Longitudinal connecting plate type ballastless track cracking supporting layer upward arching monitoring device and method

Abstract

The invention provides a longitudinal connecting plate type ballastless track cracking supporting layer upward arching monitoring device and method, and the device comprises a structure deformation sensing optical fiber which is used for monitoring the deformation condition of a supporting layer; the temperature sensing optical fiber is used for monitoring the temperature change in the supporting layer; the lead optical fiber is used for connecting the sensing optical fiber to a data monitoring station; the data monitoring station comprises an optical fiber modulation-demodulation instrument and a monitoring system platform and is used for receiving, processing and analyzing monitoring data from the structural deformation sensing optical fiber; wherein the structure deformation sensing optical fiber and the temperature sensing optical fiber are tightly embedded in a groove formed in the edge of the upper side of a ballastless track structure supporting layer, and the structure deformation sensing optical fiber and the temperature sensing optical fiber are connected to the data monitoring station arranged on the ground through the lead optical fiber. According to the invention, large-range and continuous monitoring is realized through a distributed optical fiber sensing technology, and the problem of arch deformation monitoring caused by degradation of a CRTS II type roadbed supporting layer at any time can be solved.

Description

Technical Field

[0001] The present invention relates to the field of track engineering maintenance monitoring, and more specifically, to a monitoring device and method for the cracking and arching of the supporting layer of longitudinally connected slab ballastless tracks. Background Art

[0002] CRTS II type slab ballastless tracks have the characteristics of high smoothness, high stability, high durability, and less maintenance, and are widely used in China's high-speed railways. However, with the increase in operation time, more and more deteriorated inclined cracks have appeared in the subgrade supporting layer of the ballastless track, resulting in track arching, which seriously affects stability and safety. Moreover, due to the randomness and uncertainty of the deteriorated inclined crack problem of the supporting layer, it is difficult for the existing technology to accurately predict the specific location of the inclined crack arching. This leads to the need to invest a large amount of manpower, material resources, and financial resources in regular inspections and repairs during the track maintenance and management process, which not only increases the operation cost but also makes it difficult to ensure the safety and stability of the track.

[0003] At present, China already has some patents on the monitoring methods for the structural deformation of ballastless tracks, mainly using traditional monitoring methods such as displacement sensors and strain gauges. Patent CN115600077A discloses an intelligent power-free monitoring method for the arching deformation state of ballastless track slabs, which can realize the real-time prediction of the arching value and the separation value of the track slab, but can only monitor specific points or local areas, and it is difficult to achieve large-scale and continuous arching monitoring. Patent CN108759702A discloses a system and monitoring method for distributed monitoring of the arching of track slabs. Although it can realize the arching monitoring of track slabs over a relatively long range, due to the layout close to the side of the track slab, there are still problems with insufficient accuracy. By synthesizing the existing patents, it can be found that although the current patents on the deformation monitoring of ballastless tracks have solved the problem of real-time monitoring of ballastless track deformation to a certain extent, there are still problems of insufficient monitoring range or insufficient accuracy, and they cannot cope with the arching deformation problem caused by the deterioration of the subgrade supporting layer of CRTS II type slab ballastless tracks at any time.

[0004] The CRTS II type track slab is a precast track slab, and the railway engineering department stipulates that the track slab cannot be grooved. Therefore, it is necessary to find a new monitoring method that can not only meet the monitoring requirements but also not damage the integrity of the track slab. The distributed optical fiber sensing technology is a unique sensing method based on optical fibers, with the advantages of continuous monitoring, high precision, and real-time performance. By grooving the supporting layer and burying the distributed optical fiber, the arching monitoring of the inclined cracks in the supporting layer of the track structure can be realized. Summary of the Invention

[0005] In view of the technical problems existing in the prior art, the present invention provides a monitoring device and method for the cracking and arching of the continuous slab ballastless track support layer, which can achieve large-scale and continuous monitoring through distributed optical fiber sensing technology, and can solve the problem of arching deformation monitoring caused by the deterioration of the subgrade support layer of CRTS II type at any time.

