Method and device for generating tunnel lining structure

Abstract

The invention discloses a tunnel lining structure generation method and device, and relates to the technical field of tunnel engineering.The method comprises the steps that geometric parameters of a four-center circle section are obtained through a data interface; a multi-element polar coordinate system is constructed based on the geometric parameters of the four-center circle section, coordinate calculation is carried out based on the multi-element polar coordinate system, and a structure node coordinate set and a constraint node coordinate set are generated; constructing a finite element model based on the structure node coordinate set and the constraint node coordinate set, and performing internal force analysis on the finite element model to obtain an internal force analysis result; and based on an internal force analysis result, through discretized reinforcement ratio analysis and safety coefficient evaluation, outputting a target reinforcement scheme, and based on the target reinforcement scheme, generating a tunnel lining structure. Model generation is directly driven through parameterized input, the accuracy of load application is improved, and the safety of the tunnel lining structure is guaranteed.

Description

Technical Field

[0001] This application relates to the field of tunnel engineering technology, and in particular to a method and apparatus for generating tunnel lining structures. Background Technology

[0002] In tunnel engineering structural design, the tunnel lining structure is a permanent support structure built along the perimeter of the tunnel body to ensure the long-term safe operation of the tunnel. In tunnel engineering structural design, the effect of the surrounding rock on the lining is usually analyzed as an equivalent external load.

[0003] Currently, in the design and construction of tunnel lining structures, the analysis results based on finite element software directly affect the amount of reinforcement and structural safety of the lining. However, in practical applications, it has been found that because the load application range and location of the lining structure are highly dependent on manual judgment and selection based on drawings, it is difficult to accurately correspond to the actual contour of the lining. This results in significant deviations in load application, leading to potential safety hazards in the lining under actual loads.

[0004] Therefore, improving the accuracy of load application has become a key issue that urgently needs to be addressed. Summary of the Invention

[0005] The main objective of this application is to provide a method and apparatus for generating tunnel lining structures, aiming to solve the technical problem of how to improve the accuracy of load application.

[0006] To achieve the above objectives, this application proposes a method for generating a tunnel lining structure, the method comprising: Obtain the geometric parameters of the four-centered circular cross-section through the data interface; A multivariate polar coordinate system is constructed based on the geometric parameters of the four-centered circular cross section, and coordinate calculations are performed based on the multivariate polar coordinate system to generate a set of structural node coordinates and a set of constraint node coordinates. A finite element model is constructed based on the set of structural node coordinates and the set of constraint node coordinates, and internal force analysis is performed on the finite element model to obtain the internal force analysis results. Based on the internal force analysis results, a target reinforcement scheme is output through discretized reinforcement ratio analysis and safety factor assessment, and a tunnel lining structure is generated based on the target reinforcement scheme.

[0007] In one embodiment, the step of constructing a multivariate polar coordinate system based on the geometric parameters of the four-centered circular cross-section, and performing coordinate calculations based on the multivariate polar coordinate system to generate a set of structural node coordinates and a set of constraint node coordinates includes: Establish a global rectangular coordinate system with the center of the arched arc as the origin; Based on the geometric parameters of the four-centered circular cross section, the topological relationship and geometric logic of each arc segment are analyzed, the coordinates of the center of each remaining arc segment in the global rectangular coordinate system are calculated in turn, and the corresponding local polar coordinate system is established. The tunnel profile is discretized based on the principle of equal arc length, and the polar angle of each discrete point is determined. By combining the local polar coordinate system with the polar angle of each discrete point, the rectangular coordinates of each structural node are calculated, and a set of structural node coordinates is generated. The coordinates of the constraint nodes are calculated based on the set of coordinates of the structural nodes, and a set of coordinates of the constraint nodes is generated.

[0008] In one embodiment, the step of discretizing the tunnel profile based on the principle of equal arc length and determining the polar angle of each discrete point includes: Obtain the total arc length of the tunnel profile and the predetermined number of discrete elements; The standard arc length of each element is calculated based on the total arc length of the tunnel profile and the predetermined number of discrete elements. For each arc segment, based on the radius of each arc segment and the standard arc length, the polar angle increment of each discrete point on each arc segment relative to the origin of the local polar coordinate system is calculated, and the polar angle of each discrete point is obtained.

[0009] In one embodiment, the step of calculating the constraint node coordinates based on the structure node coordinate set and generating the constraint node coordinate set includes: Based on the set of structural node coordinates, calculate the local tangent vector at each structural node; The local tangent vector is rotated and then normalized to obtain the unit outward normal vector. Based on the unit outward normal vector, the coordinates of the constraint nodes corresponding to each structural node are calculated according to the preset offset distance, and a set of constraint node coordinates is generated.

[0010] In one embodiment, the step of constructing a finite element model based on the set of structural node coordinates and the set of constraint node coordinates, and performing internal force analysis on the finite element model to obtain the internal force analysis results includes: Based on the set of structural node coordinates and the set of constraint node coordinates, a finite element model is generated through ordered pair encapsulation and sequential modeling strategies. The finite element model includes structural elements and constraint spring elements. Based on the predefined load conditions and the node coordinates in the finite element model, the load case is defined, and the defined load case is applied to the finite element model to obtain the processed finite element model. The internal force analysis was performed on the processed finite element model to obtain the internal force analysis results.

