Three-dimensional parametric simulation calculation method for segment structure of tunneling machine

Abstract

The present invention relates to the design technology of segment for tunneling machine, and discloses a three-dimensional parametric simulation calculation method for the segment structure of tunneling machine, which solves the problems of complex manual modeling, low efficiency and time-consuming calculation existing in the existing tunneling machine segment modeling and simulation scheme based on a simplified three-dimensional model. The method includes: calling a model initialization command set to initialize the modeling environment, and calling a basic parameter command set to establish a basic parameter system; calling a load analysis command set to calculate the formation pressure on the segment to obtain the load on the segment; calling a structure modeling command set to construct a three-dimensional segment calculation model of the tunneling machine including nodes, beam elements and spring elements; calling a calculation analysis command set to automatically simulate and solve the three-dimensional segment calculation model and automatically output the calculation results; obtaining the calculation results, calling a reinforcement analysis module and a structural calculation report module to automatically obtain the recommended segment reinforcement information and the structural calculation report.

Description

Technical Field

[0001] The present invention relates to the design technology of segment for tunneling machine, and particularly to a three-dimensional parametric simulation calculation method for the segment structure of tunneling machine. Background Art

[0002] In the construction of underground projects, the shield construction technology is widely used in underground engineering projects under various complex geological conditions due to its small impact on the environment and high construction efficiency. As the core structure in shield construction, the design quality of the segment for tunneling machine is directly related to the overall stability and durability of the tunnel. The segment for tunneling machine is generally made of high-strength reinforced concrete materials and is assembled in segments to form a tunnel lining structure. Its mechanical properties, anti-deformation ability, durability and other characteristics are crucial for the safety of the tunnel. Facing the complex and changeable geological conditions, accurately simulating and evaluating the mechanical behavior of segments under different loading conditions is an important link that cannot be ignored in the design. Therefore, the research on the design and simulation analysis of segments for tunneling machine has become a hot topic in the current academic and engineering circles.

[0003] The existing modeling and simulation schemes for segments of tunneling machines are mainly divided into two types: two-dimensional models and three-dimensional models. Among them, although the two-dimensional model has a fast calculation speed, it is difficult to accurately reflect the true stress state of the segment; the three-dimensional model is divided into a refined three-dimensional model and a simplified three-dimensional model. Among them, although the refined three-dimensional model has a high accuracy, the modeling process is complex, with many parameters, high calculation costs and difficult to converge; in contrast, the simplified three-dimensional model simplifies the segment structure of the tunneling machine into beam elements and uses spring elements to simulate the connection between segments and the interaction between segments and the formation. Through reasonable simplification and parametric settings, it can not only ensure the calculation accuracy, but also has the characteristics of high calculation efficiency and flexible adjustable parameters. Therefore, the simplified three-dimensional model is currently widely used in the modeling and simulation analysis of segments for tunneling machines.

[0004] However, in the traditional technology of the modeling and simulation scheme for segments of tunneling machines based on the simplified three-dimensional model, its implementation mainly relies on manual definition and construction of the model to simulate the complex mechanical interaction between the segment structure of the tunneling machine and the formation. Its specific implementation process is as follows:

[0005] 1. Manual parameter definition and modeling

[0006] In this process, researchers manually define various parameters of the simplified three-dimensional model according to the actual needs of the shield tunnel project, including the stiffness characteristics of the segment structure, the spring stiffness between the formation and the segment, and the joint characteristics between segment rings. These parameters usually need to be set in combination with engineering experience, geological exploration data and design standards. The modeling process is usually carried out through professional modeling software and requires step-by-step adjustment and verification. The steps are as follows:

[0007] (1) Input structure parameters: Define the geometric dimensions, material properties, and cross-sectional properties of the segment.

[0008] (2) Set spring elements: According to the elastic modulus of the formation and soil properties, set the stiffness parameters of each spring element to simulate the interaction between the segment and the surrounding formation.

[0009] (3) Determine boundary conditions: Set the boundary conditions and external loads of the model, such as formation stress, groundwater pressure, and construction disturbance effects.

[0010] (4) Calibrate the model: Through multiple simulations and adjustments, optimize the model parameters to make the simulation results consistent with the expected engineering data or experimental results.

[0011] 2. Segmented beam elements and locally refined model

[0012] In this process, to improve the model accuracy, the shield tunnel segments are usually discretized into multiple beam elements, which are connected to springs with different stiffnesses to form a parametric finite element model. For complex working conditions, such as non-uniform formations or asymmetric load cases, local areas may be further refined for modeling to capture stress concentration and deformation behavior, suitable for analyzing local stress characteristics and sensitive areas.

[0013] 3. Static and dynamic simulation analysis

[0014] In this process, based on the constructed simplified three-dimensional model, researchers analyze the structural behavior of the shield tunnel during different construction stages and long-term operation through numerical simulation tools. It includes static analysis (such as structural stability and formation deformation) and dynamic analysis (such as construction disturbance effects and formation consolidation effects), which are often used to evaluate formation settlement, segment stress distribution, structural stability, etc., to assist engineering design and construction decisions.

