A method for evaluating the service performance of highway tunnels

Abstract

The present invention relates to the field of highway tunnel engineering technology, and in particular to a highway tunnel service performance evaluation method, comprising: obtaining basic data of a target highway tunnel; constructing a calculation model of the target highway tunnel based on the basic data to obtain the structural bearing capacity of the target highway tunnel; if the structural bearing capacity meets a preset condition, determining whether the ventilation volume of the target highway tunnel meets the preset condition; if the structural bearing capacity does not meet the preset condition, performing maintenance on the target highway tunnel; if the ventilation volume meets the preset condition, constructing a highway tunnel service performance evaluation index system; if the ventilation volume does not meet the preset condition, performing maintenance on the target highway tunnel; and calculating a service performance evaluation value of the target highway tunnel based on the highway tunnel service performance evaluation index system to obtain a service performance evaluation result of the target highway tunnel. The present invention can ensure the healthy operation and maintenance of highway tunnels and achieve full and long-life operation and maintenance of highway tunnels.

Description

Technical Field

[0001] The present invention relates to the technical field of highway tunnel engineering, and in particular to a method for evaluating the service performance of a highway tunnel. Background Art

[0002] As highway tunnels age, their service performance declines without appropriate measures. When tunnel performance falls below critical levels, accidents can occur at any time during operation, leading to a range of adverse consequences. Accurately and comprehensively evaluating tunnel service performance, determining a tunnel's current state, and identifying current risk factors are crucial for developing maintenance plans and submitting maintenance project reports during tunnel operation.

[0003] Existing research on the operational performance of highway tunnels has primarily focused on the structural bearing capacity of highway tunnels. There is no prioritization or hierarchy between service performance and structural bearing capacity, ignoring the fact that structural bearing capacity is a prerequisite for tunnel service. Analysis of the supply and demand air volume of tunnel ventilation systems has also not been conducted. Consequently, current evaluation methods for highway tunnel service performance are not scientific or comprehensive.

[0004] To this end, the present invention proposes a method for evaluating the service performance of highway tunnels, which aims to evaluate the status of highway tunnels in the current operation stage and propose corresponding treatment strategies based on the evaluation results, thereby ensuring the healthy operation and maintenance of highway tunnels and realizing full-life and long-life operation and maintenance of highway tunnels. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for evaluating the service performance of highway tunnels, which prioritizes and hierarchizes the three aspects of the structural bearing capacity of highway tunnels, the supply and demand air volume of the ventilation system, and the service performance of the tunnel. It clarifies that the analysis of the structural bearing capacity of highway tunnels and the supply and demand air volume of the ventilation system are the premise or basis for the analysis of the service performance of the tunnel, and proposes corresponding treatment strategies based on the evaluation results, thereby ensuring the healthy operation and maintenance of highway tunnels and realizing the full and long-life operation and maintenance of highway tunnels.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A highway tunnel service performance evaluation method comprising:

[0008] Obtain basic data of the target highway tunnel;

[0009] constructing a calculation model of the target highway tunnel based on the basic data to obtain the structural bearing capacity of the target highway tunnel;

[0010] If the structural bearing capacity satisfies a preset condition, determining whether the ventilation volume of the target highway tunnel satisfies the preset condition; and if the structural bearing capacity does not satisfy the preset condition, maintaining the target highway tunnel;

[0011] If the ventilation volume meets the preset conditions, a highway tunnel service performance evaluation index system is constructed; if the ventilation volume does not meet the preset conditions, maintenance is performed on the target highway tunnel;

[0012] The service performance evaluation value of the target highway tunnel is calculated according to the highway tunnel service performance evaluation index system to obtain the service performance evaluation result of the target highway tunnel.

[0013] Optionally, the basic data of the target highway tunnel includes: geological conditions, design and construction data, dynamic monitoring data and expert experience.

[0014] Optionally, constructing a calculation model of the target highway tunnel to obtain the structural bearing capacity of the target highway tunnel includes:

[0015] Based on the basic data, an initial calculation model is constructed using three-dimensional numerical software;

[0016] Assigning mechanical parameters to the surrounding rock in the initial calculation model and determining boundary conditions to obtain the calculation model;

[0017] According to the calculation model, the strain and stress cloud maps of the target highway tunnel are obtained to analyze the structural bearing capacity of the target highway tunnel, or the structural bearing capacity of the target highway tunnel is analyzed using a hybrid neural network to obtain the structural bearing capacity of the target highway tunnel.