[0011] In one embodiment, the step of generating a finite element model based on the set of structural node coordinates and the set of constraint node coordinates, through an ordered pair encapsulation and sequential modeling strategy, wherein the finite element model includes structural elements and constraint spring elements, includes: Based on the set of structural node coordinates and the set of constraint node coordinates, each structural node and its corresponding constraint node are defined as a node pair; Each node pair is encapsulated with its corresponding spring constraint attribute to form multiple ordered number pair units; The ordered number pairs are sorted along the tunnel contour in a preset direction to form an ordered sequence; Read the ordered sequence and, based on the encapsulated spring constraint properties, create structural units and constraint spring units in batches according to the sequence order.

[0012] In one embodiment, the step of defining load cases based on predefined load conditions and node coordinates in the finite element model, and applying the defined load cases to the finite element model to obtain a processed finite element model, includes: The node coordinates in the finite element model are traversed, and the nodes are identified and grouped based on their coordinate positions to form different load application node sets. By calling the load application command of the finite element solver through the program interface, predefined load values ​​are applied in batches to the corresponding load application node set.

[0013] In one embodiment, the step of traversing the node coordinates in the finite element model, identifying and grouping them based on their coordinate positions to form different load application node sets includes: The node coordinates in the finite element model are traversed, and the ordinate of the node is compared with the ordinate of the rightmost node of the tunnel structure to filter out the set of nodes that bear the vertical load. Based on the direction of the node on the y-axis of the global Cartesian coordinate system, select the set of nodes that bear horizontal loads in different directions.

[0014] In one embodiment, the step of outputting a target reinforcement scheme based on the internal force analysis results through discretized reinforcement ratio analysis and safety factor assessment includes: Discretize the reinforcement ratio design range into multiple candidate reinforcement ratio levels; For each candidate reinforcement ratio level, the safety factor distribution of the structure is calculated based on the internal force analysis results, and the minimum safety factor is extracted from the safety factor distribution. The minimum safety factor is compared with a preset safety factor threshold to select candidate reinforcement ratio schemes, which meet the preset safety requirements. Using the minimum reinforcement ratio as the screening criterion, the candidate reinforcement ratio schemes are screened a second time to obtain the target reinforcement scheme.

[0015] Furthermore, to achieve the above objectives, this application also proposes a tunnel lining structure generating apparatus, the tunnel lining structure generating apparatus comprising: The parameter acquisition module is used to obtain the geometric parameters of the four-centered circular cross-section through the data interface. The coordinate generation module is used to construct a multivariate polar coordinate system based on the geometric parameters of the four-centered circular cross section, and to perform coordinate calculations based on the multivariate polar coordinate system to generate a set of structural node coordinates and a set of constraint node coordinates. The internal force analysis module is used to construct a finite element model based on the set of coordinates of the structural nodes and the set of coordinates of the constraint nodes, and to perform internal force analysis on the finite element model to obtain the internal force analysis results. The scheme output module is used to output a target reinforcement scheme based on the internal force analysis results, through discretized reinforcement ratio analysis and safety factor evaluation, and generate a tunnel lining structure based on the target reinforcement scheme.

[0016] One or more technical solutions proposed in this application have at least the following technical effects: The geometric parameters of the four-centered circular cross-section are obtained through a data interface. A multivariate polar coordinate system is constructed based on these parameters, and coordinate calculations are performed to generate sets of structural node coordinates and constraint node coordinates. Obtaining the geometric parameters of the four-centered circular cross-section through the data interface accurately describes the complex shape of the tunnel. Parametric input directly drives model generation, solving the problems of reliance on manual drawing processing and errors prone to occur in manual modeling. Systematic coordinate calculation and node generation eliminate model deviations introduced by human operation, ensuring the accuracy of mesh generation and load application, and fundamentally improving the reliability of internal force analysis results.

[0017] A finite element model is constructed based on the coordinate sets of structural nodes and constraint nodes, and internal force analysis is performed on the finite element model to obtain the internal force analysis results. Based on the internal force analysis results, a target reinforcement scheme is output through discretized reinforcement ratio analysis and safety factor evaluation, and a tunnel lining structure is generated based on the target reinforcement scheme. Based on discretized reinforcement ratio analysis and safety factor evaluation, the optimal reinforcement scheme that balances safety and economy can be quickly and objectively selected, overcoming the blindness of repeated trial calculations in traditional empirical design and achieving scientific optimization of the reinforcement scheme. Furthermore, the parametric basis provides strong versatility, allowing for rapid adaptation to different cross-sectional dimensions and load conditions. Simultaneously, standardized data output provides a complete basis for design verification and iteration, powerfully promoting the modernization transformation of tunnel lining design from experience-based to data-driven. Through discretized reinforcement ratio analysis and safety factor evaluation, the reinforcement design is localized and safety indicators are quantified, solving the drawbacks of conservative or insufficient overall reinforcement, achieving optimized output of economical and safe reinforcement schemes, improving the accuracy of load application, and ensuring the safety of the tunnel lining structure. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the first embodiment of the method for generating tunnel lining structures according to this application; Figure 2 This is a cross-sectional view of the tunnel with four centers according to an embodiment of this application; Figure 3 This is a schematic diagram of the nodal polar angle calculation in an embodiment of this application; Figure 4 This is a schematic diagram of polar coordinate transformation based on piecewise circular arc parameterization according to an embodiment of this application; Figure 5 This is a schematic diagram of vector-based node self-offset in an embodiment of this application; Figure 6 This is a schematic diagram showing the structural and constraint spring sequence modeling of an embodiment of this application; Figure 7 This is a schematic diagram of the calculation of the tunnel lining structure according to an embodiment of this application; Figure 8 This is a schematic diagram of the tunnel cross-section structure according to an embodiment of this application; Figure 9 This is a bar chart showing the safety factor of an embodiment of this application; Figure 10 This is a safety factor diagram of the optimal solution in the embodiments of this application; Figure 11 This is a schematic diagram of the modular structure of the tunnel lining structure generation device of this application.

