A method and system for dynamic evaluation of a tunnel structure

Abstract

This invention provides a method and system for dynamic assessment of tunnel structures. The method includes the following steps: collecting multi-source monitoring data at risk monitoring sections within the tunnel; calculating a first state index reflecting structural stiffness degradation and a second state index reflecting the structure-seepage field coupling stability coefficient under the influence of seepage water; and calculating the comprehensive state index of the monitoring section at a target time using a preset dynamic assessment model to generate the corresponding structural state level and early warning information. By integrating multi-source heterogeneous monitoring data and constructing a dynamic assessment model, more accurate and forward-looking tunnel structure state perception and early warning can be achieved, overcoming the limitations of traditional single-threshold alarms. By calculating the structural stiffness degradation index and the seepage-structure coupling stability index, the attenuation of lining mechanical properties, groundwater seepage activity, and water corrosion effects are coupled and quantitatively assessed, significantly improving the accuracy of state judgment.

Description

Technical Field

[0001] This invention relates to the field of tunnel technology, and in particular to a method and system for dynamic evaluation of tunnel structures. Background Technology

[0002] As a critical node and vital engineering element in highway transportation networks, tunnels are subjected to the combined effects of multiple complex factors during long-term operation, including surrounding rock pressure, groundwater seepage, vehicle cyclic loads, and environmental erosion. As early-built tunnels enter the middle and later stages of their service life, structural defects such as lining cracking, water leakage, and material deterioration become increasingly prominent, directly threatening traffic safety and the service life of the tunnels.

[0003] In existing technologies, the structural condition assessment of operational tunnels mainly relies on periodic manual inspections, static alarm systems based on thresholds for single physical quantities (such as displacement and strain), or simple independent monitoring of multiple parameters. Manual inspections are highly subjective, inefficient, and cannot achieve continuous monitoring. Existing automated monitoring systems mostly compare isolated monitoring indicators with fixed thresholds, resulting in low alarm accuracy and a tendency to produce false alarms or missed alarms. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method and system for dynamic evaluation of tunnel structures, which aims to solve the technical problems of low monitoring efficiency and poor effect in the prior art.

[0005] To achieve the above objectives, in a first aspect, the present invention provides: a method for dynamic evaluation of tunnel structures, comprising the following steps: Multi-source monitoring data were collected at the risk monitoring section inside the tunnel. The multi-source monitoring data included lining strain value, clearance convergence value, arch settlement value, lining external water pressure value, and seepage pH value. Based on the lining strain data, the equivalent bending strain energy density of the monitoring section at the target time is calculated. Based on the net clearance convergence value and the crown settlement value, the equivalent generalized force of the monitoring section at the target time is calculated. Based on the equivalent bending strain energy density and the equivalent generalized force, a first state index reflecting the structural stiffness degradation is calculated. Based on the external water pressure value of the lining, the seepage pH value, and the first state index, a second state index reflecting the structural-seepage field coupling stability coefficient under the action of seepage water is calculated. The risk level of the section where the monitoring section is located is obtained. Based on the risk level, the first state index and the second state index are dynamically weighted and normalized. Combined with the changing trends of the first state index and the second state index, the comprehensive state index of the monitoring section at the target time is calculated through a preset dynamic evaluation model. Based on the preset threshold range to which the comprehensive state index belongs, the corresponding structural state level and early warning information are generated.

[0006] According to one aspect of the above technical solution, the steps for calculating the first state index reflecting structural stiffness degradation specifically include: Synchronous acquisition and temperature compensation preprocessing of lining strain data at each measuring point of the monitoring section; The equivalent bending strain energy density of the monitoring section at the target time is calculated based on the strain data after temperature compensation. The net convergence change value and the arch settlement change value of the monitoring section at the target time are obtained simultaneously to calculate the equivalent generalized force that characterizes the load effect of the current deformation state on the lining structure. The equivalent generalized compliance of the strain energy density required to generate the current load effect at the target time is calculated based on the equivalent bending strain energy density and the equivalent generalized force. Based on the equivalent generalized flexibility and the baseline flexibility of the monitoring section in a healthy state, a first state index reflecting the degradation of structural stiffness is calculated.