[0018] Optionally, obtaining the strain and stress cloud map of the target highway tunnel to analyze the structural bearing capacity of the target highway tunnel includes:

[0019] Obtaining initial ground stress and determining an initial state or a reference state by calculating the stress of each grid or unit in the model;

[0020] Under the initial state or the reference state, performing excavation simulation and structural construction on the calculation model to obtain strain and stress cloud maps of the target highway tunnel;

[0021] A deformation stress analysis is performed based on the strain and stress cloud diagram to obtain the structural bearing capacity of the target highway tunnel.

[0022] Optionally, analyzing the structural bearing capacity of the target highway tunnel using a hybrid neural network includes:

[0023] The surrounding rock parameters are inverted using a hybrid neural network, the inverted surrounding rock parameters are input into the calculation model for solution, and numerical results are obtained to analyze the bearing capacity.

[0024] Optionally, the width of the initial calculation model is 3-5 times the tunnel clearance, the tunnel vault is the actual buried depth of the tunnel, and the tunnel vault is 2-3 times the tunnel net height.

[0025] Optionally, determining whether the ventilation volume of the target highway tunnel meets a preset condition includes:

[0026] Calculating the time it takes for a vehicle to pass through the target highway tunnel based on the length of the target highway tunnel and the vehicle speed;

[0027] Calculating the air supply volume of the tunnel ventilation system during the entire driving process of the vehicle in the tunnel based on the ventilation equipment of the target highway tunnel;

[0028] The air volume required by the driver and passengers of the vehicle during the entire driving process in the tunnel is calculated based on the time it takes the vehicle to pass through the target highway tunnel. The air supply volume is compared with the required air volume to determine whether the ventilation volume of the target highway tunnel meets the preset conditions.

[0029] Optionally, the highway tunnel service performance evaluation index system includes: first-layer indicators and second-layer indicators subordinate to the first-layer indicators;

[0030] The first-tier indicators include electromechanical facilities, tunnel structure, and drainage system;

[0031] The second-level indicators include ventilation facilities, lighting facilities and fire-fighting facilities subordinate to the electromechanical facilities, lining structures and inverted arch structures subordinate to the tunnel structure, and drainage ditches, tarpaulins and drainage pipes subordinate to the drainage system.

[0032] Optionally, calculating the service performance evaluation value of the target highway tunnel includes:

[0033] Using the analytic hierarchy process, the weights of the evaluation indicators at each level in the highway tunnel service performance evaluation index system are calculated;

[0034] Obtaining, based on the basic data, status values ​​of evaluation indicators at various levels in the highway tunnel service performance evaluation index system;

[0035] The service performance evaluation value is obtained by multiplying the status value of the evaluation index at each level by the corresponding weight.

[0036] Optionally, obtaining the service performance evaluation result of the target highway tunnel includes: taking different maintenance measures to maintain the target highway tunnel according to the service performance evaluation result of the target highway tunnel.

[0037] The beneficial effects of the present invention are as follows: the present invention proposes a method for evaluating the service performance of a highway tunnel, which prioritizes and hierarchizes the three aspects of the structural bearing capacity of the highway tunnel, the supply and demand air volume of the ventilation system, and the service performance of the tunnel, clarifies that the analysis of the structural bearing capacity of the highway tunnel and the supply and demand air volume of the ventilation system is the premise or basis for the analysis of the service performance of the tunnel, and proposes corresponding treatment strategies based on the evaluation results, thereby ensuring the healthy operation and maintenance of the highway tunnel and realizing the full and long-life operation and maintenance of the highway tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 This is a flow chart of a method for evaluating the service performance of a highway tunnel according to an embodiment of the present invention;

[0040] Figure 2 Schematic diagram of a calculation model according to an embodiment of the present invention;

[0041] Figure 3 Schematic diagram of a highway tunnel service performance evaluation index system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] Structural bearing capacity is the premise of service performance, so the bearing capacity of the tunnel structure should be evaluated first. Only after the tunnel structure bearing capacity meets the requirements, it is necessary to evaluate the service performance of the tunnel structure. After the tunnel structure bearing capacity meets the requirements, for super-long tunnels, it is also necessary to analyze the supply and demand air volume of the tunnel ventilation system. If the air supply volume of the highway tunnel ventilation system cannot meet the minimum air volume required by the drivers and passengers from the tunnel entrance to the exit, the drivers and passengers will face the risk of insufficient air or oxygen supply. That is, when the highway tunnel structure bearing capacity and the ventilation system supply and demand air volume analysis cannot meet the requirements, there is no need to evaluate the tunnel service performance. Therefore, if Figure 1 This embodiment provides a method for evaluating the service performance of a highway tunnel, including:

[0045] Obtain basic data of the target highway tunnel;