[0006] According to a first aspect of the present invention, there is provided a monitoring device for the cracking and arching of the continuous slab ballastless track support layer, comprising:

[0007] A structural deformation sensing optical fiber for monitoring the deformation of the support layer;

[0008] A temperature sensing optical fiber for monitoring the temperature change in the support layer to correct the strain measurement error caused by temperature change;

[0009] A lead optical fiber for connecting the structural deformation sensing optical fiber and the temperature sensing optical fiber to a data monitoring station;

[0010] A data monitoring station, including an optical fiber modulation and demodulation instrument and a monitoring system platform, for receiving, processing, and analyzing the monitoring data from the structural deformation sensing optical fiber;

[0011] Wherein, the structural deformation sensing optical fiber and the temperature sensing optical fiber are tightly embedded in the grooves opened at the upper side edge position of the ballastless track structure support layer, and the structural deformation sensing optical fiber and the temperature sensing optical fiber are connected to the data monitoring station arranged on the ground through the lead optical fiber.

[0012] On the basis of the above technical solutions, the present invention can also be improved as follows.

[0013] Optionally, the structural deformation sensing optical fiber, the temperature sensing optical fiber, and the lead optical fiber are all distributed optical fiber sensors based on the Brillouin scattering principle.

[0014] Optionally, the structural deformation optical fiber sensor is buried inside the support layer concrete and forms a loop with the lead optical fiber.

[0015] Optionally, the structural deformation sensing optical fiber and the temperature sensing optical fiber are fixedly installed in the grooves chiseled on the upper side of the support layer by using optical fiber anchor fasteners and are tightly connected to the support layer concrete.

[0016] Optionally, the optical fiber anchor fastener is a stainless steel fastener, and forms an integral body with the structural deformation sensing optical fiber, the temperature sensing optical fiber, and the monitoring structure by applying epoxy resin colloid.

[0017] Optionally, the length and depth of the opened grooves are set according to the monitoring requirements, and the chiseling depth is controlled within a safe range to ensure the minimum impact on the track structure.

[0018] Optionally, the data monitoring station can collect, transmit, process, and analyze the monitoring data from the sensing optical fiber in real time, promptly detect the inclined crack problems in the supporting layer, and evaluate their impact on the stability of the track structure.

[0019] According to the second aspect of the present invention, there is provided a monitoring method for the cracking and arching of the supporting layer of a longitudinally connected slab ballastless track, which is applied to the above-mentioned monitoring device for the cracking and arching of the supporting layer of a longitudinally connected slab ballastless track. The monitoring method includes the following steps:

[0020] S1. Excavate a shallow trench along the line direction parallel to the track centerline at the upper edge position above the supporting layer of the CRTS II type slab ballastless track in the subgrade section.

[0021] S2. Clean the trench, lay a cushion layer, and lay a distributed optical fiber sensor.

[0022] S3. Check the loop of the optical fiber sensor through an optical fiber modulation and demodulation instrument.

[0023] S4. After the inspection, fix the optical fiber sensor and seal the upper layer of the supporting layer trench with a sealant.

[0024] S5. Establish a long-term data monitoring station for long-term monitoring.

[0025] Optionally, it further includes S6. Perform temperature correction on the monitoring data, including:

[0026] Synchronize data acquisition: Obtain the distributed temperature field data along the optical fiber layout path inside the supporting layer concrete in real time through the temperature sensing optical fiber, and simultaneously record the original strain data of the structural deformation sensing optical fiber.

[0027] Establish a temperature-strain compensation model: During the laboratory calibration stage, pre-determine the temperature sensitivity coefficient αT of the sensing optical fiber and determine the false strain value corresponding to each 1°C change in temperature.

[0028] Perform data decoupling calculation; Substitute the temperature change amount ΔT(x) collected by the temperature sensing optical fiber into the data decoupling formula to calculate the corrected pure mechanical strain value.

[0029] Dynamic calibration: During the night period without train load, dynamically correct the temperature sensitivity coefficient αT through temperature-strain correlation analysis to eliminate the coefficient drift caused by material aging.

[0030] Optionally, substituting the temperature change amount ΔT(x) collected by the temperature sensing optical fiber into the data decoupling formula is expressed as:

[0031] εtrue(x) = εmeasured(x) - αT·ΔT(x)

[0032] Among them, x is the spatial coordinate of the optical fiber, ε measured(x) is the original strain value containing temperature change, and ε true(x) is the corrected pure mechanical strain value.