[0015] The defects of the above traditional techniques for shield tunnel segment modeling and simulation based on simplified three-dimensional models include:

[0016] (1) Difficult artificial modeling and cumbersome operation

[0017] The entire modeling process requires a large amount of manual intervention. Especially during parameter setting and modeling, researchers need to comprehensively consider complex formation conditions, structural characteristics, and construction working conditions. Manually inputting and adjusting each parameter calculation formula not only takes time but also easily introduces human errors, resulting in inaccurate or unstable models. Especially in projects with complex formations and significant structural nonlinearity, it is difficult to achieve fast and accurate simulations through artificial modeling.

[0018] (2) Complex parameter adjustment and low efficiency

[0019] The parameterization process of the model involves a large number of interrelated variables, such as the segment stiffness, interface stiffness characteristics, and formation spring stiffness. Researchers need to gradually optimize these parameters to ensure that the model can reasonably reflect the stress and deformation characteristics in actual engineering. However, the parameter setting and model verification process is very time-consuming, especially when facing long-distance or deep-buried tunnel projects, with low efficiency and difficulty in meeting the rapid response requirements of the project.

[0020] (3) High computational complexity and large resource consumption

[0021] The setting of multiple simplified three-dimensional model units and the complex boundary conditions and formation interactions lead to complex simulation calculations, long calculation time, especially when high-precision simulation or multi-field coupling analysis is required, the computational resources consumed are huge. This also limits the application scope of the simulation method based on the simplified three-dimensional model in actual engineering, especially in occasions where rapid plan adjustment or real-time construction monitoring is needed, and it is difficult to meet the project progress and optimized design requirements.

[0022] In summary, the existing tunneling machine segment modeling and simulation solutions based on simplified three-dimensional models have problems such as difficult manual modeling, complex parameter adjustment, low efficiency, and high overall simulation calculation complexity, and it is difficult to meet the actual needs of rapid project decision-making and optimized design. These problems highlight the limitations of the model in practical applications and urgently require the improvement of modeling and simulation technologies to improve efficiency and accuracy. Summary of the Invention

[0023] The technical problem to be solved by the present invention is: to propose a three-dimensional parametric simulation calculation method for the tunneling machine segment structure, which solves the problems of complex manual modeling, low efficiency, and time-consuming calculation existing in the existing tunneling machine segment modeling and simulation solutions based on simplified three-dimensional models.

[0024] The technical solution adopted by the present invention to solve the above technical problems is:

[0025] A three-dimensional parametric simulation calculation method for the tunneling machine segment structure includes the following steps:

[0026] S1. Call the model initialization command set to initialize the modeling environment, and call the basic parameter command set to establish a basic parameter system including material property parameters, geometric feature parameters, and formation characteristic parameters;

[0027] S2. Call the load analysis command set to calculate the formation pressure on the segment and obtain the load on the segment;

[0028] S3. Call the structure modeling command set to construct a three-dimensional tunneling machine segment calculation model including nodes, beam elements, and spring elements;

[0029] S4. Call the calculation and analysis command set to perform automatic simulation solution processing on the 3D segment calculation model of the tunneling machine, and automatically output the calculation results;

[0030] S5. Obtain the calculation results, call the reinforcement analysis module and the structural calculation report module, and automatically obtain the recommended segment reinforcement information of the tunneling machine and the structural calculation report.

[0031] Further, in step S1, the calling of the model initialization command set to initialize the modeling environment includes:

[0032] Clear the historical data and define the current simulation file and title, initialize the simulation environment, set the international unit system and convert it to the cylindrical coordinate system.

[0033] Further, in step S1, the calling of the basic parameter command set to establish a basic parameter system including material property parameters, geometric feature parameters, and formation characteristic parameters includes:

[0034] Call the material parameter definition function command set to define the elastic modulus, density, and Poisson's ratio parameters of the segment;

[0035] Call the geometric feature parameter definition command set to define the outer diameter, ring width, wall thickness, number of segment blocks, total number of circumferential bolts, offset angle of the closure block, inner size of the closure block in the ring, inner size of the adjacent block in the ring, radial and tangential stiffness of the circumferential bolts, and bending stiffness of the circumferential bolts;

[0036] Call the formation characteristic parameter definition command set to define the segment burial depth, groundwater depth, ground surcharge, rock mass unit weight, rock mass grade, and recommended values of geotechnical design parameters.

[0037] Further, in step S2, the calling of the load analysis command set to calculate the formation pressure on the segment and obtain the loads on the segment includes:

[0038] Obtain the input geometric feature parameters and formation characteristic parameters, call the load calculation command set, and calculate the vertical earth pressure, lateral earth pressure, lateral water pressure, and formation resistance loads;

[0039] Obtain the global coordinate positioning data, call the global coordinate transformation command set, transform the local load components from the local coordinate system to the global coordinate system, and obtain the global load component values to make the load distribution conform to the actual stress conditions of the segment.