[0007] According to one aspect of the above technical solution, the steps for performing anomaly detection based on the extracted features specifically include: The formula for calculating the equivalent bending strain energy density is as follows: ; In the formula, For the equivalent bending strain energy density, The elastic modulus of the lining concrete. The strain value at time t for the i-th strain measurement point is after temperature compensation. The initial reference strain of the monitoring section is given by n, which is the number of strain gauges arranged at the monitoring section. The expression for calculating the equivalent generalized force is: ; In the formula, Where B is the equivalent generalized force, and B is the equivalent bending stiffness determined based on the tunnel lining design parameters. Let be the net airspace convergence change value at time t. Let be the change in arch subsidence at time t. The equivalent radius of the tunnel cross-section. This is the reference length for the lining thickness.

[0008] According to one aspect of the above technical solution, the formula for calculating the structural stiffness degradation index is: ; ; In the formula, For equivalent generalized flexibility, To monitor the baseline flexibility of the cross-section under healthy conditions, The structural stiffness degradation index is given.

[0009] According to one aspect of the above technical solution, the steps for calculating the second state index reflecting the stability coefficient of the structure-seepage field coupling under the action of seepage water specifically include: For the same high-risk monitoring section, the measured value of the external water pressure of the lining and the corresponding seepage pH value are extracted simultaneously at the current moment. The water pressure data is then subjected to validity verification and smoothing filtering preprocessing to eliminate instantaneous disturbances. The cumulative water pressure potential within a preset time window is calculated based on the measured water pressure value after pretreatment, and the material corrosion influencing factor is calculated based on the seepage pH value. The coupling threat level to the monitoring section is calculated based on the cumulative water pressure potential and the material corrosion factor. Based on the coupling threat level and reference pressure value, a second state index is obtained that reflects the stability coefficient of the structure-seepage field coupling under the action of seepage water.

[0010] According to one aspect of the above technical solution, the calculation expression for the cumulative water pressure potential is as follows: ; In the formula, The cumulative potential of the water pressure is N, where N is the number of data points within a preset time window T. This represents the average water pressure value within a preset time window. The empirical coefficient reflecting the weight of pressure fluctuation amplitude is used, where j is the index variable of the data sampling point. The measured value of the external water pressure of the lining at time j. and These are the maximum and minimum measured values ​​of water pressure within a preset time window, respectively. The formula for calculating the corrosion factor of the material is as follows: ; In the formula, Let t be the pH value of the leakage water collected at the monitoring section, and k and y be the corrosion influence coefficients based on the sensitivity of the lining material to acidic and alkaline environments, respectively. The formula for calculating the coupling threat level is: ; In the formula, The coupling threat level, It is a small positive constant.

[0011] According to one aspect of the above technical solution, the calculation expression for the structure-seepage field coupling stability coefficient is as follows: ; In the formula, The structure-seepage field coupling stability coefficient is given. This is a reference pressure value determined based on the water pressure resistance of the lining design or historical data.

[0012] According to one aspect of the above technical solution, the calculation expression for the comprehensive state index is as follows: ; ; In the formula, The comprehensive state index, and These are the first and second state indices after normalization. and The weights are dynamically assigned based on the risk level. + =1, This is the state trend decay factor. The trend sensitivity coefficient and These are the rates of change of the first and second state indices after normalization within a preset time window, respectively.

[0013] Secondly, this solution also provides a dynamic evaluation system for tunnel structures, including: The acquisition module is used to collect multi-source monitoring data at the risk monitoring section inside the tunnel. The multi-source monitoring data includes lining strain value, clearance convergence value, arch settlement value, lining external water pressure value, and seepage pH value. The calculation module is used to calculate the equivalent bending strain energy density of the monitoring section at the target time based on the lining strain data, and to calculate the equivalent generalized force of the monitoring section at the target time based on the net convergence value and the crown settlement value. The state index module is used to calculate a first state index reflecting the structural stiffness degradation based on the equivalent bending strain energy density and the equivalent generalized force, and to calculate a second state index reflecting the structure-seepage field coupling stability coefficient under the action of seepage water based on the lining external water pressure value, seepage pH value and the first state index. The comprehensive module is used to obtain the risk level of the section where the monitoring section is located, perform dynamic weight allocation and normalization processing on the first state index and the second state index based on the risk level, and calculate the comprehensive state index of the monitoring section at the target time by combining the changing trends of the first state index and the second state index through a preset dynamic evaluation model. The early warning module is used to generate corresponding structural status levels and early warning information based on the preset threshold range to which the comprehensive status index belongs.

