A lightweight monitoring system and evaluation method for the degradation degree of tunnel secondary lining structure

Abstract

The present application discloses a lightweight monitoring system and evaluation method for the degree of deterioration of the secondary lining structure of a tunnel. The evaluation method includes the following steps: constructing a concrete performance data set through finite element simulation based on the mechanical properties of concrete; training the concrete performance data set to obtain a concrete performance evaluation model; collecting temperature and longitudinal deformation data of each monitoring section in the tunnel; inputting the collected data into the concrete performance evaluation model for inversion to obtain elastic modulus evaluation values ​​of different monitoring sections of the tunnel; comparing the inversion results with the design standards to determine the degree of structural degradation of each monitoring section. The system is applied to the aforementioned evaluation method. The beneficial effects of the present application: using non-contact measurement, and taking sections as units, analyzing the relationship between longitudinal deformation and structural stiffness degradation, thereby locating sections of tunnels that are prone to or have already suffered from diseases, and conducting key monitoring. This process is low-cost, simple to operate, and can protect the entire tunnel section.

Description

Technical Field

[0001] The present application relates to the technical field of tunnel safety monitoring, and in particular to a lightweight monitoring system and evaluation method for the degree of degradation of a tunnel secondary lining structure. Background Art

[0002] There are currently three main non-contact tunnel monitoring methods, namely laser ranging technology, microwave radar ranging technology and visual ranging technology. Due to the uncertainty of the location of tunnel defects and the fact that all three ranging technologies belong to point monitoring, it is necessary to determine the location of the monitoring point by other means in advance before carrying out subsequent work.

[0003] In addition, distributed fiber optic monitoring is currently being developed. This method uses surface monitoring and can be deployed throughout the tunnel to accurately identify the specific location of the disease and the extent of structural damage. However, the cost is extremely high, and most of the tunnel structure does not have diseases, which will result in a large waste of resources and is currently difficult to promote on a large scale. Summary of the invention

[0004] One of the objects of the present application is to provide a lightweight monitoring system for the degradation degree of a tunnel secondary lining structure that can solve at least one of the defects in the above-mentioned background technology.

[0005] Another object of the present application is to provide a lightweight evaluation method for the degree of deterioration of a tunnel secondary lining structure that can solve at least one of the defects in the above-mentioned background technology.

[0006] In order to achieve at least one of the above purposes, the technical solution adopted in the present application is: a method for evaluating the degree of degradation of a tunnel secondary lining structure, comprising the following steps:

[0007] S100: Based on the mechanical properties of concrete, a concrete performance data set is constructed through finite element simulation; the concrete performance data set includes a temperature-deformation data set, a stress-strain data set, and an elastic modulus data set;

[0008] S200: Use deep learning methods to train the concrete performance data set to obtain a concrete performance evaluation model;

[0009] S300: Collecting temperature and longitudinal deformation data of each monitoring section in the tunnel;

[0010] S400: inputting the data collected in step S300 into the concrete performance evaluation model for inversion to obtain the actual elastic modulus of different monitoring sections of the tunnel;

[0011] S500: Compare the inversion result of step S400 with the design standard to determine the degree of structural degradation of each monitored section of the tunnel.

[0012] Preferably, after completing step S200, the obtained concrete performance evaluation model is corrected, including the following process: substituting the historical data of the temperature and longitudinal deformation of the tunnel as correction data into the concrete performance evaluation model; comparing the output result of the concrete performance evaluation model with the historical elastic modulus data of the tunnel; if the error between the two is less than or equal to a set threshold, it means that the obtained concrete performance evaluation model meets the accuracy requirements; if the error between the two is greater than the set threshold, performing error analysis and correcting the concrete performance evaluation model based on the historical data.

[0013] Preferably, when the tunnel concrete performance deteriorates to below the normal use limit state, it is determined to be in an abnormal state; in step S500, the monitoring section that is in an abnormal state and can be repaired and renovated is repaired and reinforced; after the reinforcement is completed, the strength improvement of the reinforced monitoring section is quantified through the concrete performance evaluation model.