[0040] Further, in step S3, the calling of the structural modeling command set to construct a 3D segment calculation model of the tunneling machine including nodes, beam elements, and spring elements includes:

[0041] Obtain the input segment geometric structure parameters, call the node generation command set to automatically generate node coordinates and establish nodes;

[0042] Obtain the input material parameters, call the beam element generation command set, and assign corresponding parameters to the element attributes to establish beam elements for simulating the segment structure;

[0043] Call the segment circumferential and inter-ring generation command sets to create circumferential and inter-ring spring elements connected to the beam elements. Use the inter-ring radial spring element and inter-ring tangential spring element to simulate the tangential and radial properties of the inter-ring bolts, and use the circumferential bending-resistant spring element to simulate the circumferential bending-resistant property of the circumferential bolts;

[0044] Obtain the input soil layer parameters, call the foundation spring generation command set to generate foundation springs connected to the beam element nodes for simulating the interaction between the segments and the soil layer;

[0045] Obtain the calculated global load component values, call the load application command set, and apply the loads to the beam element nodes;

[0046] Call the constraint addition command set. Simulate the constraint effect of the stratum on the tunneling machine segments by constraining the horizontal and vertical displacements of the foundation spring nodes, and ensure that the top nodes of the segments are only affected by the vertical soil pressure by constraining the vertical displacement of the highest node of the beam element.

[0047] Further, in step S4, the call to the calculation and analysis command set performs automatic simulation and solution processing on the three-dimensional segment calculation model of the tunneling machine, and automatically outputs the calculation results, including:

[0048] Enter the solution module, set the type of simulation solution through static analysis for static analysis;

[0049] Control and process the nonlinear analysis through load step and sub-step settings;

[0050] Call the criterion command set to set the convergence criterion and start iterative calculation;

[0051] Obtain the calculation results of the beam element nodes and extract and process the displacement and internal force data;

[0052] Call the post-processing visualization command set, obtain the displacement and internal force data, and automatically output the internal force contour maps of the segment structure bending moment, shear force, axial force, and deformation structure.

[0053] Further, the control and processing of the nonlinear analysis through load step and sub-step settings includes:

[0054] Define the number of sub-steps in the load step to control the load application rate; set the time step increment to ensure the stability of the calculation process; adjust the load increment size to optimize the iterative calculation efficiency.

[0055] Further, the setting process of the convergence criterion includes:

[0056] Set the convergence criteria for force, displacement, moment, and rotation angle; define the allowable error range; adjust the convergence parameters.

[0057] Further, the iterative calculation includes: during the iteration process, optimize the iterative strategy; the ways to optimize the iterative strategy include: by activating the linear search function to improve the stability of the solution; by increasing the maximum number of equilibrium iterations to handle complex nonlinear problems; by adjusting the number of load sub-steps to achieve adaptive control of the calculation process.

[0058] Further, in step S5, the obtaining of the calculation results, calling the reinforcement analysis module and the structural calculation report module, and automatically obtaining the recommended segment reinforcement information and the structural calculation report of the tunneling machine include:

[0059] Obtain the generated displacement and internal force data, call the reinforced concrete reinforcement module to automatically analyze the data, and obtain the segment reinforcement data of the tunneling machine;

[0060] Obtain the model parameters, model displacement and internal force data, cloud diagram, and reinforcement data, call the structural calculation report generation module, and obtain the structural calculation report.

[0061] The beneficial effects of the present invention are:

[0062] (1) Simplify the modeling process and reduce the complexity of manual operations:

[0063] By introducing the integrated command set and function module set into the automated modeling, the present invention simplifies the construction process of the three-dimensional segment calculation model of the tunneling machine. Researchers only need to make a small amount of necessary input, and the system can automatically complete the model building and setting, reducing the manual operation steps and complexity, reducing the risk of human error, and improving the convenience and reliability of modeling.

[0064] (2) Optimize the parameterization process and improve the modeling and adjustment efficiency:

[0065] The present invention uses an optimization algorithm to realize the automatic calculation and adjustment of model parameters. Researchers only need to input key design parameters, such as the geometric dimensions of the segments and the basic characteristics of the strata, etc. The system will automatically generate spring stiffness, beam element parameters, etc. through the intelligent optimization algorithm, significantly improving the parameterization modeling efficiency and meeting the requirements of rapid response and adjustment in engineering.

[0066] (3) Improve the calculation efficiency and reduce resource consumption:

[0067] By optimizing the solution process, the present invention reduces the number of iterations in the non-linear analysis, improves the simulation calculation speed, realizes fast simulation, saves computing resources and time, and meets the requirements of scheme adjustment.