[0021] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0023] This application provides a method for generating a tunnel lining structure, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the method for generating tunnel lining structures according to this application.

[0024] In this embodiment, the method for generating the tunnel lining structure includes steps S10 to S40: Step S10: Obtain the geometric parameters of the four-centered circular cross-section through the data interface.

[0025] It should be noted that in tunnel engineering, the four-centered circular cross-section is a contour structure, composed of four smoothly connected circular arc segments, possessing good structural stress characteristics and ease of construction. For example, the four-centered circular cross-section is a tunnel lining cross-sectional shape, composed of four circular arc segments, each with an independent center. The geometric parameters of the four-centered circular cross-section can include the coordinates of each center, radius, and information such as the connection points of the arc segments, used to define the specific dimensions and shape of the cross-section.

[0026] For example, a graphical user interface can be built using PySimpleGUI to receive the geometric parameters of the four-center circular cross-section input by the user; the parameters input by the user interface can be obtained through values, and a hierarchical structured parameter dictionary can be built, in which the geometric parameters and discretized parameters of each arc segment are classified and stored separately. This can realize the data interface conversion from graphical interface to structured data, and provide an accurate input parameter foundation for the subsequent construction of multivariate polar coordinate system.

[0027] Step S20: Construct a multivariate polar coordinate system based on the geometric parameters of the four-centered circular cross section, and perform coordinate calculations based on the multivariate polar coordinate system to generate a set of structural node coordinates and a set of constraint node coordinates.

[0028] It should be noted that a multivariate polar coordinate system can be constructed based on multiple poles, allowing complex curves to be described using radii and angles, thus simplifying coordinate calculations. In a multivariate polar coordinate system, the coordinate values ​​of each point on the cross-section are calculated through geometric relationships. The structural node coordinate set represents the coordinate dataset of discrete points in the finite element model, used to define mesh nodes. The constraint node coordinate set specifies the node coordinate dataset of boundary conditions or constraints, used to simulate support or fixing conditions.

[0029] For example, a MAPDL (Mechanical Application Parametric Design Language) instance can be launched using the `launch_mapdl()` function of `ansys.mapdl.core`, and then nodes can be generated using MAPDL commands in a multivariate polar coordinate system. `ansys.mapdl.core` is used to implement bidirectional communication and data exchange between Python and ANSYS, and the `launch_mapdl()` function returns an instance of the MAPDL class for subsequent ANSYS operations. The MAPDL instance is an independent ANSYS Mechanical APDL calculation process launched via the `launch_mapdl()` function.

[0030] Step S30: Construct a finite element model based on the set of structural node coordinates and the set of constraint node coordinates, and perform internal force analysis on the finite element model to obtain the internal force analysis results.

[0031] It should be noted that the finite element model is a numerical analysis model that discretizes the structure into small elements, such as beams or shells. A finite element model can be constructed based on a set of nodal coordinates to simulate mechanical behavior. Internal force analysis can be understood as calculating the internal forces of the model under load, such as bending moments and axial forces, using the finite element method to evaluate the structural response. The results of internal force analysis are the force or stress distribution data obtained after the analysis, used for subsequent design evaluation.

[0032] Step S40: Based on the internal force analysis results, the target reinforcement scheme is output through discretized reinforcement ratio analysis and safety factor assessment, and the tunnel lining structure is generated based on the target reinforcement scheme.

[0033] For example, the lining cross-section can be discretized into multiple segments, and the reinforcement ratio (such as the ratio of steel reinforcement area to concrete area) of each segment can be calculated to achieve local optimization. The safety factor for each section can be calculated by comparing the internal force analysis results with material strength, ensuring structural reliability. The target reinforcement scheme is the final steel reinforcement configuration scheme based on the analysis and evaluation output, used to guide the tunnel lining construction design.

[0034] In this embodiment, the geometric parameters of the four-centered circular cross-section are obtained through a data interface, enabling precise description of the complex shape of the tunnel. Parametric input directly drives model generation, solving the error-prone problems of traditional methods relying on manual drawing processing and manual modeling. Systematic coordinate calculation and node generation eliminate model deviations introduced by human operation, ensuring the accuracy of mesh generation and load application, and fundamentally improving the reliability of internal force analysis results. Based on discretized reinforcement ratio analysis and safety factor assessment, the optimal reinforcement scheme that balances safety and economy can be quickly and objectively selected, overcoming the blindness of repeated trial calculations in traditional empirical design and achieving scientific optimization of reinforcement schemes. Furthermore, the parametric foundation provides strong versatility, quickly adapting to different cross-sectional dimensions and load conditions. Simultaneously, standardized data output provides a complete basis for the verification and iteration of the tunnel lining model, powerfully promoting the modernization of tunnel lining from experience-based to data-driven. Through discretized reinforcement ratio analysis and safety factor assessment, the localization of reinforcement design and the quantification of safety indicators improve the accuracy of load application and ensure the safety of the tunnel lining structure.

