This may include:

[0096] The temperature gradient threshold, post-compensation strain mutation threshold, signal attenuation rate threshold, and linear correction value displacement tolerance range are set in the monitoring platform, and the priority relationship of each parameter is dynamically adjusted according to the safety level of the tunnel structure;

[0097] Based on the corridor segment coding coordinates, the temperature distribution data, compensated strain value, signal attenuation rate and linear correction value displacement of the same segment coding are aligned in time and space to generate a multi-dimensional dynamic correlation data set including time stamps. Each data set corresponds to the complete monitoring parameters of a corridor segment, and the judgment logic is executed on the multi-dimensional dynamic correlation data set. Specifically, when the temperature gradient changes negatively and suddenly exceeds the threshold within the preset time, and the signal attenuation rate shows an upward trend for multiple detection cycles, it is marked as a water seepage risk and triggers a level 1 alarm. If the compensated strain value exceeds the threshold for multiple detection cycles, and the cumulative growth of the linear correction value displacement in the same direction exceeds the preset ratio of the tolerance range, it is determined to be a cumulative risk of local structural deformation and triggers a level 2 alarm.

[0098] Based on the judgment logic, redundant data verification is performed on the segments marked with risks, and the compensated strain data of the redundant optical cables is extracted. If the strain deviation between the main optical cable and the redundant optical cable is greater than the preset tolerance range, it is determined to be a local failure of the optical cable and the failure coordinates are output. If the fluctuation amplitude is greater than the allowable range of elastic deformation of the corridor design, it is determined to be a composite structural risk.

[0099] When a tunnel segment larger than the preset ratio triggers water seepage and local deformation warnings at the same time, and the displacement of the linear correction value exceeds the overall deformation threshold for multiple cycles, it is determined that there is a risk of overall tunnel deviation and optical cable failure, and an alarm is generated.

[0100] In an embodiment of the present invention, the monitoring platform sets temperature gradient thresholds, post-compensation strain mutation thresholds, signal attenuation rate thresholds, and tolerance ranges for linear correction value displacement based on the tunnel's design standards, operational data, and safety regulations. These thresholds act as a "ruler" to measure the tunnel's normal operating status. For example, the temperature gradient threshold is used to determine whether temperature fluctuations within the tunnel are abnormal. Simultaneously, the priority of each parameter is dynamically adjusted based on the tunnel's structural safety level. For example, tunnels with higher safety levels may have a higher priority for the strain mutation threshold, as abnormal structural strain may directly threaten tunnel safety. Based on the tunnel's segment-coded coordinates, the temperature distribution data, post-compensation strain values, signal attenuation rate, and linear correction value displacement for the same segment are integrated. During the integration process, accurate temporal and spatial alignment of these data is ensured. Accurate timestamps are added to each data point to generate a multidimensional dynamically correlated data set. Each data set contains the complete set of monitoring parameters for the corresponding tunnel segment at a specific moment, creating a detailed "health profile" for each tunnel segment. This data set is then run through a pre-defined decision logic to initially identify tunnel sections that may be at risk. Once the decision logic identifies a tunnel section at risk, the compensated strain data for the redundant optical cables in that section is extracted and compared with the strain data for the main optical cables. If the strain deviation between the main and redundant optical cables exceeds the preset tolerance, this indicates a possible local failure of the main optical cable. The coordinates of the failure location are recorded and output, alerting personnel for inspection. If the data fluctuation exceeds the tunnel's designed elastic deformation tolerance, this indicates not only a potential problem with the optical cables but also a risk to the tunnel structure itself. This risk is identified as a complex structural risk, further alerting personnel to potential danger. The system continuously monitors the warning status of each tunnel section. When a preset proportion (e.g., 30%) of tunnel sections trigger both water seepage and local deformation warnings, and the displacement of the corrected linear value exceeds the overall deformation threshold for multiple monitoring cycles, the tunnel is determined to be at risk of overall deflection and optical cable failure. An alert is immediately generated, notifying relevant personnel in a prominent manner so they can take timely action to address the crisis.