[0068] (4) Automatically generate the internal force results of the segment:

[0069] The present invention can automatically calculate and generate the internal force results such as the bending moment, shear force and axial force of the segment, avoiding the cumbersome manual calculation and manual operation process; after the simulation is completed, the system automatically outputs the key mechanical indexes, which is convenient for quickly analyzing and evaluating the structural performance of the segment of the tunneling machine, and provides a reliable mechanical basis for engineering design and construction.

[0070] In summary, the present invention will greatly improve the efficiency and accuracy of the parametric modeling and simulation process of the segment of the tunneling machine, and provide more efficient, intelligent and reliable technical support for the design and construction of complex tunnel projects. Description of the Drawings

[0071] Figure 1 It is a flow chart of the three-dimensional parametric simulation calculation method for the segment structure of the tunneling machine in the present invention.

[0072] Figure 2 It is a schematic diagram of the three-dimensional segment calculation model of the tunneling machine based on the simplified three-dimensional model.

[0073] Figure 3 It is a process diagram of the three-dimensional parametric simulation calculation of the segment structure of the tunneling machine in the embodiment of the present invention.

[0074] Markings in the figure: 1 is a beam element, 2 is a circumferential bending spring element, 3 is a radial tangential spring element between rings, and 4 is a formation spring element. Detailed Embodiment

[0075] The present invention aims to provide a three-dimensional parametric simulation calculation method for the segment structure of a tunneling machine, which solves the problems of complex manual modeling, low efficiency and time-consuming calculation existing in the existing tunneling machine segment modeling and simulation scheme based on a simplified three-dimensional model. Its core idea is: introducing an integrated command set and a function module set into the automated modeling, so that researchers only need to set a small number of key parameters, and the system can quickly construct the segment structure model of the tunneling machine by calling various command sets and parameter systems, avoiding repetitive modeling work, thus improving the modeling efficiency; when it is necessary to modify the segment structure, only relevant parameters need to be adjusted to realize batch update of the model, which also improves the model modification efficiency; in addition, during the simulation process, the present invention optimizes the solution process, reduces the number of iterations in the non-linear analysis, improves the simulation calculation speed, realizes fast simulation, saves computing resources and time, and meets the requirements of scheme adjustment.

[0076] For easy understanding, first, the 3D segment calculation model of the tunneling machine based on the simplified 3D model is described. The 3D segments of the tunneling machine are used as the modeling object, and its specific structural components include: segment crown block, segment adjacent block, segment standard block, segment circumferential bolt, segment inter-ring bolt, grouting hole, lifting hole, inter-ring gasket, and caulking. The 3D segment calculation model is simplified on this basis. See Figure 2 , the segment crown block, segment adjacent block, and segment standard block are simulated using beam element 1, the segment circumferential bolt is simulated using circumferential flexural spring element 2, the segment inter-ring bolt is simulated using inter-ring radial and tangential spring element 3, and the interaction between the segment and the soil is simulated using stratum spring element 4.

[0077] Among them, beam element 1 uses BEAM3 element, which is mainly used to simulate the flexural stiffness of the segment. Usually, its cross-sectional characteristics are defined by real constants and may be equipped with different cross-sectional parameters to meet the stress requirements under different working conditions; circumferential flexural spring element 2 uses COMBIN39 element, which is connected to the segment beam element and is used to simulate the flexural stiffness of the circumferential bolt. This element can accurately reflect the mechanical properties of the circumferential joint and plays an important role in ensuring the stability of the overall structure; inter-ring radial and tangential spring element 3 uses COMBIN39 element, which is used to simulate the radial shear stiffness and tangential shear stiffness of the inter-ring bolt and is crucial for ensuring the connection performance between segment rings; stratum spring element 4 uses COMBIN39 element, which is used to simulate the support effect of the stratum on the segments of the tunneling machine. The stiffness parameters of the stratum spring are determined according to the geological conditions and can effectively simulate the interaction relationship between the stratum and the segments.

[0078] The flow of the 3D parametric simulation calculation method for the segment structure of the tunneling machine provided by the present invention is shown in Figure 1 , and it realizes rapid and accurate parametric modeling and simulation analysis of the segment structure of the tunneling machine by sequentially performing the following steps:

[0079] S1. Call the model initialization command set to initialize the modeling environment, and call the basic parameter command set to establish a basic parameter system including material property parameters, geometric feature parameters, and stratum characteristic parameters.

[0080] In this step, the initialization process includes: clearing historical data and defining the current simulation file and title, obtaining the current project data, initializing the simulation environment, setting the international unit system, and converting it to the cylindrical coordinate system.

[0081] Calling the basic parameter command set to establish a basic parameter system including material property parameters, geometric feature parameters, and stratum characteristic parameters includes:

[0082] (1) Call the material parameter definition function command set to define parameters such as the elastic modulus, density, and Poisson's ratio of the segment.