[0014] According to one aspect of the above technical solution, the status indicator module is specifically used for: Synchronous acquisition and temperature compensation preprocessing of lining strain data at each measuring point of the monitoring section; The equivalent bending strain energy density of the monitoring section at the target time is calculated based on the strain data after temperature compensation. The net convergence change value and the arch settlement change value of the monitoring section at the target time are obtained simultaneously to calculate the equivalent generalized force that characterizes the load effect of the current deformation state on the lining structure. The equivalent generalized compliance of the strain energy density required to generate the current load effect at the target time is calculated based on the equivalent bending strain energy density and the equivalent generalized force. Based on the equivalent generalized flexibility and the baseline flexibility of the monitoring section in a healthy state, a first state index reflecting the degradation of structural stiffness is calculated.

[0015] According to one aspect of the above technical solution, the status indicator module is further used for: For the same high-risk monitoring section, the measured value of the external water pressure of the lining and the corresponding seepage pH value are extracted simultaneously at the current moment. The water pressure data is then subjected to validity verification and smoothing filtering preprocessing to eliminate instantaneous disturbances. The cumulative water pressure potential within a preset time window is calculated based on the measured water pressure value after pretreatment, and the material corrosion influencing factor is calculated based on the seepage pH value. The coupling threat level to the monitoring section is calculated based on the cumulative water pressure potential and the material corrosion factor. Based on the coupling threat level and reference pressure value, a second state index is obtained that reflects the stability coefficient of the structure-seepage field coupling under the action of seepage water.

[0016] Compared with existing technologies, the beneficial effects of this invention are as follows: By integrating multi-source heterogeneous monitoring data and constructing a dynamic evaluation model, more accurate and forward-looking tunnel structure status perception and early warning can be achieved, overcoming the limitations of traditional single-threshold alarms. By calculating the structural stiffness degradation index and the seepage-structure coupling stability index, the mechanical performance degradation of the lining, groundwater seepage activity, and water corrosion effects are coupled and quantitatively evaluated, significantly improving the accuracy of status judgment. At the same time, by introducing dynamic weights based on risk levels and attenuation factors reflecting deterioration trends, the evaluation results can adapt to the risk characteristics of different tunnel sections and promptly capture early signs of structural deterioration, realizing the transformation from "post-event alarm" to "pre-event early warning," and comprehensively improving the intelligent level of tunnel structure safety assurance and maintenance efficiency. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the dynamic evaluation method for tunnel structures in the first embodiment of the present invention. Figure 2 This is a structural block diagram of the tunnel structure dynamic evaluation system in the second embodiment of the present invention; The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0018] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0019] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] Example 1 Please see Figure 1The figure shows a flowchart of the tunnel structure dynamic evaluation method in the first embodiment of the present invention. As shown in the figure, the method includes the following steps: Step S100: Collect multi-source monitoring data at the risk monitoring section inside the tunnel. The multi-source monitoring data includes lining strain value, clearance convergence value, arch settlement value, lining external water pressure value, and seepage pH value.

[0022] Specifically, in this embodiment, vibrating wire strain gauges are installed on the surfaces of key stress-bearing parts (such as the arch crown and left and right arch waists) of the monitoring section to measure the micro-strain of the lining concrete surface; deformation monitoring equipment is arranged on the monitoring section. Typically, fixed targets are installed on the arch waists and crown on both sides of the tunnel, and corresponding laser rangefinders or machine vision measuring instruments are installed. The laser rangefinder accurately measures the distance change between the instrument and the target by emitting a laser beam towards the target and receiving the reflected signal, thereby calculating the relative displacement values ​​of the section in the horizontal direction (clearance convergence) and vertical direction (arch crown settlement); vibrating wire piezometers are pre-embedded or drilled at known seepage points, construction joints, or behind the lining. The permeable stone of the sensor is in direct contact with groundwater, senses the pore water pressure, and converts the pressure value into a frequency signal output. The data acquisition instrument reads this frequency and converts it into a water pressure value according to the sensor calibration coefficient; online pH sensors are deployed at the same seepage point where the piezometer is installed, or at the main outlet point. The sensor probe directly contacts the seepage water body to measure the hydrogen ion concentration index (pH value) of the water body in real time, and outputs data through digital interfaces such as RS485 to assess the chemical corrosivity of the seepage water to the lining concrete.