[0014] A lightweight monitoring system for the degree of degradation of a tunnel secondary lining structure is applied to the above-mentioned method for evaluating the degree of degradation of a tunnel secondary lining structure; it comprises a plurality of monitoring points, a plurality of visual detection units and a plurality of temperature detection units; the tunnel is divided into a plurality of adjacent monitoring sections along the longitudinal length direction, and the monitoring points are arranged at the ends of the monitoring sections; the visual detection unit performs image acquisition corresponding to each of the monitoring points to obtain the longitudinal deformation of the monitoring section; the temperature detection unit is correspondingly installed at each of the monitoring sections to collect the surface temperature of the monitoring section.

[0015] Preferably, a target is installed at the monitoring point, and the visual detection unit is suitable for collecting images of the corresponding target, so as to obtain the longitudinal deformation amount of the corresponding monitoring section according to the change of the imaging size of the target.

[0016] Preferably, the visual detection unit is installed on a wall surface corresponding to the monitoring section, so that the visual detection unit can capture an image of the target installed on at least one end of the monitoring section.

[0017] Preferably, the visual detection unit is installed at one end of the monitoring section, so that the visual detection unit can capture images of the target installed at the other end of the monitoring section.

[0018] Preferably, a plurality of settlement joints are formed along the longitudinal length direction of the tunnel according to construction, and the monitoring section corresponds to the tunnel section between adjacent settlement joints.

[0019] Preferably, the tunnel is formed with a plurality of settlement joints along the longitudinal length direction according to the construction, the tunnel is divided into n sections according to the positions of the settlement joints, and the tunnel sections between adjacent settlement joints are divided into m sections, thereby obtaining n×m monitoring sections.

[0020] Preferably, a plurality of the monitoring points are provided at the end of the monitoring section, and the plurality of the monitoring points are arranged at equal intervals along the cross-sectional profile direction of the tunnel.

[0021] Compared with the prior art, the beneficial effects of this application are:

[0022] This application uses non-contact measurement to monitor the longitudinal strain of the tunnel and the ambient temperature in sections and establish a relationship. It also analyzes the relationship between the longitudinal deformation and the degradation of the structural stiffness in sections, thereby locating the sections where tunnel diseases are prone to or have occurred, and conducting key monitoring. This process is low-cost, simple to operate, and can protect the entire tunnel section. In combination with existing non-contact monitoring, it can achieve accurate positioning of tunnel damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the layout structure of the monitoring system in this application.

[0024] Figure 2 Schematic diagram of the principle of longitudinal deformation calculation performed by the visual detection unit in this application.

[0025] Figure 3 Schematic diagram of the specific workflow of the evaluation method in this application.

[0026] Figure 4 Schematic diagram of the modification process of the concrete performance evaluation model in this application. DETAILED DESCRIPTION

[0027] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0028] In the description of the present application, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of narrating the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific scope of protection of the present application.

[0029] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0030] The terms "including" and "having" and any variations thereof in the specification and claims of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0031] One aspect of the present application provides a lightweight monitoring system for the degradation degree of a tunnel secondary lining structure, such as Figure 1 As shown, one preferred embodiment includes multiple monitoring points, multiple visual detection units and multiple temperature detection units. When setting the monitoring points, the tunnel can be divided into multiple adjacent monitoring sections along the longitudinal length direction; then the multiple monitoring points can be set at the ends of each monitoring section. Each visual detection unit can collect image information of the corresponding monitoring point, and then the longitudinal deformation of each monitoring section can be obtained based on the collected image data. The temperature detection unit is installed in each monitoring section to collect the surface temperature of the monitoring section.

