Numerical calculation method and device for simulating segment and internal steel slip

Abstract

The present application relates to a kind of numerical calculation method and device for simulating segment and built-in steel bar slip.The numerical calculation method for simulating segment and built-in steel bar slip described in the present application comprises: according to reinforcement information, grid division is carried out to three-dimensional shield segment, and the basic physical parameters of concrete are given to the grid three-dimensional shield segment, and cable element is arranged along actual muscle position, coupling is carried out to calibration bonding parameter and concrete model, and the concrete model with slip characteristics is obtained;Load path consistent with engineering scene is applied to the concrete model with slip characteristics, nonlinear incremental iteration is solved, and simulation time data is obtained;Finally, index calculation and evaluation are carried out to simulation time data.The numerical calculation method for simulating segment and built-in steel bar slip described in the present application effectively avoids the problem of stiffness and bearing capacity overestimation caused by the assumption of complete bonding.

Description

Technical Field

[0001] This invention relates to the field of numerical simulation of lining structures with bond-slip characteristics, and in particular to a numerical calculation method, numerical calculation device, electronic device and computer storage medium for simulating the slippage between segments and internal reinforcing bars. Background Technology

[0002] Numerical simulation is an indispensable method in engineering structural design and analysis. Through numerical calculations, the stress, deformation, and damage evolution of a structure can be predicted during the design phase, thus providing support for structural safety assessment. Common numerical simulation methods include the Finite Element Method (FEM) and the Finite Difference Method (FDM), both of which fall under the category of numerical simulation of continuous media. Specifically, they can reproduce the crack development, stiffness degradation, and damage propagation process of concrete under external loads in a virtual environment, thereby verifying the rationality of the structural design and assessing its safety margin.

[0003] In existing technologies, numerical simulations typically employ incremental loading and nonlinear solution methods. By gradually applying external loads and iteratively calculating the structural response at each loading step, indices such as stress-strain distribution, stiffness changes, and ultimate bearing capacity of concrete and reinforcing steel at various stages can be obtained. To handle the interaction between reinforcing steel and concrete, a common approach is to model the reinforcing steel as beam elements, assuming complete bond and no relative slippage between them and the concrete. To further simulate slippage effects, interface or contact elements need to be introduced between the reinforcing steel and concrete to represent their relative motion.

[0004] However, existing simulation methods have limitations under certain specific structural conditions. Taking the segment structure of underground shield tunnels as an example, such structures are often accompanied by large bending moments during the stress process. Their mechanical characteristics can be approximated as the stress behavior of a curved beam under bending loading. When the steel-concrete interface reaches a certain stress or strain level, relative slip may occur (i.e., the steel bars are displaced relative to the concrete). This slip weakens the constraint effect of the steel bars on crack closure, changes the force transmission mechanism, thereby accelerating concrete cracking and damage evolution, and affecting the development trend of damage variables in the Concrete Damage Plasticity (CDP) model.

[0005] Furthermore, existing technologies often neglect the slip effect at the steel-concrete interface, which may lead to an overestimation of the overall stiffness and bearing capacity of the tunnel segments in underground shield tunnels. Even when slip is recognized in some research or engineering practice, it is very difficult to accurately incorporate it into the finite element model: on the one hand, special elements or contact algorithms need to be introduced for the interface performance, and accurate bond-slip constitutive parameters need to be provided; on the other hand, the presence of interface slip increases the nonlinearity and computational complexity of the model, and more experimental data are required as support.

[0006] Therefore, existing technologies have a technical problem when performing numerical simulations on shield tunnel segment structures: the failure to consider interface slippage leads to inaccurate stiffness and bearing capacity assessments, resulting in misjudgments of the actual stress performance of the segments and affecting the reliability of safety assessments. Summary of the Invention

[0007] Based on this, the purpose of the present invention is to provide a numerical calculation method for simulating the slippage of tunnel segments and internal reinforcing bars.

[0008] A numerical calculation method for simulating slippage between tunnel segments and internal reinforcing bars includes the following steps:

[0009] S1: Mesh the three-dimensional shield tunnel segments according to the reinforcement information to obtain the initial concrete model;

[0010] S2: Construct cable elements and embed them, along with the calibrated bond parameters, into the initialized concrete model to obtain a concrete model with slip characteristics;

[0011] S3: Based on the preset load, perform incremental iterations on the concrete model with slip characteristics to obtain simulation time history data;

[0012] S4: Calculate and evaluate the performance indicators of the simulation time history data to obtain the current performance evaluation data of the tunnel lining segments.