[0023] Step S200: Based on the lining strain data, calculate the equivalent bending strain energy density of the monitoring section at the target time; based on the net clearance convergence value and the crown settlement value, calculate the equivalent generalized force of the monitoring section at the target time. Specifically, the expression for calculating the equivalent bending strain energy density is: ; In the formula, For the equivalent bending strain energy density, The elastic modulus of the lining concrete. The strain value at time t for the i-th strain measurement point is after temperature compensation. The initial reference strain of the monitoring section is given by n, which is the number of strain gauges arranged at the monitoring section. The expression for calculating the equivalent generalized force is: ; In the formula, Where B is the equivalent generalized force, and B is the equivalent bending stiffness determined based on the tunnel lining design parameters. Let be the net airspace convergence change value at time t. Let be the change in arch subsidence at time t. The equivalent radius of the tunnel cross-section. The reference length is the lining thickness. The physical significance of the equivalent generalized force lies in its ability to "invert" the observed deformation into an equivalent load effect required to produce that deformation through structural geometry and stiffness characteristics, thus providing a bridge for establishing the constitutive relationship between deformation and strain energy. Through step S200, the original strain and displacement data of different dimensions are transformed into two intermediate characteristic quantities with clear mechanical meaning. and This provides data preparation for the next step of calculating the first state index reflecting the degradation of structural stiffness.

[0024] Step S300: Based on the equivalent bending strain energy density and the equivalent generalized force, calculate the first state index reflecting the structural stiffness degradation; based on the external water pressure value of the lining, the seepage pH value, and the first state index, calculate the second state index reflecting the structural-seepage field coupling stability coefficient under the action of seepage water.

[0025] The specific steps for calculating the first state index reflecting structural stiffness degradation include: Synchronous acquisition and temperature compensation preprocessing of lining strain data at each measuring point of the monitoring section; The equivalent bending strain energy density of the monitoring section at the target time is calculated based on the strain data after temperature compensation. The net convergence change value and the arch settlement change value of the monitoring section at the target time are obtained simultaneously to calculate the equivalent generalized force that characterizes the load effect of the current deformation state on the lining structure. The equivalent generalized compliance of the strain energy density required to generate the current load effect at the target time is calculated based on the equivalent bending strain energy density and the equivalent generalized force. Based on the equivalent generalized flexibility and the baseline flexibility of the monitoring section in a healthy state, a first state index reflecting the degradation of structural stiffness is calculated.

[0026] The formula for calculating the structural stiffness degradation index is as follows: ; ; In the formula, For equivalent generalized flexibility, To monitor the baseline flexibility of the cross-section under healthy conditions, The structural stiffness degradation index is given.

[0027] In a way that is easy to understand, the current equivalent generalized force is generated. The corresponding unit load effect needs to be stored within the lining section. The larger the strain energy density, the larger the equivalent generalized compliance value, the smaller the strain energy required to produce the same load effect, or it can be understood as the structure being more prone to deformation, i.e., the compliance of the structure increases and the stiffness decreases.

[0028] when When = 1, it indicates that the current structural flexibility is consistent with the healthy benchmark, and the stiffness has not degraded.

[0029] when When <1, it indicates the current equivalent compliance. If the value exceeds the benchmark, the structure becomes more "flexible," indicating a degradation in stiffness. The smaller the value, the more severe the degradation.

[0030] when A value greater than 1 indicates that the current structure is more "rigid" than the baseline state, which may be due to measurement fluctuations or the early completion of material shrinkage, and is usually considered a normal fluctuation.

[0031] The steps for calculating the second state index, which reflects the stability coefficient of the structure-seepage field coupling under the action of seepage water, specifically include: For the same high-risk monitoring section, the measured value of the external water pressure of the lining and the corresponding seepage pH value are extracted simultaneously at the current moment. The water pressure data is then subjected to validity verification and smoothing filtering preprocessing to eliminate instantaneous disturbances. The cumulative water pressure potential within a preset time window is calculated based on the measured water pressure value after pretreatment, and the material corrosion influencing factor is calculated based on the seepage pH value. The coupling threat level to the monitoring section is calculated based on the cumulative water pressure potential and the material corrosion factor. Based on the coupling threat level and reference pressure value, a second state index is obtained that reflects the stability coefficient of the structure-seepage field coupling under the action of seepage water.