[0032] It should be known that the secondary lining of a tunnel refers to the secondary lining of the tunnel. The secondary lining and the initial support are relative. The secondary lining mainly refers to the inner lining built with materials such as concrete under the condition that the tunnel has been initially supported, in order to achieve the functions of strengthening support, optimizing route drainage system, beautifying appearance, facilitating the installation of communication, lighting, monitoring and other facilities, so as to meet the requirements of modern highway tunnel construction. Therefore, the structural strength of the secondary lining of the tunnel will affect the safety of the entire tunnel, and the monitoring of the tunnel is mainly the monitoring of the structural strength of the secondary lining of the tunnel.

[0033] It should be noted that the strength judgment basis of the tunnel secondary lining structure is mainly the elastic modulus E, and the factors affecting the elastic modulus are mainly temperature and longitudinal deformation; since the tunnel is generally a circular arch cross-section, the longitudinal deformation can also be regarded as axial deformation. Therefore, the monitoring of the strength of the tunnel secondary lining structure is mainly the monitoring of the surface temperature and longitudinal deformation of the tunnel. Since the length of the tunnel is generally long, in order to facilitate monitoring and improve the accuracy of monitoring, the tunnel can be divided into multiple sections along the longitudinal or axial length direction, so that multiple monitoring sections with relatively short lengths can be obtained. Then, a monitoring point can be set at the end position of each monitoring section for the visual detection unit to monitor the longitudinal deformation. The visual monitoring method is a non-contact method, which can effectively avoid the influence of tunnel deformation on the monitoring results to improve the monitoring accuracy. At the same time, a temperature detection unit is installed on each monitoring section for temperature collection. For each monitoring section, a temperature detection unit can be installed on the central surface of the monitoring section, or multiple temperature detection units can be installed at equal intervals along the longitudinal direction of the monitoring section.

[0034] It is understandable that the specific structure and working principle of the visual detection unit and the temperature detection unit are well-known technologies to those skilled in the art; common visual detection units include displacement monitoring camera devices such as gun cameras and ball cameras, and common temperature detection units include thermometers and temperature sensors. For the temperature detection unit, a thermometer can be used to capture the reading of the thermometer through a displacement monitoring camera and transmit the image data to the monitoring center for long-distance temperature data reading; for the temperature sensor, it can be directly transmitted to the monitoring center by signal transmission; the specific selection can be made according to the actual needs of those skilled in the art.

[0035] Specifically, this application uses non-contact measurement to monitor the longitudinal strain of the tunnel and the ambient temperature in sections and establish a relationship. It also analyzes the relationship between the longitudinal deformation and the degradation of the structural stiffness in sections, thereby locating the sections where tunnel diseases are prone to or have occurred, and conducting key monitoring. This process is low-cost, simple to operate, and can protect the entire tunnel section. In combination with existing non-contact monitoring, it can achieve accurate positioning of tunnel damage.

[0036] In this embodiment, Figure 1 As shown, in order to facilitate the visual detection unit to monitor the longitudinal deformation of the tunnel, a target can be installed at the detection point; the visual detection unit can capture a clear image by shooting the corresponding target. The visual detection unit can continuously capture images of the target; and then the longitudinal deformation of the corresponding monitoring section can be calculated based on the changes in the imaging size of the target in the images captured multiple times.

[0037] It should be known that the common way to directly monitor an object using a visual method is to directly collect the deformation of the object; specifically, the initial position of the monitoring point of the object can be marked, and then the monitoring point can move with the deformation of the object during the deformation of the object. At this time, the deformation of the object can be obtained by comparing the current position of the monitoring point with the marked position. However, in actual use, since the visual detection unit is always stationary, a certain deflection angle will be generated between the visual detection unit and the object during the deformation of the object, thereby affecting the accuracy of deformation collection; if you want to improve the accuracy, you need to use a corresponding algorithm to compensate, which will increase the calculation amount and cost of deformation collection, and the accuracy of the algorithm also directly affects the accuracy of deformation detection.