[0033] Technical effects and advantages of the present invention:

[0034] The present invention provides a longitudinal connection plate type ballastless track cracked support layer arching monitoring device and method, which realizes large-scale and continuous monitoring through distributed optical fiber sensing technology, and can solve the problem of arching deformation monitoring caused by the deterioration of the subgrade support layer of CRTS II type at any time. By effectively integrating and long-term protecting the optical fiber sensors in the support layer, it is ensured that the sensors are not interfered by the external environment and can accurately capture deformation information. Through real-time acquisition, transmission, noise reduction, and extraction of deformation characteristics of the distributed optical fiber sensing signals, the inclined crack deformation of the support layer is monitored in real time and early warnings are issued in a timely manner, greatly reducing the maintenance cost of the ballastless track.

[0035] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will become obvious from the specification or be understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained through the structures pointed out in the specification, claims, and drawings. Description of the Drawings

[0036] Figure 1 It is a cross-sectional structural schematic diagram of the support layer distributed optical fiber monitoring device provided by the embodiment of the present invention;

[0037] Figure 2 It is a schematic diagram of the inclined crack arching of the optical fiber monitoring support layer provided by the embodiment of the present invention;

[0038] Figure 3 It is a schematic flow diagram of a longitudinal connection plate type ballastless track cracked support layer arching monitoring method provided by the embodiment of the present invention.

[0039] In the figure:

[0040] 1. Track slab; 2. Mortar layer;

[0041] 3. Support layer; 4. Groove;

[0042] 5. Structural deformation sensing optical fiber; 6. Temperature sensing optical fiber;

[0043] 7. Lead optical fiber; 8. Optical fiber anchor;

[0044] 9. Data monitoring station;

[0045] 2-1. Initial state of the structural deformation optical fiber sensing;

[0046] 2-2. Bending state of the structural deformation optical fiber sensing with the inclined crack arching of the support layer. Detailed implementation manners

[0047] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0048] An embodiment of the present invention proposes a monitoring scheme for the inclined cracking and upward arching of the supporting layer of the CRTS II type slab ballastless track based on distributed optical fiber sensing technology. The essence of this scheme is that, without damaging the integrity of the CRTS II type track slab 1, by precisely grooving on the supporting layer and embedding high-performance distributed optical fiber sensors therein. These optical fiber sensors can be continuously arranged along the entire length of the supporting layer to form one or more monitoring chains, achieving full coverage of the deformation of the supporting layer.

[0049] It can be understood that, based on the defects in the background technology, an embodiment of the present invention proposes a monitoring device for the inclined cracking and upward arching of the supporting layer of the slab ballastless track, specifically as Figure 1 shown, including: a structural deformation sensing optical fiber 5, a temperature sensing optical fiber 6, a lead optical fiber 7, and a data monitoring station 9;

[0050] The structural deformation sensing optical fiber 5 is used to monitor the deformation of the supporting layer;

[0051] The temperature sensing optical fiber 6 is used to monitor the temperature change in the supporting layer 3 to correct the strain measurement error caused by the temperature change;

[0052] The lead optical fiber 7 is used to connect the structural deformation sensing optical fiber 5 and the temperature sensing optical fiber 6 to the data monitoring station 9;

[0053] The data monitoring station 9 includes an optical fiber modulation and demodulation instrument and a monitoring system platform, and is used to receive, process, and analyze the monitoring data from the structural deformation sensing optical fiber;

[0054] The structural deformation sensing optical fiber 5 and the temperature sensing optical fiber 6 are fixedly and tightly embedded in the groove 4 opened at the upper side edge position of the supporting layer 3 of the ballastless track structure; the buried lengths of the structural deformation sensing optical fiber 5 and the temperature sensing optical fiber 6 can be set according to the actual situation on site. The structural deformation sensing optical fiber 5 and the temperature sensing optical fiber 6 are connected to the data monitoring station 9 arranged on the ground through the lead optical fiber 7.

[0055] The structural deformation sensing optical fiber 5, the temperature sensing optical fiber 6, and the lead optical fiber 7 are all distributed optical fiber sensors based on the Brillouin scattering principle.