[0083] (2) Call the geometric feature parameter definition command set to define parameters such as the outer diameter of the segment, the ring width, the wall thickness, the number of segment blocks, the total number of bolts between rings, the offset angle of the closure block, the inner size of the closure block within the ring, the inner size of the adjacent block within the ring, the radial and tangential stiffness of the bolts between rings, and the bending stiffness of the circumferential bolts.

[0084] (3) Call the formation feature parameter definition command set to define parameters such as the embedment depth of the segment, the depth of the groundwater level, the ground surcharge, the unit weight of the surrounding rock, the surrounding rock grade, and the recommended values of the geotechnical design parameters.

[0085] S2. Call the load analysis command set to calculate and process the formation pressure on the segment to obtain the loads on the segment.

[0086] In this step, by obtaining the input geometric feature parameters and formation feature parameters, call the load calculation command set to calculate the vertical soil pressure, lateral soil pressure, lateral water pressure, and formation resistance load; by obtaining the global coordinate positioning data, call the global coordinate transformation command set to transform the local load components from the local coordinate system to the global coordinate system to obtain the global load component values, so that the load distribution conforms to the actual stress conditions of the segment.

[0087] S3. Call the structural modeling command set to construct a three-dimensional segment calculation model of the tunneling machine that includes nodes, beam elements, and spring elements.

[0088] In this step, the specific implementation process of constructing the three-dimensional segment calculation model of the tunneling machine is as follows:

[0089] (1) Obtain the input segment geometric structure parameters, call the node generation command set, and automatically generate node coordinates and establish nodes.

[0090] (2) Obtain the input material parameters, call the beam element generation command set, and assign the corresponding parameters to the element attributes to establish beam elements for simulating the segment structure.

[0091] (3) Call the segment circumferential and between-ring generation command set to create circumferential and between-ring spring elements connected to the beam elements, and simulate the tangential and radial performance of the bolts between rings with between-ring radial spring elements and between-ring tangential spring elements, and simulate the circumferential bending performance of the circumferential bolts with circumferential bending spring elements.

[0092] (4) Obtain the input soil layer parameters, call the foundation spring generation command set to generate foundation springs connected to the beam element nodes for simulating the interaction between the segment and the soil layer.

[0093] (5) Obtain the calculated global load component values, call the load application command set, and thus apply the loads to the beam element nodes.

[0094] (6) Invoke the constraint addition command set to simulate the constraint effect of the formation on the segment of the tunneling machine by constraining the horizontal and vertical displacements of the formation spring nodes, and ensure that the top nodes of the segment are only affected by the vertical soil pressure by constraining the vertical displacement of the highest node of the beam element, so as to accurately simulate the load distribution of the ground surface on the top of the segment.

[0095] S4. Invoke the calculation and analysis command set to perform automatic simulation solution processing on the three-dimensional segment calculation model of the tunneling machine, and automatically output the calculation results.

[0096] In this step, the specific implementation process of the automatic simulation solution processing is as follows:

[0097] (1) Enter the solution module and set the type of simulation solution through static analysis for static analysis.

[0098] (2) Through the load step and sub-step settings, control and process the nonlinear analysis, specifically including: defining the number of sub-steps in the load step, controlling the load application rate; setting the time step increment to ensure the stability of the calculation process; adjusting the load increment size to optimize the iterative calculation efficiency.

[0099] (3) Invoke the criterion command set to set the convergence criterion and start the iterative calculation; among them, the setting of the convergence criterion includes: setting the convergence criteria for force, displacement, moment and rotation angle; defining the allowable error range to ensure the calculation accuracy; adjusting the convergence parameters to ensure the reliability of the calculation results; during the iterative process, optimize the iterative strategy: improve the stability of the solution by activating the linear search function; handle complex nonlinear problems by increasing the maximum number of equilibrium iterations; achieve adaptive control of the calculation process by adjusting the number of load sub-steps.

[0100] (4) Obtain the calculation results of the beam element nodes and extract and process the displacement and internal force data.

[0101] (5) Invoke the post-processing visualization command set to obtain the displacement and internal force data, and automatically output the internal force nephograms of the segment structure moment, shear force, axial force and deformation structure.

[0102] S5. Obtain the calculation results, invoke the reinforcement analysis module and the structural calculation report module, and automatically obtain the recommended segment reinforcement information of the tunneling machine and the structural calculation report.

[0103] In this step, by obtaining the generated displacement and internal force data, invoke the reinforced concrete reinforcement module to automatically analyze the data to obtain the segment reinforcement data of the tunneling machine; by obtaining the model parameters, model displacement and internal force data, nephogram and reinforcement data, invoke the structural calculation report generation module to obtain the structural calculation report.

[0104] Taking the parametric modeling and simulation of the three-dimensional segment of a tunneling machine based on the ANSYS platform as an example, in this embodiment, the APDL command flow (ANSYS Parametric Design Language) is adopted. First, the material properties, geometric dimensions, and load parameters are set through parametric definition. Then, based on these parameters, nodes and elements are automatically generated, and the loads acting on the segment are automatically calculated and applied based on these parameters, that is, the rapid parametric modeling of the tunneling machine segment can be realized. Finally, by setting the iterative calculation control parameters and post-processing commands, the solution of the structural response and the result display are completed.