[0032] The formula for calculating the cumulative potential of the water pressure is: ; In the formula, The cumulative potential of the water pressure is N, where N is the number of data points within a preset time window T. This represents the average water pressure value within a preset time window. The empirical coefficient reflecting the weight of pressure fluctuation amplitude is used, where j is the index variable of the data sampling point. The measured value of the external water pressure of the lining at time j. and These represent the maximum and minimum measured values ​​of water pressure within the preset time window, respectively.

[0033] In some application scenarios of this embodiment, the time series data of external water pressure of the lining in the past 24 hours are extracted, the average pressure within the window is calculated, and then the cumulative water pressure potential is calculated, which combines the fluctuation variance and range of water pressure. The larger the value, the more active the seepage field and the stronger the dynamic water pressure disturbance.

[0034] The formula for calculating the corrosion factor of the material is as follows: ; In the formula, Let t be the pH value of the leakage water collected at the monitoring section, and k and y be the corrosion influence coefficients based on the sensitivity of the lining material to acidic and alkaline environments, respectively. The formula for calculating the coupling threat level is: ; In the formula, The coupling threat level, These are small normal numbers. The aforementioned small normal numbers ensure that the evaluation model prevents the product from prematurely approaching zero when the structure is in a healthy or near-healthy state, and still maintains sensitivity to potential threats (water pressure fluctuations, water corrosion).

[0035] The formula for calculating the structure-seepage field coupling stability coefficient is as follows: ; In the formula, The structure-seepage field coupling stability coefficient is given. This is a reference pressure value determined based on the water pressure resistance of the lining design or historical data.

[0036] When coupling threat level When = 0, =1 indicates optimal stability; As the coupling threat level increases =1 indicates a decrease in stability.

[0037] when Approaching hour, A value approaching 0.5 indicates that the stability is in a critical state. > hour, <0.5 indicates significantly insufficient stability.

[0038] Step S400: Obtain the risk level of the section where the monitoring section is located; perform dynamic weight allocation and normalization processing on the first state index and the second state index based on the risk level; and calculate the comprehensive state index of the monitoring section at the target time by combining the changing trends of the first state index and the second state index through a preset dynamic evaluation model.

[0039] Preferably, the formula for calculating the comprehensive state index is: ; ; In the formula, The comprehensive state index, and These are the first and second state indices after normalization. and The weights are dynamically assigned based on the risk level. + =1, This is the state trend decay factor. The trend sensitivity coefficient and These are the rates of change of the first and second state indices after normalization within a preset time window, respectively.

[0040] The trend sensitivity coefficient is determined based on the pre-assessed top risk level of the section. For higher risk areas such as water-rich sections and tectonic fracture zones, the trend sensitivity coefficient is selected as 0.3-0.5; for medium-risk areas, it is 1.5-0.30; and for low-risk areas, it is 0.5-1.5. In the initial stage after the system is put into operation, the comprehensive status index of each section is observed. If it is found that the comprehensive status index of a high-risk section is lagging behind the development of obvious defects (such as accelerated convergence), the λ value is appropriately increased. Conversely, if a low-risk section frequently triggers false alarms due to fluctuations in normal data, the λ value is appropriately decreased.

[0041] In some application scenarios of this embodiment, the system retrieves the risk level of the monitored section from the pre-stored tunnel "section-risk level" mapping database based on the station number of the monitored section. This risk level is pre-classified based on the special investigation of the tunnel site area, geological exploration, historical disease data, and structural safety risk assessment report (risk assessment of sudden water inrush and tunnel entrance collapse), and is divided into levels such as "low risk", "moderate risk", and "relatively high risk".

[0042] Dynamic weights are assigned to the first and second state indicators based on the risk level of the call. and For areas with higher risk (water-rich sections, tectonic fracture zones), seepage-related risks are considered the primary threat; therefore, the second state index is given a higher weight, and is preferably... =0.7, =0.3; For low-risk sections, more attention is paid to the structural deformation stability itself, assigning a higher or balanced weight to the first state index, preferably 0.3; =0.6, =0.4.