[0035] In the second embodiment, step S20 includes: Step S201: Establish a global rectangular coordinate system with the center of the arch arc as the origin.

[0036] It should be noted that the global rectangular coordinate system, which is a plane rectangular coordinate system established with the center of the arch arc as the origin, can serve as a unified reference datum for the entire cross-sectional geometry definition.

[0037] Step S202: Based on the geometric parameters of the four-centered circular cross section, analyze the topological relationship and geometric logic of each arc segment, calculate the coordinates of the center of each remaining arc segment in the global rectangular coordinate system, and establish the corresponding local polar coordinate system.

[0038] It should be noted that topological relationships and geometric logic refer to the structural logic such as the connection order and tangency relationship between the arc segments in the four-centered circular cross-section. The local polar coordinate system can be understood as a polar coordinate system established with the center of each arc segment as its pole, used to conveniently describe the points on the arc.

[0039] An example is a schematic diagram of a four-centered circular cross-section of a tunnel. Figure 2 As shown, the geometric parameters of the four-centered circular cross-section include: the radius of the arch arc. , radius of the side wall arc Corner radius , radius of the inverted arch Central angle of the vault Central corner of the side wall and the central angle Using the center of the arc corresponding to the vaulted arch as the origin of the global rectangular coordinate system, the start and end coordinates of the remaining arcs and the precise positions of their corresponding centers are calculated. A local coordinate system is then established using the center points of the remaining arcs. Since some points overlap when calculating the start and end points of the arcs, a total of [number missing] calculations are required. Figure 2 The coordinates of the five key points and the four center points are shown in the following formula:

[0040]

[0041]

[0042]

[0043] The coordinates of the aforementioned nodes are used to subsequently form the coordinate equations corresponding to the arcs. It should be noted that in the finite element analysis of tunnel lining structures, the continuous overall structure needs to be discretized into a finite number of n elements to construct a computational model suitable for numerical simulation. During the discretization process, the element size and number are key parameters affecting the accuracy of the calculation results. Overly coarse element meshing may lead to excessive model stiffness, thus overestimating the structural response; while overly fine meshing significantly increases computational resource requirements and affects analysis efficiency. Therefore, reasonable mesh density control is necessary to balance computational accuracy with computational efficiency. Considering the typical size of tunnels, this embodiment discretizes the structure into 100 elements.

[0044] Step S203: Discretize the tunnel profile based on the principle of equal arc length and determine the polar angle of each discrete point.

[0045] It should be noted that the equal arc length principle refers to dividing the entire tunnel outline into several segments, each with an equal arc length. Step S203 includes: obtaining the total arc length of the tunnel outline and the predetermined number of discrete elements; calculating the standard arc length of each element based on the total arc length of the tunnel outline and the predetermined number of discrete elements; for each arc segment, calculating the polar angle increment of each discrete point on each arc segment relative to the origin of the local polar coordinate system based on the radius and standard arc length of each arc segment, thus obtaining the polar angle of each discrete point.

[0046] The total arc length refers to the total length of the entire four-centered circular cross-sectional profile. The number of discrete elements is a pre-defined number of segments into which the profile is divided. The standard arc length is the target arc length of each segment, calculated by dividing the total arc length by the number of discrete elements. The polar angle increment refers to the central angle between the lines connecting two adjacent discrete points to the center of the circle in the local polar coordinate system, which is calculated based on the radius of the arc and the standard arc length.

[0047] For example, the entire circular arc geometry model can be divided into several arc segments of equal length, with each arc segment corresponding to one element, thus ensuring that the spacing between all adjacent nodes on the arc is exactly the same, and the arc length... for A schematic diagram for calculating the polar angle is shown below. Figure 3 As shown. Figure 3 middle, Indicates the polar angle corresponding to the previous node. Indicates the starting point of the arc. Indicates the endpoint of the arc. This indicates the starting point of the arc. Depending on the arc range within which the element is located, the polar angle calculation formula for each element is as follows:

[0048]

[0049] in, This indicates the radius of the arc containing the element. This indicates the polar angle corresponding to the previous unit. In particular, if it is the starting node on a certain arc, This represents the initial azimuth angle corresponding to the arc, where the initial azimuth angle on each arc segment is:

[0050] Where P represents the starting node of the arc, and O represents the center of the corresponding arc. Based on the segmented arc parameterization, the right side of the graph is divided into three segments according to the different centers and radii of the arcs. Assuming there are three points I, J, and K located on the three arc segments respectively, the range and polar coordinates of the points are determined according to the center and radius of the arc they belong to. The transformed point positions are as follows: Figure 4 As shown.

[0051] Step S204: Combine the local polar coordinate system with the polar angle of each discrete point to calculate the rectangular coordinates of each structural node and generate a set of structural node coordinates.

[0052] For example, by combining the local polar coordinate system with the polar angle of each discrete point, the polar coordinate representation of the node corresponding to each element can be uniquely determined. Considering that there may be overlapping nodes between different elements, this embodiment uniformly uses the coordinates of the starting node of the element as the calculation node. ,in The corresponding polar coordinates are To convert it to a rectangular coordinate system, we can use the mapping relationship between polar coordinates and rectangular coordinates. The specific conversion formula is as follows:

[0053]

[0054] in, This represents the coordinates of the origin of the polar coordinate system in the global rectangular coordinate system. Through the above mapping, the polar coordinates of each structural node can be systematically converted into the corresponding rectangular coordinates, thus obtaining the set of rectangular coordinates P of the structural nodes.