[0038] In this embodiment, the longitudinal displacement change from the target to the visual detection unit, i.e., the longitudinal deformation of the monitoring segment, can be obtained by reverse deduction based on the different image sizes of the target as the distance from the monitoring segment to the visual detection unit changes with the longitudinal deformation of the monitoring segment. For convenience, the following is a detailed description of the process of obtaining the longitudinal deformation of the monitoring segment by different target imaging sizes in this embodiment.

[0039] Specifically, Figure 2 As shown, the height of the target can be set as H, the longitudinal distance between the target and the lens of the displacement monitoring camera is L+ΔL, and the distance from the lens of the displacement monitoring camera to the internal imaging element is l. Initially, the target can be represented by a solid line frame, and the image height size of the target in the internal imaging element of the displacement monitoring camera is x 0 . With the longitudinal deformation of the monitoring segment, the target can move synchronously with the deformation of the monitoring segment. At this time, the target can be represented by a dotted frame; assuming that the target is approaching the displacement monitoring camera, and the approaching distance is ΔL, that is, the longitudinal deformation of the monitoring segment, then the longitudinal distance from the target to the lens of the displacement monitoring camera is L. Correspondingly, the image height size of the target in the imaging element inside the displacement monitoring camera is x.

[0040] According to the geometric relationship, the following relationship can exist:

[0041] x 0 / l=H / (L+ΔL), x / l=H / L.

[0042] Transforming the above relationship, we can get: Hl = x 0 (L+ΔL), Hl=xL.

[0043] Then according to x 0 (L+ΔL)= xL, the calculation formula of longitudinal deformation ΔL can be simplified as: ΔL=[(x / x 0 )-l]L.

[0044] It should be known that, from the above calculation formula, the calculation of the longitudinal deformation of the monitoring section has nothing to do with the height of the target and the distance from the lens of the displacement monitoring camera to the imaging element, but is only related to the imaging height of the target and the longitudinal distance from the displacement monitoring camera to the target. This can effectively simplify the calculation process and avoid the influence of other factors on the calculation results, and can effectively improve the monitoring accuracy of the longitudinal deformation of the monitoring section.

[0045] It should be noted that in the above calculation process, the vertical distance from the target to the displacement monitoring camera is assumed to be constant; since the tunnel is a circular arch structure with strong compressive resistance, the tunnel can be regarded as having no deformation in the vertical direction. Therefore, there is only a change in the distance in the longitudinal direction between the target and the displacement monitoring camera, which can maintain a high accuracy of the calculation result and the calculation process is relatively simple.

[0046] Those skilled in the art should know that there are joints in the tunnel during construction, and the joints can be divided into settlement joints and construction joints. Among them, the settlement joints cannot realize the transfer of longitudinal deformation between two adjacent tunnel sections, so as to avoid the longitudinal deformation interference of the tunnel sections on both sides of the settlement joints. The construction joint is the joint surface where the concrete is poured successively, and the longitudinal deformation of the adjacent tunnel sections can be transferred. Therefore, when arranging the monitoring system of the present application, it is only necessary to consider the settlement joints of the tunnel. The setting distance of the settlement joints can be comprehensively considered according to the length of the tunnel, the cross-sectional form, the geological conditions, the design load and other conditions. Therefore, according to the setting distance of the settlement joints, the monitoring section division method of the tunnel can be mainly divided into the following two methods.

[0047] Method 1: For settlement joints with shorter distances, the tunnel section between adjacent settlement joints can be directly set as the monitoring section. Then, n-1 settlement joints are required to form n continuous monitoring sections in the tunnel. Generally speaking, the value of n is greater than 1.

[0048] Method 2: For settlement joints with a long distance, such as Figure 1 As shown, the tunnel can be first divided into n sections according to the number of settlement joints, and then the tunnel sections between adjacent settlement joints are divided into m sections according to appropriate lengths, so that the tunnel can have n×m monitoring sections.