[0105] Since this embodiment defines the model in a parametric way and calls a command set with fixed functions for modeling and simulation, there is no need to repeat the modeling operation, so the analysis efficiency is significantly improved. Secondly, when the segment parameters need to be modified, only the corresponding input parameters need to be adjusted to quickly complete the new analysis and improve the design optimization efficiency.

[0106] See Figure 3 , the implementation process of the three-dimensional parametric simulation calculation of the tunneling machine segment structure in this embodiment is as follows:

[0107] I. Initialization settings:

[0108] Use the / clear command to clear all historical data in the current database to avoid interference from historical data on this modeling. And use the / filename command to define the name of the current simulation file, use the / title command to set the analysis title, use the / units,si command to specify the use of the International System of Units (SI), and finally use the csys,1 command to specify the use of the cylindrical coordinate system.

[0109] II. Call the basic parameter command set to establish a basic parameter system:

[0110] Segment material property setting: Use commands to define the geometric parameter group, material parameter group, and load parameter group to establish a basic parameter system. Set the basic characteristic parameters of the segment material, such as elastic modulus, density, and Poisson's ratio, etc. Specifically, use the mp command to specify these material parameters for the segment structure.

[0111] Define the segment geometric characteristic parameters and formation characteristic parameters: Define the segment geometric characteristic parameters, including outer diameter, ring width, wall thickness, etc.; at the same time, set the formation characteristic parameters, including overburden thickness, groundwater depth, rock mass unit weight, and other parameters. These parameters will be stored in the corresponding parameter arrays for subsequent calculation and analysis.

[0112] III. Calculation of the loads acting on the segment:

[0113] Calculate the vertical earth pressure acting on the segment according to the following formula:

[0114] ;

[0115] Calculate the lateral earth pressure on the segment according to the following formula:

[0116] ;

[0117] ;

[0118] Calculate the lateral water pressure on the segment according to the following formula:

[0119] ;

[0120] ;

[0121] Calculate the vertical buoyancy force on the segment according to the following formula:

[0122] ;

[0123] Calculate the formation resistance on the segment according to the following formula:

[0124] ;

[0125] Where: is the vertical earth pressure; is the lateral earth pressure at the crown of the segment; is the lateral earth pressure at the bottom of the segment; is the lateral water pressure at the crown of the segment; is the lateral water pressure at the bottom of the segment; is the buoyancy force; is the formation resistance; is the embedment depth of the segment; is the depth of the groundwater level; is the ground surface surcharge; is the outer diameter of the segment; is the submerged unit weight; is the natural unit weight; is the unit weight of water; is the lateral pressure coefficient.

[0126] IV. Node and element creation:

[0127] According to the geometric characteristic parameters, call the node generation command set to automatically calculate the node coordinates, and create nodes through the n command. And according to the material properties and geometric characteristic parameters, call the element generation command set, and create elements in the following way:

[0128] Use the et,1,beam3 command to create beam elements.

[0129] Create the circumferential bending spring element using the et,2,combin39 command.

[0130] Create the formation spring element using the et,3,combin39 command.

[0131] Create the inter-ring radial spring element using the et,4,combin39 command.

[0132] Create the inter-ring tangential spring element using the et,5,combin39 command.

[0133] V. Load Application:

[0134] First, obtain the load calculation results and convert the loads in the cylindrical coordinate system to components in the global coordinate system:

[0135] Vertical load calculation formula:

[0136] ;

[0137] Where, is the vertical load of the i th node in the k th ring, is the bottom pressure of the k th ring, and are the vertical distances between adjacent nodes.

[0138] Horizontal load calculation formula:

[0139] ;

[0140] Where, is the horizontal load of the i th node in the k th ring, is the horizontal pressure of the k th ring, and are the horizontal distances between adjacent nodes.

[0141] Then, call the load application command set. The f command is mainly used in the command set to apply the above calculated load components to the corresponding nodes of the beam element.

[0142] VI. Boundary Conditions and Constraint Settings:

[0143] Call the constraint addition command set. The d command is mainly used in the command set to implement the displacement constraint on the nodes of the formation spring tube, and to implement the vertical displacement of the highest point node of the beam element, so as to simulate the constraint conditions of the tunnel of the shield segment in the actual project. Through the above steps, the three-dimensional calculation model of the shield segment structure has been obtained.

[0144] VII. Automatic simulation solution settings for the three-dimensional calculation model:

[0145] Enter the solution stage, use the / solu command to enter the solver, and set ANTYPE, STATIC for static analysis.