[0055] Step S205: Calculate the coordinates of the constraint nodes based on the set of structural node coordinates, and generate the set of constraint node coordinates.

[0056] It should be noted that step S205 includes: calculating the local tangent vector at each structural node based on the set of structural node coordinates; rotating the local tangent vector and normalizing it to obtain the unit outward normal vector; and calculating the constraint node coordinates corresponding to each structural node based on the unit outward normal vector and according to the preset offset distance to generate the constraint node coordinate set.

[0057] The local tangent vector is the direction vector tangent to the contour line at a structural node. The unit outward normal vector is a unit-length vector perpendicular to the contour line and pointing outward from the structure at a structural node; it can be obtained by rotating the local tangent vector by 90 degrees and normalizing it. The offset distance represents the distance the constraint node needs to move outward from the structural node along the outward normal direction. The constraint node coordinates are calculated based on the structural node coordinates, the unit outward normal vector, and the offset distance, and are used to define the boundary conditions in the finite element model.

[0058] For example, to achieve self-constraint in the model, it is necessary to determine the coordinates of the constraint nodes corresponding to the structural elements, which are calculated using vectors, such as... Figure 5 As shown, with Indicates the lining structure node, with Represents the constraint nodes. Based on the calculated set of node coordinates... ,in Establish each node The neighbor index for each node Calculate the local tangent vector of the line connecting its adjacent points. , is represented as:

[0059]

[0060] in, Representation Nodes Local geometric features at the location, Represents a node The next node, Represents a node The previous node. The tangent vector Rotating counterclockwise by 90° yields the corresponding external normal vector, represented as:

[0061]

[0062] We can normalize the outward normal vector by calculating and normalizing its L2 norm, as follows:

[0063] The set of coordinate positions of the corresponding constraint nodes is calculated by combining the set of node coordinates. , is represented as:

[0064] in, This represents the distance of one unit.

[0065] In this embodiment, by establishing a unified global rectangular coordinate system and analyzing geometric logic to determine each local polar coordinate system, the problems of inconsistent reference systems and cumbersome and error-prone coordinate calculations in complex multi-centered sections are solved, achieving a systematic and accurate conversion from geometric parameters to node coordinates. By discretizing based on the principle of equal arc length and automatically calculating the polar angle increment on each arc segment according to the standard arc length, the problem of uneven element size and impact on calculation accuracy caused by manual mesh generation is solved, achieving standardization and consistency in mesh generation and laying the foundation for subsequent high-precision finite element analysis. By calculating the local tangent vector and unit outward normal vector and automatically generating constraint node coordinates based on a preset offset distance, the problem of boundary condition application relying on manual judgment and inaccurate positioning is solved, achieving precise and automated positioning of constraint nodes, thereby ensuring the realism and reliability of the finite element model boundary simulation.

[0066] In the third embodiment, step S30 includes: Step S301: Based on the set of structural node coordinates and the set of constraint node coordinates, a finite element model is generated through ordered pair encapsulation and sequential modeling strategies. The finite element model includes structural elements and constraint spring elements.

[0067] It should be noted that ordered pair encapsulation can be understood as a data organization method that binds a structural node with its corresponding constraint node, as well as the properties of the spring elements to be created between them, to form a complete data unit. Sequential modeling strategies can be understood as a method of constructing model elements in a specific order, thereby ensuring that the element creation order is consistent with the geometric topology.

[0068] Step S301 includes: defining each structural node and its corresponding constraint node as a node pair based on the set of structural node coordinates and the set of constraint node coordinates; encapsulating each node pair with its corresponding spring constraint attribute to form multiple ordered number pair units; sorting the multiple ordered number pair units along the tunnel contour in a preset direction to form an ordered sequence; reading the ordered sequence and creating structural units and constraint spring units in batches according to the encapsulated spring constraint attribute in the sequence order.

[0069] It should be noted that structural elements are elements representing the tunnel lining body in the finite element model, such as beam elements or shell elements, and their nodes are structural nodes. Constrained spring elements are special elements used to simulate the interaction between the surrounding rock and the lining. For example, spring elements can connect structural nodes and constraint nodes to characterize the elastic constraints of the foundation.

[0070] For example, each structural node that needs to establish a connection... and its corresponding constraint nodes Defined as an independent pair of nodes, such as Figure 6 As shown. Then, the node is encapsulated with specific spring constraint properties to form a complete ordered pair of elements. All the encapsulated ordered pairs of elements are then sorted counter-clockwise from the vault top to form an ordered sequence. The program then automatically reads this ordered sequence and, strictly according to its order, creates structural elements and constraint spring elements based on their defined spring properties. This process avoids the association errors, omissions, or sequence confusion that may occur in traditional manual modeling.

[0071] Step S302: Based on the predefined load conditions and the node coordinates in the finite element model, define the load case and apply the defined load case to the finite element model to obtain the processed finite element model.

[0072] It should be noted that predefined load conditions refer to predefined external forces or loads applied to the structure, such as surrounding rock pressure and water pressure. A load case is a set of information specifically defined regarding the magnitude, direction, and location of the load, based on the load conditions and the node coordinates of the finite element model.