[0046] Based on the basic data, a calculation model of the target highway tunnel is constructed to obtain the structural bearing capacity of the target highway tunnel;

[0047] If the structural bearing capacity meets the preset conditions, then determine whether the ventilation volume of the target highway tunnel meets the preset conditions; if the structural bearing capacity does not meet the preset conditions, then perform maintenance on the target highway tunnel;

[0048] If the ventilation volume meets the preset conditions, a highway tunnel service performance evaluation index system is constructed; if the ventilation volume does not meet the preset conditions, the target highway tunnel is maintained;

[0049] According to the highway tunnel service performance evaluation index system, the service performance evaluation value of the target highway tunnel is calculated to obtain the service performance evaluation result of the target highway tunnel.

[0050] Furthermore, the basic data of the target highway tunnel includes: geological conditions, design and construction information, dynamic monitoring data and expert experience.

[0051] Specifically, basic data for highway tunnels primarily includes geological conditions, design and construction data, dynamic monitoring data, and expert experience. Geological conditions include the tunnel site's weather (such as rainfall), topography, lithology, geological structure, hydrogeology, and adverse geological conditions. Design and construction data include design documents and construction plans. Dynamic monitoring data includes real-time monitoring of structural deformation and stress during tunnel construction and operation, such as lining convergence, invert uplift, lining crack width, and crown settlement. Expert experience includes expert review opinions and scores assigned to qualitative parameters during project execution. Surrounding rock parameters can be obtained from geological survey reports, such as surrounding rock mechanical parameters (such as elastic modulus, Poisson's ratio, cohesion, etc.), groundwater level, special geological conditions (such as whether there are karst caves, geometric dimensions and positions of faults, etc.); tunnel cross-sectional dimensions can be obtained from design documents, such as tunnel burial depth, tunnel clearance dimensions (clear width and clear height), lining structure parameters (such as lining thickness, lining type, lining material, etc.), and invert arch structure parameters (such as invert arch thickness, invert arch material, etc.).

[0052] Furthermore, a calculation model of the target highway tunnel is constructed to obtain the structural bearing capacity of the target highway tunnel, including:

[0053] Based on the basic data, the initial calculation model is constructed using three-dimensional numerical software;

[0054] In the initial calculation model, mechanical parameters are assigned to the surrounding rock, and boundary conditions are determined to obtain the calculation model;

[0055] According to the calculation model, the strain and stress cloud maps of the target highway tunnel are obtained to analyze the structural bearing capacity of the target highway tunnel, or the structural bearing capacity of the target highway tunnel is analyzed using a hybrid neural network to obtain the structural bearing capacity of the target highway tunnel.

[0056] Furthermore, obtaining the strain and stress cloud diagram of the target highway tunnel to analyze the structural bearing capacity of the target highway tunnel includes:

[0057] By calculating the stress of each grid or unit in the model, the initial ground stress is obtained and the initial state or reference state is determined;

[0058] Under the initial or baseline state, perform excavation simulation and structural construction on the calculation model to obtain the strain and stress cloud map of the target highway tunnel;

[0059] Deformation stress analysis is performed based on the strain and stress cloud diagram to obtain the structural bearing capacity of the target highway tunnel.

[0060] Furthermore, the structural bearing capacity of the target highway tunnel is analyzed using the hybrid neural network, including:

[0061] The surrounding rock parameters are inverted using a hybrid neural network, the inverted surrounding rock parameters are input into the calculation model for solution, and the numerical results are obtained to analyze the bearing capacity.

[0062] Specifically, the highway tunnel structural bearing capacity analysis includes: using three-dimensional refined numerical simulation calculations (such as FALC, ABAQUS, GTSNX and ANSYS, etc.) to analyze the highway tunnel structural bearing capacity. There are two methods. The first method includes the following steps:

[0063] (1) The initial calculation model is constructed using three-dimensional numerical software. The model size is 3-5 times the tunnel clearance to eliminate the boundary effect of the model size. The tunnel vault is taken as the actual tunnel burial depth, and the tunnel vault is taken as 2-3 times the tunnel clearance height. Figure 2 As shown;

[0064] (2) Assigning corresponding mechanical parameters to the surrounding rock, such as cohesion, elastic modulus, and internal friction angle of the surrounding rock;

[0065] (3) Set the boundary conditions of the model. The top of the model is set as a free boundary, and the left, right, front, and back, and bottom are set as fixed constraint boundaries.