[0043] Step S500: Generate the corresponding structural status level and early warning information based on the preset threshold range to which the comprehensive status index belongs.

[0044] Preferably, in this embodiment, 0.8≤ ≤1.0 corresponds to a structural status level of "healthy", and the warning information is registered as normal / no warning; 0.6≤ If the value is less than 0.8, the corresponding structural status level is "attention level", and the warning information is registered as a blue warning. 0.4≤ If the value is less than 0.6, the corresponding structural status level is "early warning status", and the early warning information is registered as a yellow warning. 0.2≤ If the value is less than 0.4, the corresponding structural status level is "alarm status", and the warning information is registered as an orange warning. 0 < A value less than 0.8 corresponds to a "state of emergency" structural status, and the warning information is registered as a red warning.

[0045] In summary, the tunnel structure dynamic assessment method in the above embodiments of the present invention, by integrating multi-source heterogeneous monitoring data and constructing a dynamic assessment model, can achieve more accurate and forward-looking tunnel structure status perception and early warning, overcoming the limitations of traditional single-threshold alarms. By calculating the structural stiffness degradation index and the seepage-structure coupling stability index, the degradation of lining mechanical properties, groundwater seepage activity, and water corrosion effects are coupled and quantitatively assessed, significantly improving the accuracy of status judgment. At the same time, the introduction of dynamic weights based on risk levels and attenuation factors reflecting deterioration trends enables the assessment results to adapt to the risk characteristics of different tunnel sections and promptly capture early signs of structural deterioration, realizing the transformation from "post-event alarm" to "pre-event warning," comprehensively improving the intelligent level of tunnel structure safety assurance and maintenance efficiency.

[0046] Example 2 A second embodiment of this application also provides a dynamic evaluation system for tunnel structures, which is used to implement the embodiments and preferred embodiments described herein, and will not be repeated hereafter. As used below, the terms "module," "unit," "subunit," etc., can refer to a combination of software and / or hardware that performs a predetermined function. Although the system described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0047] like Figure 2 As shown, the system includes: a data acquisition module 100, a calculation module 200, a status indicator module 300, a comprehensive module 400, and an early warning module 500.

[0048] The acquisition module 100 is used to acquire multi-source monitoring data at the risk monitoring section inside the tunnel. The multi-source monitoring data includes lining strain value, clearance convergence value, arch settlement value, lining external water pressure value, and seepage pH value. The calculation module 200 is used to calculate the equivalent bending strain energy density of the monitoring section at the target time based on the lining strain data, and to calculate the equivalent generalized force of the monitoring section at the target time based on the net convergence value and the crown settlement value. The state index module 300 is used to calculate a first state index reflecting the structural stiffness degradation based on the equivalent bending strain energy density and the equivalent generalized force, and to calculate a second state index reflecting the structure-seepage field coupling stability coefficient under the action of seepage water based on the lining external water pressure value, seepage pH value and the first state index. The comprehensive module 400 is used to obtain the risk level of the section where the monitoring section is located, perform dynamic weight allocation and normalization processing on the first state index and the second state index based on the risk level, and calculate the comprehensive state index of the monitoring section at the target time by combining the changing trends of the first state index and the second state index through a preset dynamic evaluation model. The early warning module 500 is used to generate the corresponding structural status level and early warning information based on the preset threshold range to which the comprehensive status index belongs.

[0049] Preferably, in this embodiment, the status indicator module 300 is specifically used for: Synchronous acquisition and temperature compensation preprocessing of lining strain data at each measuring point of the monitoring section; The equivalent bending strain energy density of the monitoring section at the target time is calculated based on the strain data after temperature compensation. The net convergence change value and the arch settlement change value of the monitoring section at the target time are obtained simultaneously to calculate the equivalent generalized force that characterizes the load effect of the current deformation state on the lining structure. The equivalent generalized compliance of the strain energy density required to generate the current load effect at the target time is calculated based on the equivalent bending strain energy density and the equivalent generalized force. Based on the equivalent generalized flexibility and the baseline flexibility of the monitoring section in a healthy state, a first state index reflecting the degradation of structural stiffness is calculated.