[0049] It is understandable that both of the above two methods can meet the requirements of this application, and can be selected according to the actual needs of technicians in this field. The values ​​of n and m can be selected according to actual needs, for example Figure 1 As shown, the value of n is greater than 1, and the value of m is 3. The longitudinal deformation of the three monitoring sections corresponding to adjacent settlement joints can be marked as ΔL 1 , ΔL 2 and ΔL 3 , the corresponding temperatures are marked as ΔT 1 , ΔT 2 and ΔT 3 ; The elastic modulus corresponding to the three monitoring sections is E 1 、E 2 and E 3 , the elastic modulus is related to the ratio of the corresponding longitudinal deformation and temperature.

[0050] For ease of understanding, the following content will be described in detail using the above-mentioned method 2 as an example.

[0051] In this embodiment, based on the imaging relationship between the visual detection unit and the target, there are multiple ways to install the visual detection unit. For ease of understanding, two examples will be used for detailed description below.

[0052] Example 1: Figure 2As shown, the visual detection unit can be installed at any position on the wall corresponding to the monitoring section, so that the visual detection unit can collect images of the target installed at at least one end of the monitoring section.

[0053] It can be understood that the number of visual detection units generally corresponds to the number of monitoring sections. For the case where the tunnel section between adjacent settlement joints includes multiple monitoring sections, targets can be installed at both ends of each monitoring section, and two adjacent monitoring sections share a monitoring point at adjacent positions.

[0054] Then, the visual detection unit located between the monitoring segments can collect images of the target installed at one end of the monitoring segment, and in order to ensure that all monitoring segments are measured, the target positions for image collection in the two targets corresponding to each monitoring segment are consistent. At this time, the longitudinal deformation of a single monitoring segment can be obtained by summing the calculation results of two adjacent visual detection units.

[0055] Of course, the visual detection unit located between the monitoring sections can simultaneously capture images of the targets at both ends of the monitoring section, and the longitudinal deformation of the monitoring section can be obtained by adding the results of the image capture and reverse calculation of the targets at both ends by the visual detection unit. In the current situation, the visual detection unit is preferably installed in the middle of the wall of the monitoring section so that the initial distance from the visual detection unit to the targets at both ends of the monitoring section is the same.

[0056] Example 2: The visual detection unit is installed at a monitoring point at one end of the monitoring section, so that the visual detection unit can collect images of the target installed at the monitoring point at the other end of the monitoring section.

[0057] It can be understood that the longitudinal deformation of the monitoring segment can be regarded as the change in distance between the monitoring points at both ends. Therefore, the visual detection unit can be installed at one end of the monitoring segment. In this way, when the monitoring segment undergoes longitudinal deformation, the change in distance between the visual detection unit and the monitoring point at the other end of the monitoring segment can be regarded as the longitudinal deformation of the monitoring segment.

[0058] In this embodiment, only one monitoring point can be set at the end of the monitoring section; however, considering that the stress conditions at various positions along the cross-sectional contour of the tunnel may be inconsistent, that is, the longitudinal deformation at various positions along the cross-sectional contour of the tunnel may be inconsistent. Therefore, in order to maintain the accuracy of the monitoring results, multiple monitoring points can be set at the end of each monitoring section, and the multiple monitoring points are set at equal intervals along the cross-sectional contour of the tunnel. A specific example is Figure 1 As shown, each monitoring section is provided with two monitoring points along the cross-sectional profile direction, and the two monitoring points are symmetrically arranged.

[0059] Another aspect of the present application provides a method for evaluating the degree of deterioration of a tunnel secondary lining structure, such as Figure 3As shown, one of the preferred embodiments includes the following steps:

[0060] S100: Based on the mechanical properties of concrete, a concrete performance data set is constructed through finite element simulation; the concrete performance data set includes a temperature-deformation data set, a stress-strain data set, and an elastic modulus data set.

[0061] S200: Use deep learning methods to train the concrete performance data set to obtain a concrete performance evaluation model.