[0073] Step S303: Perform internal force analysis on the processed finite element model to obtain the internal force analysis results.

[0074] It should be noted that mechanical calculations can be performed on finite element models with applied loads and constraints to solve for internal forces within the structure, such as axial force, shear force, and bending moment. The internal force analysis results are a set of data on the internal force values ​​of each section of the structure obtained after the internal force analysis.

[0075] In this embodiment, by encapsulating structural nodes, constraint nodes, and spring properties in ordered pairs and generating elements in batches according to a sequential modeling strategy, the inefficiency and node connection errors of manually creating elements one by one are solved, achieving efficient and automated assembly of the finite element model. By automatically defining load cases based on predefined load conditions and node coordinates, the cumbersome and error-prone manual mapping of loads to node positions is resolved, enabling precise and rapid load application and ensuring the realism of the analysis model. Finally, by performing internal force analysis on the complete model, the structural response can be automatically and accurately obtained, solving the reliability issues caused by traditional methods relying on simplified calculations or empirical estimations. This provides a precise data foundation for subsequent scientific reinforcement design, achieving high-precision analysis from geometric parameters to internal force results.

[0076] Based on the third embodiment, in one implementation, step S302 includes: traversing the node coordinates in the finite element model, identifying and grouping them based on their coordinate positions to form different load application node sets; and calling the load application command of the finite element solver through the program interface to apply predefined load values ​​in batches to the corresponding load application node sets.

[0077] It should be noted that the steps of traversing the node coordinates in the finite element model, identifying and grouping them based on their coordinate positions to form different load application node sets include: traversing the node coordinates in the finite element model, comparing the ordinate of the node with the ordinate of the rightmost node of the tunnel structure, and selecting the node set that bears the vertical load; and selecting the node set that bears the horizontal load in different directions based on the direction of the node on the y-axis of the global rectangular coordinate system.

[0078] An exemplary schematic diagram of the tunnel lining structure calculation is shown below. Figure 7 As shown, where Indicates vertical load. Indicates horizontal load. This represents the y-value of the rightmost node in the tunnel structure. By writing a Python script to traverse and filter all nodes in the finite element model, the nodes can be divided into three sets according to the applied load: those with a y-coordinate greater than... The nodes on the right and left of the y-axis provide precise target objects for subsequent load application. Based on the load application node set, the ANSYS load application command is invoked using Python. Through a loop, predefined load values ​​are applied to each node in this node set, where nodes with a y-axis greater than [a certain value] are [applied]. A downward vertical load is applied to the nodes, a leftward horizontal load is applied to the nodes to the right of the y-axis, and a rightward horizontal load is applied to the nodes to the left of the y-axis, thus completing the construction of the entire load case.

[0079] In this embodiment, by traversing node coordinates and automatically identifying and grouping them based on coordinate positions, the system can accurately divide the node sets bearing different types of loads according to the spatial distribution of nodes. This solves the problem of low efficiency and high error rate of manually selecting nodes based on experience, and achieves rapid and accurate definition of load application objects. By calling the load application command of the finite element solver through the program interface, predefined load values ​​are applied in batches to the corresponding node sets. This solves the tedious problem of manually selecting nodes one by one in the graphical interface to apply loads, eliminates human errors such as omissions or incorrect applications, significantly improves the efficiency and reliability of preprocessing, facilitates parametric analysis and optimization design, and achieves complete automation and high accuracy in load case definition.

[0080] In the fourth embodiment, step S40 includes: Step S401: Discretize the reinforcement ratio design range into multiple candidate reinforcement ratio levels.

[0081] It should be noted that the reinforcement ratio design range refers to the upper and lower limits of the possible values ​​of the tunnel lining reinforcement ratio determined according to design specifications and experience, covering the range from the minimum allowable reinforcement ratio to the maximum economic reinforcement ratio. Candidate reinforcement ratio levels can be understood as multiple specific reinforcement ratio values ​​obtained by discretizing the reinforcement ratio design range at certain intervals, with each value representing a design scheme to be evaluated.

[0082] Step S402: For each candidate reinforcement ratio level, calculate the safety factor distribution of the structure based on the internal force analysis results, and extract the minimum safety factor from the safety factor distribution.

[0083] It should be noted that, for a given candidate reinforcement ratio, the safety factor distribution can be understood as the set of safety factors for each section of the tunnel lining calculated based on internal force analysis results, reflecting the safety margin of the structure at different locations. The minimum safety factor refers to the minimum value extracted from the safety factor distribution, representing the safety level of the weakest link in the structure under this reinforcement ratio scheme.

[0084] Step S403: Compare the minimum safety factor with the preset safety factor threshold to select candidate reinforcement ratio schemes. The candidate reinforcement ratio schemes meet the preset safety requirements.

[0085] It should be noted that the preset safety factor threshold is a minimum safety factor value pre-set according to design specifications or safety requirements, used to determine whether the reinforcement scheme is qualified. The candidate reinforcement ratio scheme is a set of reinforcement ratio levels that meet the safety requirements after comparing the minimum safety factor with the preset threshold, which can be understood as a preliminary feasible design scheme.

[0086] Step S404: Using the minimum reinforcement ratio as the screening criterion, a second screening of candidate reinforcement ratio schemes is performed to obtain the target reinforcement scheme.