[0056] The structural deformation sensing optical fiber 5 and the temperature sensing optical fiber 6 are fixedly installed in the chiseled groove 4 on the upper side of the supporting layer by the optical fiber anchor 8, and are tightly connected to the concrete of the supporting layer 3. The length of the excavated groove 4 can be set according to the monitoring requirements, the engineering quantity is controllable, and the chiseling depth should be controlled within 5 cm. At the same time, the materials required for the cushion layer are less, the engineering construction is simple, and the monitoring can be carried out for a long time and continuously.

[0057] The optical fiber anchor 8 is a stainless steel fastener, which can form an integral body with the sensing optical fiber and the monitoring structure by applying epoxy resin colloid to ensure the stability of the optical fiber and the effectiveness of the monitoring.

[0058] The structural deformation optical fiber sensor 5 is buried inside the concrete of the supporting layer 3 and forms a loop with the lead optical fiber 7. During the monitoring process, through the Brillouin scattering principle, the distributed optical fiber sensor will collect the deformation information of the supporting layer in real time and convert it into an optical signal for transmission. These optical signals can accurately reflect the deformation characteristics and trends of the supporting layer after passing through a dedicated signal processing system. By analyzing and processing the monitoring data, the inclined crack problem in the supporting layer 3 can be detected in time and its impact on the stability of the track structure can be evaluated.

[0059] After the project is completed, the optical fiber temperature sensor can effectively monitor the temperature change inside the structure. The collected temperature wavelength can be converted into other physical quantities to remove the influence of temperature on the strain wavelength. Through the formula ε actual = ε strain 8845k temperature × (P measured - P initial), the collected strain data and temperature wavelength can be calculated into the actual strain influence of the track structure deformation on the strain optical fiber, so as to remove the influence of temperature on the strain value.

[0060] The data monitoring station 9 includes an optical fiber modulation and demodulation instrument BOTDR and a monitoring system platform.

[0061] The optical fiber modulation and demodulation device BOTDR, with its convenient and efficient operation characteristics and reliable monitoring data quality, can flexibly respond to demands and go deep into the site at any time to perform data collection tasks.

[0062] The data monitoring station 9 can safely place the optical fiber modulation and demodulation instrument, the lead optical fiber 7, the monitoring system, etc. in it, thus realizing the function of long-term monitoring; when abnormal upward arching deformation appears in the monitored supporting layer 3 structure, it can also give an early warning and send an alarm text message to the track maintenance personnel, including the specific location and the amount of upward arching data, etc.

[0063] The monitoring device for inclined crack and upward arching of the supporting layer of CRTS II type slab ballastless track is specifically as Figures 1 to 2As shown in the figure, it includes: an excavation trench 4 at the upper edge of the support layer, a structural deformation sensing optical fiber 5, a temperature sensing optical fiber 6, a lead optical fiber 7, an optical fiber anchor 8, and a data monitoring station 9. The structural deformation sensing optical fiber 5 and the temperature sensing optical fiber 6 are laid in the excavation trench 4 at the upper side edge of the support layer, and are connected to the data monitoring station 9 arranged outside the line through the lead optical cable 7. The implementation steps are as follows:

[0064] In advance, in the laboratory, connect the structural deformation sensing optical fiber 5 and the lead optical fiber 7 in series, and the temperature sensing optical fiber 6 and the lead optical fiber 7 in series to form a loop, and check whether data can be collected. The temperature sensing optical fiber 6 can not only be used to remove the temperature influence later, but also monitor the temperature of the track support layer structure; in a season or time with relatively low temperature, use a grooving machine to construct the trench 4. At this time, the support layer structure is relatively stable and smooth, and is not affected by high temperature loads to produce upward arching; then lay a cushion layer at the bottom of the trench 4.

[0065] Lay the above-mentioned series-connected structural deformation sensing optical fiber 5 and temperature sensing optical fiber 6 in the trench 4, and use the anchor 8 to fix them inside the trench. Subsequently, check the tightness of each section of the fixed-point structural deformation sensing optical fiber 5 and temperature sensing optical fiber 6. For example, Figure 2 in the figure, the initial state 2-1 of the structural deformation optical fiber sensing and the bending state 2-2 of the structural deformation optical fiber sensing with the upward arching of the support layer due to diagonal cracks.