[0066] (4) Initial calculation of the model: by monitoring the stress of each grid or unit to obtain the stress of the entire model, and then infer the initial ground stress of the model to determine the initial state or benchmark state of the tunnel;

[0067] (5) In the initial or reference state, the tunnel excavation simulation is carried out and the model is run until the unbalanced force is less than 10 -3 ;

[0068] (6) Construction of tunnel structure and assigning corresponding mechanical parameters to the structure, such as lining structure, invert structure, etc.;

[0069] (7) After the tunnel structure is constructed, the surrounding rock and the structure interact with each other. During the numerical calculation process, the unbalanced force is monitored to determine whether the model has reached a relatively stable state. When the unbalanced force of the model is less than 10 -3 When , it is approximately considered that the model has reached a relatively balanced state of force;

[0070] (8) Obtain the strain and stress cloud diagram of the tunnel structure and perform deformation and stress analysis;

[0071] (9) Compare the deformation and stress thresholds of the tunnel structure to complete the evaluation of the tunnel structure's bearing capacity.

[0072] The second method includes the following steps:

[0073] (1) The calculation model is constructed using three-dimensional numerical software. The model size is 3-5 times the tunnel clearance to eliminate the boundary effect of the model size. The tunnel vault is taken as the actual tunnel burial depth, and the tunnel vault is taken as 2-3 times the tunnel clearance height. Figure 2 As shown;

[0074] (2) Assigning corresponding mechanical parameters to the surrounding rock, such as cohesion, elastic modulus, and internal friction angle of the surrounding rock;

[0075] Obtaining the corresponding mechanical parameters involves intelligently inverting surrounding rock parameters (such as elastic modulus, Poisson's ratio, and cohesion) using hybrid neural network deep learning techniques (such as fully connected recurrent neural networks (ANN-RNNs)) based on data from regular tunnel inspections, special tests, and long-term structural monitoring during tunnel operation. This results in more accurate and realistic surrounding rock parameters. These inverted rock parameters are then incorporated into the computational model for solution. Finally, the bearing capacity is evaluated and analyzed based on numerical results (such as internal forces, structural deformation, surrounding rock settlement, and structural cracks). This cycle repeats repeatedly. By simultaneously considering field monitoring data and physical mechanisms, the resulting results are more comprehensive, reasonable, and accurate. Using deep learning techniques to invert surrounding rock parameters based on field-measured data, the resulting data more accurately reflects the actual project conditions and is more accurate than data obtained through traditional engineering analogies, expert experience, and laboratory experiments. Compared to single-network technologies, hybrid neural network deep learning techniques offer enhanced deep learning and intelligent inversion capabilities, thus avoiding vanishing and exploding gradients.

[0076] In this embodiment, the hybrid neural network inputs include: structural monitoring data, such as structural displacement, structural strain, apparent defects (such as cracks, water leakage, honeycomb surface, etc.), contact pressure between the structure and the surrounding rock, compressive strength of the structure, internal voids of the structure, etc.; the output includes: cohesion, elastic modulus, internal friction angle, etc. of the surrounding rock.

[0077] If the bearing capacity of a highway tunnel structure does not meet regulatory requirements—that is, the structure cannot withstand the surrounding rock pressure—there is a high probability of structural collapse or collapse, posing a high risk. In this case, no further analysis is required and the tunnel's service performance status is directly assessed as Level 4. Traffic can be closed if necessary, and maintenance projects can be implemented to improve the tunnel's bearing capacity. For lining structures, measures such as arching, arch replacement, steel arch support, and corrugated sheeting can be adopted; for inverted arch structures, arch replacement and grouting can be adopted.

[0078] Furthermore, determining whether the ventilation volume of the target highway tunnel meets the preset conditions includes:

[0079] Calculate the time it takes for a vehicle to pass through the target highway tunnel based on the length and vehicle speed of the target highway tunnel;

[0080] Based on the ventilation equipment of the target highway tunnel, calculate the air supply volume of the tunnel ventilation system during the entire process of the vehicle driving in the tunnel;

[0081] The air volume required by the driver and passengers during the entire driving process of the vehicle in the tunnel is calculated based on the time it takes the vehicle to pass through the target highway tunnel. The air supply volume is compared with the required air volume to determine whether the ventilation volume of the target highway tunnel meets the preset conditions.

[0082] If the ventilation system in a highway tunnel cannot supply the minimum air volume required for drivers and passengers to travel from the tunnel entrance to the exit, they risk air or oxygen insufficiency. In this case, the tunnel's service performance status is directly assessed as Level 4 without further analysis. Traffic can be closed as needed, and maintenance measures can be implemented to improve the tunnel's ventilation capacity. This can include increasing the number of fans, increasing fan power, and optimizing fan layout.