[0146] VIII. Solving iteration calculation control and executing the solution:

[0147] The implementation of the iterative calculation steps includes:

[0148] 1. Achieve the control of nonlinear analysis through load step and sub-step settings. The specific implementation method is as follows:

[0149] (1) Use the / NSUBST command to define the number of sub-steps in the load step and control the load application rate.

[0150] (2) Use the TIME command to set the time step increment to ensure the stability of the calculation process.

[0151] (3) Adjust the load increment size through the ACEL command to optimize the iterative calculation efficiency.

[0152] 2. Establish a convergence criterion control system. The specific implementation method is as follows:

[0153] (1) Use the SOLVE command combined with the OUTRES command to set the convergence criteria for force, displacement, moment, and rotation angle.

[0154] (2) Use the TOLER command to define the allowable error range to ensure the calculation accuracy.

[0155] (3) Activate the nonlinear geometric option by adjusting the parameters in the SOLVE command, such as NLGEOM, ON, to ensure the reliability of the calculation results.

[0156] 3. Optimize the iterative strategy. The specific implementation method is as follows:

[0157] (1) Activate the linear search function in the / SOLU module to improve the stability of the solution.

[0158] (2) Increase the maximum equilibrium iteration times and handle complex nonlinear problems by adjusting the ITER parameter in the / SOLU module.

[0159] (3) Adjust the number of load sub-steps and achieve the adaptive control of the calculation process through the SUBST parameter in the / SOLU module.

[0160] 4. By calling the solution calculation command set, mainly use the solve command to execute the iterative calculation and solution until the convergence is completed.

[0161] IX. Output the analysis results:

[0162] 1. Calculation result extraction and visualization, the specific implementation method is as follows:

[0163] (1) After calling to enter the post-processing and internal force extraction command set, the main command of the command set is / POST1. Enter the post-processing module, select specific elements and nodes, and use the main commands ETABLE and PLNSOL to extract key calculation data such as the bending moment, shear force, axial force, and deformation of the segment.

[0164] (2) Call the visualization command set, the main command of the command set is the Eplot command, and perform automatic generation processing on the internal force contour map of the structure. Use the Eplot command to generate visualization results such as the internal force contour map and the deformation contour map.

[0165] 2. Data sorting and output, the specific implementation method is as follows:

[0166] (1) Call the data integration command set, and the main commands of the command set adopt and commands to establish a calculation data table and store the generated calculation data such as displacements and internal forces.

[0167] (2) Call the data processing command set, and the main command of the command set adopts command to extract the maximum bending moment, shear force, axial force, and displacement data of the segment for subsequent analysis.

[0168] (3) Call the reinforced concrete reinforcement module, import the maximum bending moment, shear force, axial force, and displacement data into the module, automatically analyze the data, and obtain the segment reinforcement data of the tunneling machine.

[0169] (4) Obtain the model parameters, segment displacement and internal force data, contour maps, and reinforcement data, and call the structure calculation report generation module. The main commands of the module adopt and to obtain the structure calculation report.

[0170] Based on the above embodiments, by calling various command sets and parameter systems, the segment structure model of the tunneling machine can be quickly constructed. As can be seen from Figure 3 , in the whole process, except for the need to manually input some key parameters, the rest are automatically processed by the system, avoiding repetitive modeling work, thus improving the modeling efficiency; secondly, when the segment structure needs to be modified, only the relevant parameters need to be adjusted to achieve batch update of the model, improving the model modification efficiency.

[0171] Finally, it should be noted that the above embodiments are only preferred embodiments and are not intended to limit the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the spirit of the present invention and the scope protected by the claims, several modifications, equivalent substitutions, improvements, etc. should all be included within the protection scope of the present invention.

Claims

1. A three-dimensional parametric simulation calculation method for a tunnel boring machine segment structure, characterized in that: The following steps are involved: S1. Calling the model initialization command set to initialize the modeling environment, and calling the basic parameter command set to establish a basic parameter system including material attribute parameters, geometric feature parameters and formation characteristic parameters; S2. Calling a load analysis command set to calculate the formation pressure on the segment and obtain the load on the segment; S3. Calling the structural modeling command set to construct a three-dimensional segment calculation model of the tunnel boring machine including nodes, beam units and spring units; S4. Calling the calculation and analysis command set to automatically simulate and solve the three-dimensional segment calculation model of the tunnel boring machine, and automatically output the calculation results; S5. Obtain the calculation results, call the reinforcement analysis module and the structural calculation report module, and automatically obtain the recommended tunnel boring machine segment reinforcement information and structural calculation report; In step S3, the calling of the structural modeling command set to construct a three-dimensional segment calculation model of the roadheader including nodes, beam units and spring units includes: Obtain the input segment geometry parameters, call the node generation command set to automatically generate node coordinates and establish nodes; Obtain the input material parameters, call the beam unit generation command set, and assign corresponding parameters to the unit properties to establish the beam unit for simulating the segment structure; Call the segment annular and inter-annular generation command set to create annular and inter-annular spring units connected to the beam unit, use the inter-annular radial spring unit and the inter-annular tangential spring unit to simulate the tangential and radial performance of the inter-annular bolts, and use the annular bending spring unit to simulate the annular bending performance of the annular bolts; Obtain the input soil layer parameters, call the command set for generating foundation springs, and generate foundation springs connected to the beam unit nodes for simulating the interaction between the pipe segment and the soil layer; Obtain the calculated global load component values, call the load application command set, and apply the load to the beam element nodes; Call the constraint addition command set to simulate the constraint effect of the stratum on the tunnel boring machine segment by constraining the horizontal and vertical displacements of the stratum spring nodes. By constraining the vertical displacement of the highest node of the beam unit, ensure that the top node of the segment is only affected by the vertical earth pressure.