[0050] Preferably, in this embodiment, the status indicator module 300 is further used for: For the same high-risk monitoring section, the measured value of the external water pressure of the lining and the corresponding seepage pH value are extracted simultaneously at the current moment. The water pressure data is then subjected to validity verification and smoothing filtering preprocessing to eliminate instantaneous disturbances. The cumulative water pressure potential within a preset time window is calculated based on the measured water pressure value after pretreatment, and the material corrosion influencing factor is calculated based on the seepage pH value. The coupling threat level to the monitoring section is calculated based on the cumulative water pressure potential and the material corrosion factor. Based on the coupling threat level and reference pressure value, a second state index is obtained that reflects the stability coefficient of the structure-seepage field coupling under the action of seepage water.

[0051] It should be noted that the modules can be functional modules or program modules, and can be implemented in software or hardware. For modules implemented in hardware, the modules can reside in the same processor; or the modules can be located in different processors in any combination.

[0052] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for dynamic evaluation of tunnel structures, characterized in that, Includes the following steps: Multi-source monitoring data were collected at the risk monitoring section inside the tunnel. The multi-source monitoring data included lining strain value, clearance convergence value, arch settlement value, lining external water pressure value, and seepage pH value. Based on the lining strain data, the equivalent bending strain energy density of the monitoring section at the target time is calculated. Based on the net clearance convergence value and the crown settlement value, the equivalent generalized force of the monitoring section at the target time is calculated. Based on the equivalent bending strain energy density and the equivalent generalized force, a first state index reflecting the structural stiffness degradation is calculated. Based on the external water pressure value of the lining, the seepage pH value, and the first state index, a second state index reflecting the structural-seepage field coupling stability coefficient under the action of seepage water is calculated. The risk level of the section where the monitoring section is located is obtained. Based on the risk level, the first state index and the second state index are dynamically weighted and normalized. Combined with the changing trends of the first state index and the second state index, the comprehensive state index of the monitoring section at the target time is calculated through a preset dynamic evaluation model. Based on the preset threshold range to which the comprehensive state index belongs, the corresponding structural state level and early warning information are generated.

2. The method for dynamic evaluation of tunnel structures according to claim 1, characterized in that, The specific steps for calculating the first state index reflecting structural stiffness degradation include: Synchronous acquisition and temperature compensation preprocessing of lining strain data at each measuring point of the monitoring section; The equivalent bending strain energy density of the monitoring section at the target time is calculated based on the strain data after temperature compensation. The net convergence change value and the arch settlement change value of the monitoring section at the target time are obtained simultaneously to calculate the equivalent generalized force that characterizes the load effect of the current deformation state on the lining structure. The equivalent generalized compliance of the strain energy density required to generate the current load effect at the target time is calculated based on the equivalent bending strain energy density and the equivalent generalized force. Based on the equivalent generalized flexibility and the baseline flexibility of the monitoring section in a healthy state, a first state index reflecting the degradation of structural stiffness is calculated.

3. The method for dynamic evaluation of tunnel structures according to claim 2, characterized in that, The formula for calculating the equivalent bending strain energy density is as follows: ； In the formula, For the equivalent bending strain energy density, The elastic modulus of the lining concrete. The strain value at time t for the i-th strain measurement point is after temperature compensation. The initial reference strain of the monitoring section is given by n, which is the number of strain gauges arranged at the monitoring section. The expression for calculating the equivalent generalized force is: ； In the formula, Where B is the equivalent generalized force, and B is the equivalent bending stiffness determined based on the tunnel lining design parameters. Let be the net airspace convergence change value at time t. Let be the change in arch subsidence at time t. The equivalent radius of the tunnel cross-section. This is the reference length for the lining thickness.

4. The method for dynamic evaluation of tunnel structures according to claim 3, characterized in that, The formula for calculating the structural stiffness degradation index is as follows: ； ； In the formula, For equivalent generalized flexibility, To monitor the baseline flexibility of the cross-section under healthy conditions, The structural stiffness degradation index is given.