[0062] S300: The temperature and longitudinal deformation data of each monitoring section in the tunnel are collected using the above-mentioned lightweight monitoring system for the degradation degree of the tunnel secondary lining structure.

[0063] S400: Input the data collected in step S300 into the concrete performance evaluation model for inversion to obtain elastic modulus evaluation values ​​of different monitoring sections of the tunnel.

[0064] S500: Compare the inversion result of step S400 with the design standard to determine the degree of structural degradation of each monitored section of the tunnel.

[0065] It can be understood that the above steps can be summarized into two parts: front-end data collection and tunnel status evaluation. Front-end data collection is mainly used to collect the surface temperature and longitudinal deformation, or axial deformation, of each monitoring section of the target tunnel. Tunnel status evaluation mainly involves building a concrete performance evaluation model, and then substituting the relevant data of the target tunnel collected by the front-end data into the concrete performance evaluation model to evaluate the structural performance of the target tunnel. For ease of understanding, a detailed explanation is given below.

[0066] Specifically, for the establishment of the concrete performance evaluation model; first, the finite element model of the tunnel concrete structure can be established in the finite element software based on the known mechanical properties of concrete. Then the temperature is used as the input of the model, and the deformation relationship is used as the output of the model; by listing as many temperature parameters as possible and inputting them into the model to output the corresponding deformation, a temperature-deformation data set including different temperatures and the deformations that match them can be obtained. Then the stress is used as the input of the model, and the deformation relationship is used as the output of the model; by listing as many stress parameters as possible and inputting them into the model to output the corresponding strain, a stress-strain data set including different stresses and the strains that match them can be obtained, and then the corresponding elastic modulus value can be calculated according to the ratio of stress to strain to obtain the elastic modulus data set. Finally, the obtained temperature-deformation data set, stress-strain data set and elastic modulus data set are summarized to obtain the required concrete performance data set.

[0067] It should be known that in the acquired concrete performance data set, for the deformation data generated by temperature and stress, only the lateral deformation of the concrete, that is, the longitudinal deformation, needs to be recorded. The acquired concrete performance data already includes the longitudinal deformation corresponding to the different temperatures and stresses that may occur during the use of the tunnel. Then, the concrete performance data set is trained through a deep learning model to obtain a concrete performance evaluation model, and the output of the concrete performance evaluation model is the elastic modulus E of the concrete structure.

[0068] For the front-end data collection of the target tunnel, the aforementioned lightweight monitoring system for the degradation degree of the tunnel secondary lining structure can be installed in the target tunnel, and the surface temperature and longitudinal deformation of each monitoring section in the tunnel can be collected according to the lightweight monitoring system for the degradation degree of the tunnel secondary lining structure. Then the collected data is input into the temperature-deformation data set of the concrete performance evaluation model for inversion, and the temperature-induced deformation corresponding to the temperature can be obtained, and then the longitudinal strain generated by the stress can be calculated by the difference between the collected longitudinal deformation and the temperature-induced deformation. Substitute the obtained longitudinal strain into the stress-strain data set of the concrete performance evaluation model for inversion again, and the corresponding stress value can be obtained. Then, according to the inverted stress value and the corresponding longitudinal strain, the elastic modulus evaluation value corresponding to each monitoring section of the target tunnel can be obtained. Finally, the degradation degree of the monitoring section is judged by comparing the obtained elastic modulus evaluation value with the design standard.

[0069] It is important to know that after the data collected by the lightweight monitoring system for the deterioration degree of the tunnel secondary lining structure is sent to the concrete performance evaluation model, the concrete performance evaluation model can use a table-like method to quickly match the input parameters with the concrete performance data set, and output the elastic modulus that has been calculated in advance according to the matched position, which can effectively improve the calculation speed of the model.