[0101] The system integrates multi-dimensional data including temperature, strain, signal attenuation, and linear correction values ​​to monitor tunnel conditions from various perspectives. Combined with predefined thresholds and decision logic, it comprehensively and accurately identifies risks such as water seepage, local structural deformation, and optical cable failure. This avoids the limitations of single-data monitoring and improves the accuracy and completeness of risk identification. The system dynamically adjusts the priority of monitoring parameters based on the tunnel's structural safety level, adapting the early warning system to the characteristics and needs of each tunnel. Flexible parameter adjustments ensure the most effective risk warnings for both newly built high-security tunnels and older, standard tunnels, enhancing the system's versatility and adaptability. Redundant optical cable data is used for verification. When an anomaly in the primary optical cable data is compared with the redundant data, it accurately determines whether it represents a cable failure or structural risk, effectively reducing the possibility of misjudgment. If significant risks of overall tunnel deflection or optical cable failure are detected, an alert is quickly generated. This timely notification allows personnel to take immediate emergency measures, ensuring the safety of the tunnel and its surroundings, and improving the efficiency of emergency response in tunnel operations and maintenance.

[0102] An embodiment of the present invention further provides a computing device comprising: a processor and a memory storing a computer program, wherein the computer program, when executed by the processor, executes the system described above. All implementations in the above system embodiments are applicable to this embodiment and can achieve the same technical effects.

[0103] The embodiment of the present invention further provides a computer-readable storage medium storing instructions, which, when executed on a computer, causes the computer to execute the above-described method. All implementations in the above-described system embodiment are applicable to this embodiment and can achieve the same technical effects.

[0104] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A comprehensive pipe gallery structure health monitoring system based on distributed optical fiber sensing, characterized in that: include: The laying module is used to lay waterproof and corrosion-resistant fiber optic sensor cables in the corridor structure, and set positioning reference points and coordinate calibration reference points in the top center area of ​​both ends of the corridor to build a linear reference system covering the entire length of the corridor; The acquisition module is used to connect the optical fiber sensing cable with the distributed optical fiber temperature measurement device and the distributed optical fiber strain measurement device, and collect the temperature distribution data and strain distribution data in the pipeline corridor based on the principles of Raman scattering and Brillouin scattering to form a monitoring data set; The compensation module is used to compensate the strain distribution data in real time by laying parallel optical cables with temperature compensation and combining the temperature distribution data to obtain compensated strain distribution data; The monitoring module is used to set up redundant monitoring nodes at the fiber optic cable joints and corrosion-prone areas based on the compensated strain distribution data and to seal the nodes with sealant to trigger the seal layer integrity detection instruction; The correction module is used to regularly detect signal attenuation data of optical fiber sensor cables based on optical time domain reflectometry. It also generates a linear correction value representing the overall deformation of the tunnel by calculating the propagation time offset of the optical signal between the two detection points, in combination with a linear reference system constructed using positioning reference points and coordinate calibration reference points. The early warning module is used to integrate temperature distribution data, compensated strain distribution data, signal attenuation data and linear correction values ​​into the monitoring platform. By analyzing abnormal temperature gradients, strain mutations, signal attenuation trends and changes in linear correction values, it can provide real-time early warning of the risks of water seepage in the pipeline corridor and local structural deformation and deviation.

2. The integrated pipe gallery structure health monitoring system based on distributed optical fiber sensing according to claim 1 is characterized in that: Connect the optical fiber sensing cable to the distributed optical fiber temperature measurement device and the distributed optical fiber strain measurement device. Based on the principles of Raman scattering and Brillouin scattering, the temperature distribution data and strain distribution data in the pipeline corridor are collected to form a monitoring data set, including: A distributed optical fiber temperature measurement device injects a pulsed optical signal with a preset pulse width and peak power into the optical fiber sensing cable, capturing the Stokes light and anti-Stokes light signals in the Raman backscatter in real time. Based on the light intensity ratio of the two and the preset temperature calibration relationship, it generates meter-level resolution temperature distribution data along the axial direction of the tunnel. During the injection of the pulsed optical signal, the distributed optical fiber strain device is synchronously triggered to transmit a frequency-sweep probe light to the same optical fiber sensing cable. The Brillouin frequency shift of each optical fiber point is measured by Brillouin optical time-domain reflectometry. Combined with the frequency shift-strain conversion coefficient, the original strain distribution data including temperature interference is generated. The temperature gradient data and the original strain distribution data are aligned in time and space, and millisecond-level synchronization timestamps are added to both. Based on the pre-set segmented coded coordinates of the optical fiber and cable corridor, the temperature data and strain data are matched segment by segment according to the spatial position to form a monitoring data set with temporal and spatial correlation.