[0087] It should be noted that the minimum reinforcement ratio is the smallest reinforcement ratio among the candidate reinforcement ratio schemes. The target reinforcement scheme is the final reinforcement design obtained from the secondary screening of candidate schemes.

[0088] For example, the feasible design range of reinforcement ratio can first be discretized into 10 representative values ​​to form a set of discrete reinforcement ratio levels. For each reinforcement ratio value, the internal forces obtained through finite element analysis are used to obtain a safety factor distribution cloud map of the structure under the corresponding reinforcement conditions. Based on this, the minimum safety factor of all structural units under each reinforcement ratio is extracted and compared with the minimum safety factor threshold specified in the current code. Finally, all reinforcement ratio schemes that meet the code requirements for the minimum safety factor of all structural units are selected, and the scheme with the smallest reinforcement ratio is chosen. This scheme, while strictly adhering to design and safety codes, minimizes the amount of steel used and improves the economy of the scheme. The optimal reinforcement ratio that balances economy and safety is selected as the final design result. Furthermore, the complete finite element model is saved as a .db binary database file, and the internal force diagram and safety factor diagram of the lining structure are exported.

[0089] In this embodiment, the reinforcement ratio design range is discretized into multiple candidate levels, solving the problem of blindness in traditional design relying on manual experience to select a single reinforcement ratio for trial calculations. This achieves a systematic scan of the design space, avoiding omissions of solutions. By calculating the safety factor distribution for each candidate reinforcement ratio and extracting the minimum safety factor, the shortcomings of traditional methods that only focus on local sections and cannot quantify overall safety weaknesses are addressed, enabling accurate assessment of the overall structural safety. By automatically comparing the minimum safety factor with a preset threshold to filter candidate solutions, the subjectivity and inefficiency of manual judgment on safety are resolved, ensuring that all solutions meet the requirements of the specifications. Finally, a secondary screening is performed using the minimum reinforcement ratio as the standard, solving the economic decision-making problem of optimizing among multiple feasible solutions. This achieves automatic cost optimization under the premise of safety, thereby significantly improving the scientificity and efficiency of reinforcement design.

[0090] Based on the above embodiments and implementation methods, specifically, the cross-sectional shape of the tunnel can be selected as a four-centered circle, wherein the radius of the arch arc is... , radius of the side wall arc Corner radius , radius of the inverted arch Central angle of the vault Central corner of the side wall and the central angle The lining is classified as Class V, with a thickness of 0.5 meters. C30 grade concrete is used. The task is to analyze the internal forces of the lining structure and generate a model file. The specific structural form is as follows: Figure 8 As shown. Using the methods described in the above embodiments and implementations, the corresponding safety factor distribution cloud map is obtained, and the minimum safety factor of all structural units is extracted, and the corresponding bar chart is drawn. (Refer to...) Figure 9 Next, the minimum safety factor of each scheme is compared with the standard threshold, and all compliant schemes are selected. For example, a minimum safety factor greater than 2.8 is required, so scheme group 5 with a reinforcement ratio of 0.7% is selected as the design result, and the complete finite element model (.db file), internal force diagram of the lining structure, and safety factor diagram are output, as shown below. Figure 10 As can be seen, the areas with the lowest safety factor are generally the arch and the top and bottom of the side walls. In actual engineering, these areas can be locally reinforced.

[0091] Based on the same inventive concept, such as Figure 11 As shown, this application also provides a device for generating a tunnel lining structure, the device comprising: Parameter acquisition module 10 is used to acquire the geometric parameters of the four-centered circular cross-section through a data interface; The coordinate generation module 20 is used to construct a multivariate polar coordinate system based on the geometric parameters of the four-centered circular cross section, and to perform coordinate calculations based on the multivariate polar coordinate system to generate a set of structural node coordinates and a set of constraint node coordinates. The internal force analysis module 30 is used to construct a finite element model based on the set of coordinates of the structural nodes and the set of coordinates of the constraint nodes, and to perform internal force analysis on the finite element model to obtain the internal force analysis results. The scheme output module 40 is used to output a target reinforcement scheme based on the internal force analysis results, through discretized reinforcement ratio analysis and safety factor evaluation, and generate a tunnel lining structure based on the target reinforcement scheme.

[0092] It should be noted that the tunnel lining structure generation device provided in this application embodiment and the tunnel lining structure generation method provided in this application embodiment are based on the same application concept. Therefore, the specific implementation of this embodiment can refer to the implementation of the aforementioned tunnel lining structure generation method, and the repeated parts will not be described again.

[0093] Those skilled in the art will understand that the features described in the various embodiments of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application. Therefore, the scope of this application should not be limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method of generating a tunnel lining structure, characterized by, The method comprises: obtaining four-center circle section geometric parameters through a data interface; constructing a multi-element polar coordinate system based on the four-center circle section geometric parameters, and performing coordinate calculation based on the multi-element polar coordinate system to generate a structure node coordinate set and a constraint node coordinate set; constructing a finite element model based on the structure node coordinate set and the constraint node coordinate set, and performing internal force analysis on the finite element model to obtain an internal force analysis result; based on the internal force analysis result, performing discretization reinforcement ratio analysis and safety factor evaluation to output a target reinforcement scheme, and generating a tunnel lining structure based on the target reinforcement scheme.