[0070] It should be known that the mechanical properties of concrete, that is, the initial elastic modulus E of concrete, can be obtained from the tunnel structure inspection report. The design standard of concrete can also be obtained from the tunnel structure inspection report. Generally speaking, the ultimate strength of the concrete structure that can operate normally can be used as the judgment threshold. Concrete structures with strengths lower than the ultimate strength of normal operation can be judged as abnormal, and vice versa.

[0071] In this embodiment, Figure 3 and Figure 4As shown, after completing step S200, the obtained concrete performance evaluation model is corrected, including the following process: substituting the historical data of the temperature and longitudinal deformation of the tunnel as correction data into the concrete performance evaluation model; comparing the output result of the concrete performance evaluation model with the historical elastic modulus data of the tunnel; if the error between the two is less than or equal to the set threshold, it means that the obtained concrete performance evaluation model meets the accuracy requirement; if the error between the two is greater than the set threshold, error analysis is performed and the concrete performance evaluation model is corrected based on the historical data.

[0072] It is understandable that the data in the concrete performance data set is obtained by finite element simulation, which is only theoretical deformation information obtained by theoretical calculation. In order to ensure that the obtained concrete performance evaluation model has sufficient accuracy, it is necessary to compare the actual value with the theoretical value to realize the correction of the concrete performance evaluation model. The historical data of the tunnel structure can be obtained from the tunnel structure monitoring report, and the temperature and deformation data of half a year to one year can be used as correction data.

[0073] In this embodiment, Figure 3 As shown, the tunnel secondary lining structure degradation degree evaluation method also includes a tunnel structure abnormality processing process. When the tunnel concrete performance deteriorates to below the normal use limit state, it is determined to be an abnormal state; in step S500, the monitoring section that is in an abnormal state and can be repaired and renovated is repaired and reinforced; after the reinforcement is completed, the strength improvement of the reinforced monitoring section is quantified through the concrete performance evaluation model.

[0074] It should be known that according to the tunnel structure inspection and monitoring report and the relevant specifications for the assessment of the technical status of tunnel on-site investigations, for tunnel structures in abnormal states, tunnel structures in abnormal states can be classified into three categories: C, D, and E through on-site investigations; the specific classification method is a well-known technology for those in this field, so it will not be elaborated in detail here. The degree of damage to Class C tunnel structures is moderate, that is, there is damage to the tunnel structure, but it develops slowly, which may affect the safety of pedestrians and vehicles. The degree of damage to Class D tunnel structures is severe damage, that is, there is relatively severe damage to the tunnel structure, which develops rapidly and has affected the safety of pedestrians and vehicles. Class E tunnel structures are in a dangerous state, that is, there is severe damage to the tunnel structure, which develops rapidly and has endangered the safety of pedestrians and vehicles.

[0075] For Class C tunnel structures, existing monitoring technologies can be used to design monitoring plans for their cross-sections, with a focus on monitoring structural defects. For Class D and E tunnel structures, timely maintenance and renovation are required; and after reinforcement, the tunnel status evaluation model needs to be used to re-quantify the strength improvement of the tunnel structure, and the results of the quantification should be used to determine whether the reinforced tunnel structure can meet the use requirements again.

[0076] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A method for evaluating the degree of deterioration of a tunnel secondary lining structure, characterized in that: The steps include: S100: Based on the mechanical properties of concrete, a concrete performance data set is constructed through finite element simulation; The concrete performance data set includes temperature-deformation data set, stress-strain data set and elastic modulus data set; S200: Use deep learning methods to train the concrete performance data set to obtain a concrete performance evaluation model; S300: Collecting temperature and longitudinal deformation data of each monitoring section in the tunnel; S400: inputting the data collected in step S300 into the concrete performance evaluation model for inversion to obtain elastic modulus evaluation values ​​of different monitoring sections of the tunnel; S500: comparing the inversion result of step S400 with the design standard to determine the degree of structural degradation of each monitoring section; Step S400 includes the following process: inputting the collected data into the temperature-deformation data set of the concrete performance evaluation model for inversion to obtain the temperature-induced deformation corresponding to the temperature, and then calculating the longitudinal strain generated by the stress through the difference between the collected longitudinal deformation and the temperature-induced deformation; The obtained longitudinal strain is substituted into the stress-strain data set of the concrete performance evaluation model for inversion again to obtain the corresponding stress value. Then, based on the inverted stress value and the corresponding longitudinal strain, the elastic modulus evaluation value corresponding to each monitoring section of the target tunnel is obtained.