[0013] The numerical calculation method for simulating slippage between tunnel segments and internal reinforcing bars described in this invention, compared to existing technologies, explicitly introduces the bond-slip effect at the reinforcement-concrete interface by replacing the reinforcement paths in the concrete with cable elements. This effectively avoids the problem of overestimating stiffness and bearing capacity caused by assuming complete bond. Furthermore, since the cable elements themselves can characterize axial force and slippage, there is no need to introduce additional beam and interface element combinations for modeling, thereby reducing the number of interface couplings, lowering the complexity of parameter settings and contact calculations, and improving the convergence and stability of the numerical simulation.

[0014] Furthermore, the embedding into the initial concrete model includes the following sub-steps:

[0015] The reinforcement layout path in the initial concrete model is converted into computable cable elements, forming a concrete model containing cable elements.

[0016] Next, based on the basic physical parameters and calibration bond parameters of the reinforcing bars, values ​​are assigned to the cable elements in the concrete model containing cable elements to form a reinforced concrete model with stress response characteristics.

[0017] Accordingly, this invention transforms the reinforcement arrangement path in shield tunnel segments into cable elements and assigns values ​​based on the physical parameters of the reinforcement foundation and the calibrated bond parameters. This explicitly reflects the force transmission and slip characteristics of the reinforcement-concrete interface, avoiding the parameter inconsistencies and convergence difficulties that exist in traditional beam and interface element combination modeling. This effectively simplifies the modeling process and improves the stability and controllability of numerical simulation. Especially for shield tunnel segment structures, due to their complex reinforcement configuration and potential for large strain under bending conditions, neglecting the slip effect at the reinforcement-concrete interface can easily lead to calculation results deviating from reality. Therefore, by introducing cable elements, the slip effect can be realistically reflected under complex reinforcement and large strain conditions, making it more suitable for numerical simulation and performance evaluation of shield tunnel segment structures.

[0018] Furthermore, the calibrated bonding parameters include cohesive strength, friction angle, shear stiffness, residual cohesive strength, critical slip, and residual initial slip, which are specifically obtained through the following steps:

[0019] First, based on the single-rib pull-out test, mechanical data sets were collected during the pull-out process to form load-slip curves and stress-strain curves;

[0020] Meanwhile, based on the initial concrete model, cable elements are introduced and a set of intermediate bond parameters to be optimized are assigned to them. The numerical simulation platform is used to perform incremental iterative calculations on the single-reinforcement pull-out condition to obtain the corresponding simulated load-slip curves.

[0021] The intermediate binding parameters refer to the set of intermediate parameters that have not yet been fully iterated, and are specifically represented as follows:

[0022]

[0023] In the formula, θ represents the intermediate bonding parameter; τ c Indicates cohesive strength; Indicates the angle of friction; K s τ represents shear stiffness. res Indicates residual cohesive strength; δ c Indicates critical slip; δ res Indicates residual initiation slip;

[0024] The incremental iterative calculation refers to gradually applying displacement loads in a numerical simulation platform and solving the response of the steel-concrete interface at each loading step to obtain the simulated load-slip curve.

[0025] Then, the deviation value of the simulated load-slip curve and the corresponding load-slip curve in the mechanical dataset is calculated using the objective function to obtain the deviation value of the current intermediate bond parameters;

[0026] Subsequently, it is determined whether the deviation value of the current intermediate bonding parameter meets the iteration threshold: if not, it is considered that the current intermediate bonding parameter has not converged, an optimization algorithm is called to update the current intermediate bonding parameter to obtain the updated intermediate bonding parameter, and incremental iteration calculation continues; if yes, it is considered that the current intermediate bonding parameter has been calibrated and is used as the calibration bonding parameter.

[0027] Accordingly, this invention collects mechanical data of the steel-concrete interface based on single-reinforcement pull-out tests, and combines numerical inversion and optimization iteration to obtain a set of calibrated bonding parameters that can reflect the stress law of the steel-concrete interface in the three stages of initial bonding, slip development and residual friction. This ensures the authenticity and reproducibility of the numerical model input parameters and effectively improves the ability of numerical simulation to characterize the entire slip process between steel and concrete.