2. The method of claim 1, wherein, The step of constructing a multi-element polar coordinate system based on the four-center circle section geometric parameters, and performing coordinate calculation based on the multi-element polar coordinate system to generate a structure node coordinate set and a constraint node coordinate set comprises: establishing a global rectangular coordinate system with the center of the vault circle arc as the origin; based on the four-center circle section geometric parameters, analyzing the topological relationship and geometric logic of each arc segment, and sequentially calculating the coordinates of the centers of the remaining arc segments in the global rectangular coordinate system, and establishing corresponding local polar coordinate systems; based on the equal arc length principle, discretizing the tunnel contour to determine the polar angles of the discrete points; combining the local polar coordinate systems and the polar angles of the discrete points, calculating the rectangular coordinates of each structure node to generate a structure node coordinate set; calculating the constraint node coordinates based on the structure node coordinate set, and generating a constraint node coordinate set.

3. The method of claim 2, wherein, The step of discretizing the tunnel contour based on the equal arc length principle to determine the polar angles of the discrete points comprises: obtaining the total arc length of the tunnel contour and the predetermined number of discrete units; calculating the standard arc length of each unit according to the total arc length of the tunnel contour and the predetermined number of discrete units; for each arc segment, calculating the polar angle increment of each discrete point relative to the origin of the local polar coordinate system based on the radius of each arc segment and the standard arc length, to obtain the polar angle of each discrete point.

4. The method of claim 2, wherein, The step of calculating the constraint node coordinates based on the structure node coordinate set, and generating a constraint node coordinate set comprises: based on the structure node coordinate set, calculating the local tangent vector at each structure node; rotating and unitizing the local tangent vector to obtain a unit external normal vector; based on the unit external normal vector, calculating the constraint node coordinates corresponding to each structure node according to a predetermined offset distance to generate a constraint node coordinate set.

5. The method of claim 1, wherein, The step of constructing a finite element model based on the structure node coordinate set and the constraint node coordinate set, and performing internal force analysis on the finite element model to obtain an internal force analysis result comprises: based on the structure node coordinate set and the constraint node coordinate set, generating a finite element model through ordered number encapsulation and sequential modeling strategy, the finite element model comprising structure units and constraint spring units; defining load cases based on predefined load conditions and node coordinates in the finite element model, and applying the defined load cases to the finite element model to obtain a processed finite element model; performing internal force analysis on the processed finite element model to obtain an internal force analysis result.

6. The method of claim 5, wherein, The step of generating a finite element model based on the structure node coordinate set and the constraint node coordinate set through an ordered pair encapsulation and sequential modeling strategy includes: Defining each structure node and its corresponding constraint node as a node pair based on the structure node coordinate set and the constraint node coordinate set; Encapsulating each node pair and its corresponding spring constraint attribute to form multiple ordered pair units; Sorting the multiple ordered pair units along the tunnel contour in a preset direction to form an ordered sequence; Reading the ordered sequence and creating structure units and constraint spring units in batch according to the sequence order based on the encapsulated spring constraint attribute.

7. The method of claim 5, wherein, The step of defining a load case based on a predefined load condition and the node coordinates in the finite element model and applying the defined load case to the finite element model to obtain a processed finite element model includes: Iterating through the node coordinates in the finite element model, identifying and grouping based on the coordinate positions to form different load application node sets; Calling a load application command of a finite element solver through a program interface to apply a predefined load value to the corresponding load application node set in batch.

8. The method of claim 7, wherein, The step of iterating through the node coordinates in the finite element model, identifying and grouping based on the coordinate positions to form different load application node sets includes: Iterating through the node coordinates in the finite element model, comparing the longitudinal coordinates of the nodes with the longitudinal coordinates of the rightmost nodes of the tunnel structure to filter out a node set bearing vertical load; Filtering out node sets bearing horizontal load in different directions according to the direction of the nodes in the global rectangular coordinate system y-axis.

9. The method of claim 1, wherein, The step of outputting a target reinforcement scheme based on the internal force analysis result through discretization of reinforcement ratio analysis and safety factor evaluation includes: Discretizing the reinforcement ratio design range into multiple candidate reinforcement ratio levels; For each candidate reinforcement ratio level, calculating the safety factor distribution of the structure based on the internal force analysis result and extracting the minimum safety factor from the safety factor distribution; Comparing the minimum safety factor with a preset safety factor threshold to filter out a candidate reinforcement ratio scheme that meets the preset safety requirement; Taking the minimum reinforcement ratio as a filtering criterion to perform secondary filtering on the candidate reinforcement ratio scheme to obtain a target reinforcement scheme.

10. A device for generating a tunnel lining structure, characterized in that The tunnel lining structure generation device includes: A parameter acquisition module configured to acquire four-center circle cross-section geometric parameters through a data interface; A coordinate generation module configured to construct a multi-element polar coordinate system based on the four-center circle cross-section geometric parameters and perform coordinate calculation based on the multi-element polar coordinate system to generate a structure node coordinate set and a constraint node coordinate set; An internal force analysis module configured to construct a finite element model based on the structure node coordinate set and the constraint node coordinate set and perform internal force analysis on the finite element model to obtain an internal force analysis result; A scheme output module configured to output a target reinforcement scheme based on the internal force analysis result through discretization of reinforcement ratio analysis and safety factor evaluation and generate a tunnel lining structure based on the target reinforcement scheme.

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