2. The method for evaluating the degree of deterioration of the secondary lining structure of a tunnel according to claim 1, characterized in that: After completing step S200, the obtained concrete performance evaluation model is corrected, including the following process: Substitute the historical data of tunnel temperature and longitudinal deformation into the concrete performance evaluation model as correction data; Compare the output of the concrete performance evaluation model with the historical elastic modulus data of the tunnel; If the error between the two is less than or equal to the set threshold, it means that the obtained concrete performance evaluation model meets the accuracy requirements; If the error between the two is greater than the set threshold, an error analysis is performed and the concrete performance evaluation model is corrected based on historical data.

3. The method for evaluating the degree of deterioration of the secondary lining structure of a tunnel according to claim 1, characterized in that: When the tunnel concrete performance deteriorates to below the normal service limit, it is judged to be in an abnormal state; In step S500, the monitoring section that is in an abnormal state and can be repaired and modified is repaired and reinforced; After the reinforcement is completed, the strength improvement of the reinforced monitoring section is quantified through the concrete performance evaluation model.

4. A lightweight monitoring system for the degradation degree of a tunnel secondary lining structure, applied to the method for evaluating the degradation degree of a tunnel secondary lining structure according to any one of claims 1 to 3, characterized in that: The system comprises a plurality of monitoring points, a plurality of visual detection units and a plurality of temperature detection units; the tunnel is divided into a plurality of adjacent monitoring sections along the longitudinal length direction, and the monitoring points are arranged at the ends of the monitoring sections; the visual detection units collect images of the monitoring points to obtain the longitudinal deformation of the monitoring sections; the temperature detection units are correspondingly installed at the monitoring sections to collect the surface temperature of the monitoring sections.

5. The lightweight monitoring system for the degradation degree of the tunnel secondary lining structure according to claim 4 is characterized in that: The monitoring point is installed with a target, and the visual detection unit is suitable for collecting images of the corresponding target, so as to obtain the longitudinal deformation amount of the corresponding monitoring section according to the imaging size change of the target.

6. The lightweight monitoring system for the degradation degree of the tunnel secondary lining structure according to claim 5 is characterized in that: The visual detection unit is installed on a wall surface corresponding to the monitoring section, so that the visual detection unit can collect images of the target installed on at least one end of the monitoring section.

7. The lightweight monitoring system for the degradation degree of the tunnel secondary lining structure according to claim 6 is characterized in that: The visual detection unit is installed at one end of the monitoring section, so that the visual detection unit can collect images of the target installed at the other end of the monitoring section.

8. The lightweight monitoring system for the degradation degree of the tunnel secondary lining structure according to claim 4 is characterized in that: The tunnel is formed with a plurality of settlement joints along the longitudinal length direction according to construction, and the monitoring section corresponds to the tunnel section between adjacent settlement joints.

9. The lightweight monitoring system for the degradation degree of the tunnel secondary lining structure according to claim 4 is characterized in that: The tunnel is formed with a plurality of settlement joints along the longitudinal length direction according to the construction; the tunnel is divided into n sections according to the positions of the settlement joints, and the tunnel sections between adjacent settlement joints are divided into m sections, thereby obtaining n×m monitoring sections.

10. The lightweight monitoring system for the degradation degree of the tunnel secondary lining structure according to claim 4, characterized in that: A plurality of monitoring points are arranged at the end of the monitoring section, and the plurality of monitoring points are arranged at equal intervals along the cross-sectional profile direction of the tunnel.

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