[0083] Further, such as Figure 3 The highway tunnel service performance evaluation index system shown includes: first-level indicators and second-level indicators subordinate to the first-level indicators;

[0084] The first level of indicators includes electromechanical facilities, tunnel structure and drainage system;

[0085] The second level of indicators includes ventilation facilities, lighting facilities and fire-fighting facilities subordinate to mechanical and electrical facilities, lining structure and invert structure subordinate to tunnel structure, and drainage ditches, waterproof cloth and drainage pipes subordinate to drainage system.

[0086] Furthermore, the service performance evaluation value of the target highway tunnel is calculated including:

[0087] The analytic hierarchy process is used to calculate the weights of each level of evaluation indicators in the highway tunnel service performance evaluation index system;

[0088] Based on the basic data, the status values ​​of the evaluation indicators at each level in the highway tunnel service performance evaluation index system are obtained;

[0089] Multiply the status value of each level evaluation indicator by the corresponding weight to obtain the service performance evaluation value.

[0090] Specifically, the analytic hierarchy process is used for calculation, and the steps are as follows:

[0091] ① Construct a judgment matrix: For each layer of elements, determine the relative importance of each element through pairwise comparison, and express these judgments in matrix form; ② Calculate weights: Perform a consistency test on the judgment matrix. If it passes, calculate the maximum eigenvalue of the judgment matrix and its corresponding eigenvector. The eigenvector is the weight of the element at this layer relative to the previous layer; ③ Calculate the consistency ratio (CR): In order to check the consistency of the judgment matrix, it is necessary to calculate the consistency index (CI) and the random consistency ratio (CR). If CR < 0.1, it is considered that the judgment matrix has satisfactory consistency and the weight calculation is correct; ④ Calculate the combined weight: Starting from the bottom layer, the weights of the elements at each layer are combined layer by layer from bottom to top according to the hierarchical structure to calculate the combined weight of all elements relative to the overall goal.

[0092] Based on the basic data of highway tunnels, the status values ​​of each level of the evaluation index system are determined. When the evaluation index is a quantitative indicator, the minimum and maximum values ​​of the quantitative data are first used to program the data. The calculation formula is as follows, which facilitates data fusion with the qualitative data evaluation results.

[0093] (1),

[0094] In the formula: a represents the specific numerical value of the quantitative data; min represents the minimum value of the data; max represents the maximum value of the data; b represents the normalized value of the quantitative data, that is, the value range of b is (0-1). When a takes the minimum value, the normalized b value is 0, indicating that the importance of the data can be ignored; when a takes the maximum value, the normalized b value is 1, indicating that the importance of the data is the greatest.

[0095] When the evaluation index is a qualitative index, the expert questionnaire method can be used to combine the expert engineering experience and theoretical knowledge to evaluate the qualitative data. The evaluation standard adopts the (0-1) scoring method, that is, a value between 0 and 1 is used to express the importance of the qualitative data. 0 means that the importance of the data can be ignored, and 1 means that the importance of the data is the greatest. The larger the value, the more important the qualitative data, and vice versa.

[0096] The evaluation calculation can be obtained by multiplying the status value of each level evaluation index in the evaluation index system by the corresponding weight and then summing them up.

[0097] Furthermore, after obtaining the service performance evaluation results of the target highway tunnel, the following steps are performed: Based on the service performance evaluation results, different maintenance measures are taken to maintain the target highway tunnel. A highway tunnel service performance status grade and the strategies to be adopted are formulated, as shown in Table 1.

[0098] Table 1

[0099]

[0100] Condition analysis is conducted based on the evaluation results of highway tunnel service performance. When the evaluation result reaches Level II, the safety risk is high, requiring enhanced monitoring and routine maintenance. The results for other status levels are similar.

[0101] Example 1:

[0102] Step 1: Obtain basic data of highway tunnels;

[0103] Contact the project tunnel's construction unit, survey unit, design and construction unit, supervision unit, government departments, quality inspection station, and third-party service units to collect non-confidential materials, such as project approval documents, survey reports, design drawings, construction plans, supervision plans, scientific research completion reports, and third-party service materials. Specific data about the project tunnel was obtained from the relevant materials, such as the tunnel's single-center cross-section, a clear width of 8.8 m, a clear height of 7.25 m, a composite lining structure, 10 cm thick anchor-sprayed support for the initial support, 0.25 m thick C30 reinforced concrete for the secondary lining, and 0.5 m thick C25 reinforced concrete for the inverted arch structure. The surrounding rock grade is IV mudstone, with an elastic modulus of 20 GPa, a cohesion of 3.58 kPa, and an internal friction angle of 35 degrees. The tunnel has been in operation for 30 years since its completion and opening to traffic.