5. The method for dynamic evaluation of tunnel structures according to claim 4, characterized in that, The specific steps for calculating the second state index, which reflects the stability coefficient of the structure-seepage field coupling under the action of leakage water, include: For the same high-risk monitoring section, the measured value of the external water pressure of the lining and the corresponding seepage pH value are extracted simultaneously at the current moment. The water pressure data is then subjected to validity verification and smoothing filtering preprocessing to eliminate instantaneous disturbances. The cumulative water pressure potential within a preset time window is calculated based on the measured water pressure value after pretreatment, and the material corrosion influencing factor is calculated based on the seepage pH value. The coupling threat level to the monitoring section is calculated based on the cumulative water pressure potential and the material corrosion factor. Based on the coupling threat level and reference pressure value, a second state index is obtained that reflects the stability coefficient of the structure-seepage field coupling under the action of seepage water.

6. The method for dynamic evaluation of tunnel structures according to claim 5, characterized in that, The formula for calculating the cumulative potential of the water pressure is: ； In the formula, The cumulative potential of the water pressure is N, where N is the number of data points within a preset time window T. This represents the average water pressure value within a preset time window. The empirical coefficient reflecting the weight of pressure fluctuation amplitude is used, where j is the index variable of the data sampling point. The measured value of the external water pressure of the lining at time j. and These are the maximum and minimum measured values ​​of water pressure within a preset time window, respectively. The formula for calculating the corrosion factor of the material is as follows: ； In the formula, Let t be the pH value of the leakage water collected at the monitoring section, and k and y be the corrosion influence coefficients based on the sensitivity of the lining material to acidic and alkaline environments, respectively. The formula for calculating the coupling threat level is: ； In the formula, The coupling threat level, It is a small positive constant.

7. The method for dynamic evaluation of tunnel structures according to claim 6, characterized in that, The formula for calculating the structure-seepage field coupling stability coefficient is as follows: ； In the formula, The structure-seepage field coupling stability coefficient is given. This is a reference pressure value determined based on the water pressure resistance of the lining design or historical data.

8. The method for dynamic evaluation of tunnel structures according to claim 1, characterized in that, The formula for calculating the comprehensive state index is as follows: ； ； In the formula, The comprehensive state index, and These are the first and second state indices after normalization. and The weights are dynamically assigned based on the risk level. + =1, This is the state trend decay factor. The trend sensitivity coefficient and These are the rates of change of the first and second state indices after normalization within a preset time window, respectively.

9. A tunnel structure dynamic evaluation system for implementing the tunnel structure dynamic evaluation method according to any one of claims 1-8, characterized in that, include: The acquisition module is used to collect multi-source monitoring data at the risk monitoring section inside the tunnel. The multi-source monitoring data includes lining strain value, clearance convergence value, arch settlement value, lining external water pressure value, and seepage pH value. The calculation module is used to calculate the equivalent bending strain energy density of the monitoring section at the target time based on the lining strain data, and to calculate the equivalent generalized force of the monitoring section at the target time based on the net convergence value and the crown settlement value. The state index module is used to calculate a first state index reflecting the structural stiffness degradation based on the equivalent bending strain energy density and the equivalent generalized force, and to calculate a second state index reflecting the structure-seepage field coupling stability coefficient under the action of seepage water based on the lining external water pressure value, seepage pH value and the first state index. The comprehensive module is used to obtain the risk level of the section where the monitoring section is located, perform dynamic weight allocation and normalization processing on the first state index and the second state index based on the risk level, and calculate the comprehensive state index of the monitoring section at the target time by combining the changing trends of the first state index and the second state index through a preset dynamic evaluation model. The early warning module is used to generate corresponding structural status levels and early warning information based on the preset threshold range to which the comprehensive status index belongs.

10. The tunnel structure dynamic evaluation system according to claim 9, characterized in that, The status indicator module is specifically used for: Synchronous acquisition and temperature compensation preprocessing of lining strain data at each measuring point of the monitoring section; The equivalent bending strain energy density of the monitoring section at the target time is calculated based on the strain data after temperature compensation. The net convergence change value and the arch settlement change value of the monitoring section at the target time are obtained simultaneously to calculate the equivalent generalized force that characterizes the load effect of the current deformation state on the lining structure. The equivalent generalized compliance of the strain energy density required to generate the current load effect at the target time is calculated based on the equivalent bending strain energy density and the equivalent generalized force. Based on the equivalent generalized flexibility and the baseline flexibility of the monitoring section in a healthy state, a first state index reflecting the degradation of structural stiffness is calculated.

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