3. The integrated pipe gallery structure health monitoring system based on distributed optical fiber sensing according to claim 2 is characterized in that: The strain distribution data is compensated in real time by laying temperature-compensated parallel optical cables and combining them with the temperature distribution data to obtain compensated strain distribution data, including: Inside the tunnel structure, a reference optical cable is laid parallel to the main sensing optical cable along its route. The two cables are spaced at a preset distance and fixed in the same way to ensure that the main and reference optical cables are at the same temperature. Based on the spatiotemporal correlation monitoring data set, the original strain values ​​at each spatial location of the main optical cable and the Brillouin frequency shift data of the corresponding reference optical cable are synchronously extracted. Through a preset coordinate mapping algorithm, the frequency shift data of the main optical cable and the reference optical cable are spatially aligned according to the corridor segment coding; For each spatial location point corresponding to the tunnel segment code, the difference in Brillouin frequency shift between the main optical cable and the reference optical cable is calculated. Considering the characteristic that the frequency shift of the reference optical cable is only caused by temperature changes, a frequency shift compensation value is generated to characterize the effect of temperature on the strain measurement of the main optical cable. According to the real-time temperature distribution data of the main optical cable, the frequency shift compensation amount is converted into a temperature-coupled strain component using the preset temperature-strain relationship parameter library, and the temperature-coupled strain component is dynamically deducted from the original strain distribution data of the main optical cable to obtain the strain distribution data after temperature compensation.

4. The integrated pipe gallery structure health monitoring system based on distributed optical fiber sensing according to claim 3 is characterized in that: For each spatial location point corresponding to the tunnel segment code, the difference in Brillouin frequency shift between the main optical cable and the reference optical cable is calculated. Considering the characteristic that the frequency shift of the reference optical cable is only caused by temperature changes, a frequency shift compensation value is generated to characterize the effect of temperature on the strain measurement of the main optical cable, including: At the spatial position points corresponding to the tunnel segment codes, a preset coordinate mapping algorithm is used to align the Brillouin frequency shift data of the main optical cable and the reference optical cable at the same spatial resolution. The reference optical cable is fixedly connected to a non-stressed support through an elastic isolation layer to isolate the reference optical cable from external mechanical strain, ensuring that the frequency shift only reflects the temperature change at the corresponding location. Based on the material consistency characteristics of the main optical cable and the reference optical cable, the corresponding relationship parameters between the temperature change and the frequency shift of the two are pre-determined through calibration, the frequency shift difference between the main optical cable and the reference optical cable is calculated, and the frequency shift component caused by temperature change in the main optical cable is extracted; The frequency shift component is used as a dynamic compensation amount. Combined with the real-time temperature data collected by the distributed optical fiber temperature measurement device, the correlation between the compensation amount and temperature change is verified. The main optical cable strain data is dynamically corrected by the preset temperature-frequency shift compensation coefficient to generate a frequency shift compensation amount that characterizes the influence of temperature on the main optical cable strain measurement.

5. The integrated pipe gallery structure health monitoring system based on distributed optical fiber sensing according to claim 4 is characterized in that: Based on the compensated strain distribution data, redundant monitoring nodes are set at the fiber optic sensing cable joints and corrosion-prone areas. The nodes are sealed with sealant to trigger the seal layer integrity detection instructions, including: Based on the compensated strain distribution data, the strain values ​​of the coding points of each section of the corridor are extracted. By setting the dynamic strain threshold, the high-risk corridor sections with strain value mutation amplitudes greater than the preset safety range are identified, and the coordinate set of the abnormal area is generated. For the coordinate set of the abnormal area, two redundant sensor optical cables are laid in parallel at a preset interval along the laying path of the main sensor optical cable in the corresponding tunnel segment; For the joints of the main optical cable and redundant optical cable in the abnormal area, first scrape off the oxide layer on the joint surface, then wrap waterproof tape to cover the metal connection parts, and finally pour waterproof sealant to form a sealing layer with a thickness greater than 5 mm. The sealing range extends to the inner wall of the adjacent pipe gallery to form a seamless bond; The compensated strain data of the main optical cable and the redundant optical cable are collected synchronously in real time. When the deviation between the strain data of a certain section of the main optical cable and the redundant optical cable data is greater than the preset tolerance, the section is automatically marked as a cable failure risk section, and the redundant optical cable data is used as the monitoring basis to trigger the sealing layer integrity detection instruction.