[0104] Step 2: Analysis of the structural bearing capacity of highway tunnels;

[0105] The structural bearing capacity of the highway tunnel was analyzed using refined three-dimensional numerical simulations (such as FALC, ABAQUS, GTSNX, and ANSYS). The results indicate that the current compressive strength of the project tunnel's lining is 55 MPa, the tensile strength is 5.3 MPa, and the flexural strength is 5.9 MPa. According to relevant regulatory requirements, the critical compressive strength, tensile strength, and flexural strength of the project tunnel's lining are 50.0 MPa, 4.9 MPa, and 5.0 MPa, respectively. This indicates that the stress state of the project tunnel's lining exceeds regulatory requirements and is unable to withstand the surrounding rock pressure. The tunnel's structural bearing capacity does not meet regulatory requirements, necessitating the tunnel closure, implementation of relevant measures, and reporting to the maintenance project.

[0106] Example 2:

[0107] Step 1: Obtain basic data of highway tunnels;

[0108] Contact the project tunnel's construction unit, survey unit, design and construction unit, supervision unit, government departments, quality inspection station, and third-party service units to collect non-confidential materials, such as project approval documents, survey reports, design drawings, construction plans, supervision plans, scientific research completion reports, and third-party service materials. Specific data about the project tunnel was obtained from the relevant materials, such as the tunnel's single-center cross-section, clear width of 8.8 m, clear height of 7.25 m, composite lining structure, 10 cm thick anchor-shotcrete primary support, 0.25 m thick C30 reinforced concrete secondary lining, 0.5 m thick C25 reinforced concrete inverted arch structure, Grade IV mudstone with an elastic modulus of 20 GPa, cohesion of 3.58 kPa, and internal friction angle of 35 degrees. The tunnel is 18.0 km long, with a design speed of 60 km / h, a ventilation system with an air supply capacity of 50 L / min, and the tunnel has been in operation for 10 years since its completion and opening to traffic.

[0109] Step 2: Analysis of the structural bearing capacity of highway tunnels;

[0110] The structural bearing capacity of the highway tunnel was analyzed using refined three-dimensional numerical simulations (such as FALC, ABAQUS, GTSNX, and ANSYS). The results indicate that the current lining structure of the project tunnel has a compressive strength of 45 MPa, a tensile strength of 3.5 MPa, and a flexural strength of 2.9 MPa. According to relevant regulatory requirements, the critical compressive strength values ​​of the project tunnel lining structure are 50.0 MPa, the tensile strength value is 4.9 MPa, and the flexural strength value is 5.0 MPa. This indicates that the stress state of the current lining structure of the project tunnel does not exceed the relevant regulatory requirements and has sufficient capacity to bear the surrounding rock pressure. The tunnel structure's bearing capacity meets regulatory requirements, ensuring safe operation of the tunnel.

[0111] Step 3: Calculation and analysis of highway tunnel ventilation volume;

[0112] Based on the tunnel length and vehicle speed, the time required for a vehicle to enter the tunnel from the entrance to the exit is calculated to be t=18km / 60(km / h)=0.3h=18min; based on the tunnel's ventilation equipment, the air supply volume of the tunnel ventilation system during the entire process of the vehicle driving in the tunnel is calculated to be Q=50L / min*18min=900L; assuming that a vehicle enters the tunnel with 5 people on board, and assuming that each person requires 25L of air per minute, the total required volume is Q=5*25L / min*18min=2250L; it is obvious that the air demand of the driver and passengers is far greater than the air supply volume of the tunnel ventilation system, indicating that the tunnel's ventilation system cannot guarantee the safe exit of the vehicle from the tunnel. If necessary, the tunnel can be closed, relevant measures can be taken, and the maintenance project should be reported.

[0113] Example 3:

[0114] Step 1: Obtain basic data of highway tunnels;

[0115] Contact the project tunnel's construction unit, survey unit, design and construction unit, supervision unit, government departments, quality inspection station, and third-party service providers to collect non-confidential materials, such as project approval documents, survey reports, design drawings, construction plans, supervision plans, scientific research completion reports, and third-party service materials. Specific data about the project tunnel was obtained from these materials, including the tunnel's single-center cross-section, 8.8 m clear width, and 7.25 m clear height. The lining structure utilizes a composite lining structure, with 10 cm thick initial support using bolt-and-spray support, 0.25 m thick secondary lining using C30 reinforced concrete, and 0.5 m thick C25 reinforced concrete for the inverted arch. The surrounding rock grade is IV mudstone, with an elastic modulus of 20 GPa, cohesion of 3.58 kPa, and an internal friction angle of 35 degrees. The tunnel is 18.0 km long, with a design speed of 60 km / h, a ventilation system with an air supply capacity of 200 L / min, and the tunnel has been in operation for 10 years since its completion and opening to traffic.