2. A three-dimensional parametric simulation calculation method for a tunnel boring machine segment structure according to claim 1, characterized in that: In step S1, the calling of the model initialization command set to initialize the modeling environment includes: Clear historical data and define the current simulation file and title, initialize the simulation environment, set the international unit system and convert to the cylindrical coordinate system.

3. A three-dimensional parametric simulation calculation method for a tunnel boring machine segment structure according to claim 1, characterized in that: In step S1, the calling of the basic parameter command set to establish a basic parameter system including material property parameters, geometric characteristic parameters and formation characteristic parameters includes: Call the material parameter definition function command set to define the segment elastic modulus, density and Poisson's ratio parameters; Call the geometric feature parameter definition command set to define the segment outer diameter, ring width, wall thickness, number of segment blocks, total number of inter-ring bolts, capping block offset angle, capping block inner ring size, adjacent block inner ring size, inter-ring bolt radial and tangential stiffness, and annular bolt bending stiffness parameters; The formation characteristic parameter definition command set is called to define the segment burial depth, groundwater level depth, ground overload, surrounding rock weight, surrounding rock grade and recommended values ​​of geotechnical design parameters.

4. A three-dimensional parametric simulation calculation method for a tunnel boring machine segment structure according to claim 1, characterized in that: In step S2, the calling of the load analysis command set to calculate the formation pressure on the segment to obtain the load on the segment includes: Obtain the input geometric characteristic parameters and formation characteristic parameters, call the load calculation command set, and calculate the vertical earth pressure, lateral earth pressure, lateral water pressure and formation resistance load; Obtain global coordinate positioning data, call the global coordinate conversion command set, transform local load components from the local coordinate system to the global coordinate system, obtain global load component values, and make the load distribution conform to the actual stress conditions of the segment.

5. A three-dimensional parametric simulation calculation method for a tunnel boring machine segment structure according to claim 1, characterized in that: In step S4, the calling of the calculation and analysis command set automatically simulates and solves the three-dimensional segment calculation model of the tunnel boring machine and automatically outputs the calculation results, including: Enter the solution module and set the simulation solution type through static analysis to perform static analysis; Control the nonlinear analysis through load step and sub-step settings; Call the criterion command set to set the convergence criterion and start iterative calculation; Obtain the calculation results of the beam unit nodes and extract and process the displacement and internal force data; Call the post-processing visualization command set to obtain displacement and internal force data, and automatically output the internal force cloud diagram including the bending moment, shear force, axial force of the segment structure and the deformed structure.

6. A three-dimensional parametric simulation calculation method for a tunnel boring machine segment structure according to claim 5, characterized in that: The control processing of nonlinear analysis through load step and sub-step setting includes: Define the number of substeps in a load step to control the load application rate; set the time step increment to ensure the stability of the calculation process; adjust the load increment size to optimize the iterative calculation efficiency.

7. A three-dimensional parametric simulation calculation method for a tunnel boring machine segment structure according to claim 5, characterized in that: The process of setting the convergence criterion includes: Set convergence criteria for forces, displacements, moments, and rotations; define tolerances; and adjust convergence parameters.

8. A three-dimensional parametric simulation calculation method for a tunnel boring machine segment structure according to claim 5, characterized in that: The iterative calculation includes: optimizing the iteration strategy during the iteration process; the optimization of the iteration strategy includes: improving the stability of the solution by activating the linear search function; dealing with nonlinear problems by increasing the maximum number of equilibrium iterations; and achieving adaptive control of the calculation process by adjusting the number of load sub-steps.

9. A three-dimensional parametric simulation calculation method for a tunnel boring machine segment structure according to claim 1, characterized in that: In step S5, the calculation results are obtained, and the reinforcement analysis module and the structure calculation report module are called to automatically obtain the recommended tunnel boring machine segment reinforcement information and the structure calculation report, including: Obtain the generated displacement and internal force data, call the reinforced concrete reinforcement module to automatically analyze the data, and obtain the tunnel boring machine segment reinforcement data; Obtain model parameters, model displacement and internal force data, cloud map and reinforcement data, call the structural calculation report generation module, and obtain the structural calculation report.

Images