6. The integrated pipe gallery structure health monitoring system based on distributed optical fiber sensing according to claim 5 is characterized in that: For optical fiber sensor cables, signal attenuation data is regularly detected based on optical time domain reflectometry. A linear reference system is constructed using positioning reference points and coordinate calibration reference points. By calculating the propagation time offset of the optical signal between the two detection points, a linear correction value representing the overall deformation of the tunnel is generated, including: The optical time domain reflectometer injects detection light pulses into the optical fiber sensor cable at a preset period, collects the backscattered signal of the entire cable section, extracts the signal attenuation intensity and attenuation rate per unit time at each tunnel segment coding point, and generates an attenuation feature data set including a timestamp; Based on the three-dimensional coordinates of the positioning reference points at both ends of the corridor and the geometric distribution of the coordinate calibration reference points, a linear spatial coordinate system based on the corridor axis is constructed. By calibrating the correspondence between the optical signal propagation time and the actual length of the corridor, a mapping table between time and spatial position is established, in which the propagation time of each corridor segment coding point accurately corresponds to the spatial coordinate. Compare the current attenuation feature dataset with the propagation time data of the initial reference period. Calculate the propagation time offset of the optical signal from the start point to the end point for the segmented code detection points at both ends of the same tunnel. Convert the time offset into axial deformation displacement based on a mapping table between time and spatial position. A weighted linear fitting analysis is performed on the axial deformation displacement of all tunnel segments. After eliminating abnormal displacement data that deviates from the overall trend, a straight line correction value representing the overall deformation of the tunnel is generated, including deformation direction, displacement and displacement fluctuation range parameters.

7. The integrated pipe gallery structure health monitoring system based on distributed optical fiber sensing according to claim 6 is characterized in that: Integrate temperature distribution data, compensated strain distribution data, signal attenuation data, and linear correction values ​​into the monitoring platform. By analyzing abnormal temperature gradients, sudden strain changes, signal attenuation trends, and linear correction value changes, it provides real-time warnings for risks of water seepage and local structural deformation in the pipeline corridor, including: The temperature gradient threshold, post-compensation strain mutation threshold, signal attenuation rate threshold, and linear correction value displacement tolerance range are set in the monitoring platform, and the priority relationship of each parameter is dynamically adjusted according to the safety level of the tunnel structure; Based on the corridor segment coding coordinates, the temperature distribution data, compensated strain values, signal attenuation rates, and linear correction value displacements of the same segment coding are spatiotemporally aligned to generate a multi-dimensional dynamic correlation data set including timestamps. Each data set corresponds to the complete monitoring parameters of a corridor segment, and decision logic is executed on the multi-dimensional dynamic correlation data set. Based on the judgment logic, redundant data verification is performed on the segments marked with risks, and the compensated strain data of the redundant optical cables is extracted. If the strain deviation between the main optical cable and the redundant optical cable is greater than the preset tolerance range, it is determined to be a local failure of the optical cable and the failure coordinates are output. If the fluctuation amplitude is greater than the allowable range of elastic deformation of the corridor design, it is determined to be a composite structural risk. When a tunnel segment larger than the preset ratio triggers water seepage and local deformation warnings at the same time, and the displacement of the linear correction value exceeds the overall deformation threshold for multiple cycles, it is determined that there is a risk of overall tunnel deviation and optical cable failure, and an alarm is generated.

8. The integrated pipe gallery structure health monitoring system based on distributed optical fiber sensing according to claim 7 is characterized in that: The decision logic includes marking it as a water seepage risk and triggering a level 1 alarm when the temperature gradient changes negatively and suddenly exceeds a threshold within a preset time, and the signal decay rate shows an upward trend over multiple detection cycles; If the strain value after compensation is greater than the threshold for multiple detection cycles, and the cumulative increase in the displacement of the linear correction value in the same direction is greater than the preset ratio of the tolerance range, it is determined to be a cumulative risk of local structural deformation and a secondary alarm is triggered.

9. A computing device, characterized in that include: one or more processors; A storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the system according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a program, which, when executed by a processor, implements the system according to any one of claims 1 to 8.

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