[0116] Step 2: Analysis of the structural bearing capacity of highway tunnels;

[0117] The structural bearing capacity of the highway tunnel was analyzed using refined three-dimensional numerical simulations (such as FALC, ABAQUS, GTSNX, and ANSYS). The results indicate that the current lining structure of the project tunnel has a compressive strength of 45 MPa, a tensile strength of 3.5 MPa, and a flexural strength of 2.9 MPa. According to relevant regulatory requirements, the critical compressive strength values ​​of the project tunnel lining structure are 50.0 MPa, the critical tensile strength values ​​are 4.9 MPa, and the critical flexural strength values ​​are 5.0 MPa. This indicates that the stress state of the current lining structure of the project tunnel does not exceed the relevant regulatory requirements and has sufficient capacity to bear the surrounding rock pressure. The tunnel structure's bearing capacity meets regulatory requirements, ensuring safe operation of the tunnel.

[0118] Step 3: Calculation and analysis of highway tunnel ventilation volume;

[0119] Based on the tunnel length and vehicle speed, the time required for a vehicle to enter the tunnel from the entrance to the exit is calculated to be t=18km / 60(km / h)=0.3h=18min. Based on the tunnel's ventilation equipment, the air supply volume of the tunnel ventilation system during the entire process of the vehicle's driving in the tunnel is calculated to be Q=200L / min*18min=3600L. Assuming that a vehicle enters the tunnel with 5 people on board, and assuming that each person requires 25L of air per minute, the total required volume is Q=5*25L / min*18min=2250L. Obviously, the air supply volume of the tunnel ventilation system is far greater than the air demand of the driver and passengers, indicating that the tunnel's ventilation system can fully ensure that the vehicle can safely exit the tunnel and ensure the safe operation of the tunnel.

[0120] Step 4: Evaluation of highway tunnel service performance;

[0121] (1) Establish an evaluation indicator system;

[0122] (2) Calculation of weights of evaluation indicators at each level:

[0123] The weight of each indicator is calculated using the hierarchical analysis method. The "1-9 scale method" is used to construct the comparative judgment matrix. The consistency index of the judgment matrix is ​​calculated and tested using formulas (2) and (3). After the consistency index test is passed, the weight of the indicator at the corresponding level is calculated.

[0124] (2),

[0125] Where, CI represents the consistency index of the judgment matrix; λ max represents the maximum eigenvalue of the judgment matrix; n represents the order of the judgment matrix.

[0126] (3),

[0127] Where CR represents the consistency coefficient. When CR is less than 0.1, the consistency test of the judgment matrix passes. RI represents the average consistency index closely related to the order of the judgment matrix. The values ​​are shown in Table 2.

[0128] Table 2

[0129]

[0130] Taking the secondary indicators of electromechanical facilities, tunnel structure and drainage system as an example, the judgment matrix is ​​constructed as follows:

[0131] (4),

[0132] The maximum eigenvalue λmax=3.0037, CI=0.0019, CR=0.0032<0.1, meeting the consistency condition, the index weight vector Q A-B=[0.582, 0.109, 0.309]. The factor weights for electromechanical facilities, tunnel structure, and drainage system are 58.2%, 10.9%, and 30.9%, respectively. Similarly, the weights for each indicator in the three-level indicator system can be calculated, as shown in Table 3.

[0133] Table 3

[0134]

[0135] (3) Obtaining the status values ​​of evaluation indicators at each level:

[0136] Combined with the basic data of highway tunnels, the status values ​​of evaluation indicators at each level are obtained and normalized. The results are shown in Table 4.

[0137] Table 4

[0138]

[0139] (4) Calculation of tunnel service performance evaluation results:

[0140] Combining the weights and status values ​​of evaluation indicators at each level, the evaluation results of tunnel service performance are calculated, as shown in Table 5.

[0141] Table 5

[0142]

[0143] The calculation results of each indicator are summed up, and the evaluation result of the tunnel service performance is 0.60.

[0144] Step 5: Analysis of highway tunnel treatment strategies.

[0145] Combining the classification and strategy analysis of highway tunnel service performance status, it can be seen that the status level of the project tunnel is Level III, which has a high safety risk. A real-time monitoring treatment strategy is required, that is, real-time monitoring of higher-risk equipment or structures in the tunnel indicator system is carried out, and maintenance plans are reported at the same time.