[0066] Connect the lead optical fiber 7 to the optical fiber modulation and demodulation instrument BOTDR, and conduct an initial monitoring test to determine whether the structural deformation sensing optical fiber 5 and the temperature sensing optical fiber 6 meet the requirements. Then use sealant to seal the upper layer of the support layer trench 4 to prevent subsequent rainwater intrusion and damage the durability of the track structure concrete; at the same time, set up a data monitoring station for long-term monitoring.

[0067] The structural deformation sensing optical fiber 5 and the temperature sensing optical fiber 6 have good mechanical properties and tensile and compressive properties, can be well connected with the concrete of the support layer 3, and deform synergistically, which is convenient for construction and has good stability and durability.

[0068] According to the first aspect of the present invention, an embodiment of the present invention provides a method for monitoring the diagonal crack and upward arching of the support layer of the CRTS II type slab ballastless track, as Figure 3 shown, including the following steps:

[0069] S1. Along the line direction at the upper edge position of the support layer of the CRTS II type slab ballastless track in the subgrade section, excavate a shallow trench parallel to the track center line;

[0070] S2. Then clean the trench, lay a cushion layer, and lay a distributed optical fiber sensor;

[0071] S3. Check the loop of the optical fiber sensor through the optical fiber modulation and demodulation instrument BOTDR;

[0072] S4. After the inspection, fix the fiber optic sensor and seal the upper layer of the trench in the support layer with sealant to prevent subsequent rainwater intrusion and damage the durability of the track structure concrete;

[0073] S5. Establish a long-term data monitoring station for long-term monitoring.

[0074] It also includes S6. Perform temperature correction on the monitoring data. This implementation step calculates the actual strain influence of the track structure deformation on the strain fiber optic through the collected temperature wavelength, so as to obtain accurate deformation data and remove the influence of temperature change on strain measurement.

[0075] Specifically, during the long-term monitoring process, temperature changes will cause the fiber optic sensor to produce thermal expansion and contraction effects, which will in turn cause the drift of the strain measurement value. To eliminate temperature interference, the following steps are used for temperature correction:

[0076] ① Synchronous data acquisition: Obtain the distributed temperature field data along the fiber optic layout path inside the support layer concrete in real time through the temperature sensing fiber optic, and at the same time record the original strain data (including the superposition value of temperature and mechanical strain) of the structural deformation sensing fiber optic;

[0077] ② Establish a temperature-strain compensation model: During the laboratory calibration stage, pre-determine the temperature sensitivity coefficient αT (unit: με / ℃) of the sensing fiber optic to determine the false strain value corresponding to every 1℃ change in temperature.

[0078] ③ Data decoupling calculation: Substitute the temperature change amount ΔT(x) collected by the temperature sensing fiber optic into the formula:

[0079] εtrue(x) = εmeasured(x) - αT·ΔT(x)

[0080] where x is the fiber optic spatial coordinate, εmeasured(x) is the original strain value including temperature change, and εtrue(x) is the corrected pure mechanical strain value.

[0081] ④ Dynamic calibration: During the night period without train load, dynamically correct αT through temperature-strain correlation analysis to eliminate the coefficient drift caused by material aging.

[0082] In summary, the monitoring scheme for the inclined crack and upward arch of the support layer of the CRTS II type slab ballastless track adopted in the embodiment of the present invention utilizes the unique advantages of the distributed fiber optic sensing technology to realize the effective monitoring of the inclined crack and upward arch of the support layer of the CRTS II type slab ballastless track, providing important technical support for the maintenance and management of the track structure.

[0083] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0084] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

[0085] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A monitoring device for cracked supporting layer of longitudinal slab ballastless track, characterized in that: include: Structural deformation sensing optical fiber, used to monitor the deformation of the supporting layer; Temperature sensing optical fiber, used to monitor temperature changes in the support layer; Lead optical fiber, used to connect the structural deformation sensing optical fiber and the temperature sensing optical fiber to the data monitoring station; A data monitoring station, including an optical fiber modem and a monitoring system platform, for receiving, processing and analyzing monitoring data from the structural deformation sensing optical fiber; The structural deformation sensing optical fiber and the temperature sensing optical fiber are tightly embedded in the groove opened at the upper edge of the ballastless track structure support layer, and the structural deformation sensing optical fiber and the temperature sensing optical fiber are connected to the data monitoring station arranged on the ground through the lead optical fiber.