[0146] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for evaluating the service performance of a highway tunnel, characterized in that: include: Obtain basic data of the target highway tunnel; Constructing a calculation model of the target highway tunnel based on the basic data to obtain the structural bearing capacity of the target highway tunnel includes: Based on the basic data, an initial calculation model is constructed using three-dimensional numerical software; Assigning mechanical parameters to the surrounding rock in the initial calculation model and determining boundary conditions to obtain the calculation model; According to the calculation model, obtaining strain and stress cloud maps of the target highway tunnel to analyze the structural bearing capacity of the target highway tunnel, or analyzing the structural bearing capacity of the target highway tunnel using a hybrid neural network to obtain the structural bearing capacity of the target highway tunnel; If the structural bearing capacity satisfies a preset condition, determining whether the ventilation volume of the target highway tunnel satisfies the preset condition; and if the structural bearing capacity does not satisfy the preset condition, maintaining the target highway tunnel; Determining whether the ventilation volume of the target highway tunnel meets a preset condition includes: Calculating the time it takes for a vehicle to pass through the target highway tunnel based on the length of the target highway tunnel and the vehicle speed; Calculating the air supply volume of the tunnel ventilation system during the entire driving process of the vehicle in the tunnel based on the ventilation equipment of the target highway tunnel; calculating the air volume required by the driver and passengers of the vehicle during the entire process of driving in the tunnel based on the time it takes the vehicle to pass through the target highway tunnel, comparing the air supply volume with the air demand volume, and determining whether the ventilation volume of the target highway tunnel meets a preset condition; If the ventilation volume meets the preset conditions, a highway tunnel service performance evaluation index system is constructed; if the ventilation volume does not meet the preset conditions, maintenance is performed on the target highway tunnel; The service performance evaluation value of the target highway tunnel is calculated according to the highway tunnel service performance evaluation index system to obtain the service performance evaluation result of the target highway tunnel.

2. The highway tunnel service performance evaluation method according to claim 1, characterized in that: The basic data of the target highway tunnel include: geological conditions, design and construction data, dynamic monitoring data and expert experience.

3. The highway tunnel service performance evaluation method according to claim 1, characterized in that: Obtaining the strain and stress cloud diagram of the target highway tunnel to analyze the structural bearing capacity of the target highway tunnel includes: Obtaining initial ground stress and determining an initial state or a reference state by calculating the stress of each grid or unit in the model; Performing excavation simulation and structural construction on the calculation model in the initial state or the reference state to obtain strain and stress cloud maps of the target highway tunnel; A deformation stress analysis is performed based on the strain and stress cloud diagram to obtain the structural bearing capacity of the target highway tunnel.

4. The highway tunnel service performance evaluation method according to claim 1, characterized in that: The analysis of the structural bearing capacity of the target highway tunnel using a hybrid neural network includes: The surrounding rock parameters are inverted using a hybrid neural network, the inverted surrounding rock parameters are input into the calculation model for solution, and numerical results are obtained to analyze the bearing capacity.

5. The highway tunnel service performance evaluation method according to claim 1, characterized in that: The size width of the initial calculation model is 3-5 times of the tunnel clearance, the tunnel vault is the actual buried depth of the tunnel, and the tunnel vault is 2-3 times of the tunnel clear height.

6. The highway tunnel service performance evaluation method according to claim 1, characterized in that: The highway tunnel service performance evaluation index system includes: first-level indicators and second-level indicators subordinate to the first-level indicators; The first-tier indicators include electromechanical facilities, tunnel structure, and drainage system; The second-level indicators include ventilation facilities, lighting facilities and fire-fighting facilities subordinate to the electromechanical facilities, lining structures and inverted arch structures subordinate to the tunnel structure, and drainage ditches, tarpaulins and drainage pipes subordinate to the drainage system.

7. The highway tunnel service performance evaluation method according to claim 1, characterized in that: Calculating the service performance evaluation value of the target highway tunnel includes: Using the analytic hierarchy process, the weights of the evaluation indicators at each level in the highway tunnel service performance evaluation index system are calculated; Obtaining, based on the basic data, status values ​​of evaluation indicators at various levels in the highway tunnel service performance evaluation index system; The service performance evaluation value is obtained by multiplying the status value of the evaluation index at each level by the corresponding weight.

8. The highway tunnel service performance evaluation method according to claim 1, characterized in that: After obtaining the service performance evaluation result of the target highway tunnel, the method includes: taking different maintenance measures to maintain the target highway tunnel according to the service performance evaluation result of the target highway tunnel.

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