2. The device for monitoring the cracked supporting layer of a longitudinal slab ballastless track according to claim 1 is characterized in that: The structural deformation sensing optical fiber, temperature sensing optical fiber and lead optical fiber are all distributed optical fiber sensors based on the Brillouin scattering principle.

3. The device for monitoring the cracked supporting layer of a longitudinal slab ballastless track according to claim 1 is characterized in that: The structural deformation optical fiber sensor is buried in the supporting layer concrete and forms a loop with the lead optical fiber.

4. The device for monitoring the cracked supporting layer of a longitudinal slab ballastless track according to claim 1 is characterized in that: The structural deformation sensing optical fiber and the temperature sensing optical fiber are fixedly installed in the groove chiseled on the upper side of the supporting layer by using optical fiber anchors, and are connected to the concrete of the supporting layer.

5. The device for monitoring the cracked supporting layer of a longitudinal slab ballastless track according to claim 4 is characterized in that: The optical fiber anchor is a stainless steel fastener, which is integrated with the structural deformation sensing optical fiber, the temperature sensing optical fiber and the monitoring structure by applying epoxy resin colloid.

6. The device for monitoring the cracked supporting layer of a longitudinal slab ballastless track according to claim 1 is characterized in that: The length and depth of the trench are set according to monitoring requirements, and the excavation depth is controlled within a safe range to ensure that the impact on the track structure is minimized.

7. The device for monitoring the cracked supporting layer of a longitudinal slab ballastless track according to claim 1 is characterized in that: The data monitoring station can collect, transmit, process and analyze the monitoring data from the sensing optical fiber in real time, timely discover the oblique crack problem in the supporting layer, and evaluate its impact on the stability of the track structure.

8. A method for monitoring the camber of a cracked supporting layer of a longitudinally connected slab ballastless track, applied to a device for monitoring the camber of a cracked supporting layer of a longitudinally connected slab ballastless track as claimed in any one of claims 1 to 7, characterized in that: The monitoring method comprises the following steps: S1. Excavate a shallow trench at the upper edge of the slab track support layer along the track direction and parallel to the track centerline; S2. Clean the trench, lay the cushion layer, and lay the distributed optical fiber sensor; S3. Check the fiber optic sensor loop through the fiber optic modem; S4. After the inspection is completed, the optical fiber sensor is fixed and the upper layer of the groove of the supporting layer is sealed with a sealant; S5. Establish long-term data monitoring stations for long-term monitoring.

9. A method for monitoring the camber of the cracked supporting layer of a longitudinal slab ballastless track according to claim 8, characterized in that: Also included is S6. performing temperature correction on the monitoring data, including: Synchronous data acquisition: The distributed temperature field data of the supporting layer concrete along the fiber optic layout path is obtained in real time through the temperature sensing fiber, and the original strain data of the structural deformation sensing fiber is recorded at the same time; Establish a temperature-strain compensation model: During the laboratory calibration phase, the temperature sensitivity coefficient αT of the sensing optical fiber is measured in advance to determine the false strain value corresponding to each 1°C change in temperature; Perform data decoupling calculation: Substitute the temperature change ΔT(x) collected by the temperature sensing optical fiber into the data decoupling formula to calculate the corrected pure mechanical strain value; Dynamic calibration: During the night time when there is no train load, the temperature sensitivity coefficient αT is dynamically corrected through temperature-strain correlation analysis to eliminate the coefficient drift caused by material aging.

10. A method for monitoring the camber of the cracked supporting layer of a longitudinal slab ballastless track according to claim 9, characterized in that: Substituting the temperature change ΔT(x) collected by the temperature sensing optical fiber into the data decoupling formula is expressed as: εTrue(x)=εMeasured(x)-αT·ΔT(x) Where x is the spatial coordinate of the optical fiber, εmeasured(x) is the original strain value including temperature variation, and εtrue(x) is the pure mechanical strain value after correction.

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