[0028] Furthermore, the objective function is specifically represented as follows:

[0029]

[0030] In the formula, J(θ) (t) ) represents the intermediate bonding parameter θ in the t-th iteration. (t) The corresponding deviation value; E bond The objective function for the initial bonding stage is expressed as follows:

[0031]

[0032] In the formula, N1 represents the total number of sampling points in the initial bonding stage; I(·) represents the indicator function, which outputs 1 when the condition is met and 0 otherwise. P represents the critical slip corresponding to the intermediate bonding parameters in the t-th iteration; sim (δ i ;θ (t) ) represents the slip δ that propels the end displacement to the i-th sampling point through numerical simulation under the intermediate bonding parameters of the t-th iteration. i The load obtained from the model reaction force at that time;

[0033] E slipThe objective function representing the slip development stage is calculated as follows:

[0034]

[0035] In the formula, N2 represents the total number of sampling points in the slip development stage; P represents the residual initiation slip corresponding to the intermediate bonding parameters in the t-th iteration; exp (δ i ) represents the slip amount δ in the mechanics dataset. i At that time, the corresponding load; P ref Indicates the normalized reference value;

[0036] E res The objective function representing the residual friction stage is calculated as follows:

[0037]

[0038] In the formula, N2 represents the total number of sampling points in the slip development stage;

[0039] Indicates the boundary penalty term; This represents the experimental critical slip directly identified from the load-slip curve of a single-rib pull-out test; The residual initiation slip identified by the load-slip curve of the single-rib pull-out test; λ c and λ res These are dimensionless weighting coefficients.

[0040] Accordingly, this invention divides the stress process of the reinforced concrete interface into three stages: initial bonding, slip development, and residual friction, by introducing a phased error term and a boundary penalty term into the objective function. The deviation between the simulated and experimental curves for each stage is calculated. Simultaneously, by adding boundary penalty terms for critical slip and residual initial slip to the objective function, consistency between the numerical simulation output curve and the experimental curve is ensured at the stage transition points. Therefore, this invention not only avoids mismatch phenomena under overall curve fitting but also ensures that the simulation process can truly reflect the mechanical evolution of the entire interface slip process, thereby improving the accuracy of parameter calibration and the reliability of numerical simulation.

[0041] A numerical calculation device for simulating the slippage between tunnel segments and built-in reinforcing bars includes a shield tunnel segment concrete mesh division unit, a cable unit embedding unit, a load simulation unit, and a shield tunnel segment performance evaluation unit.

[0042] The shield tunnel segment concrete mesh division unit is used to divide the three-dimensional shield tunnel segment into meshes according to the reinforcement information to obtain the initial concrete model.

[0043] The cable unit embedding unit is used to construct cable units and embed them, along with the calibrated bonding parameters, into the initialized concrete model to obtain a concrete model with slip characteristics.

[0044] The load simulation unit is used to incrementally iterate on a concrete model with slip characteristics according to a preset load to obtain simulation time history data.

[0045] The shield tunnel segment performance evaluation unit is used to calculate and evaluate the indicators of the simulation time history data to obtain the current shield tunnel segment performance evaluation data.

[0046] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0047] Figure 1 This is a simplified structural diagram of the numerical calculation device for simulating the slippage between tunnel segments and internal reinforcing bars as described in this invention;

[0048] Figure 2 This is a simplified flowchart illustrating the numerical calculation method for simulating the slippage between tunnel segments and internal reinforcing bars as described in this invention.

[0049] Figure 3 This is a schematic diagram comparing the load-displacement curves obtained from the concrete model with slip characteristics constructed in this invention under damage loading conditions with experimental results.

[0050] Figure 4 This is a schematic diagram comparing the load-displacement curves obtained by the concrete model with sliding characteristics constructed in this invention under the ultimate bearing capacity condition of shield tunnel segments with those obtained by a full-scale loading experiment. Detailed Implementation

[0051] To address the problem of inaccurate stiffness and bearing capacity assessments in existing numerical simulations of tunnel boring machine (TBM) segments due to the lack of consideration for interface slip, this invention first meshes the 3D TBM segments based on reinforcement information and assigns basic physical parameters of concrete to the meshed 3D TBM segments, forming a computable initial concrete model. Then, cable elements arranged along the actual reinforcement locations are constructed and embedded into the initial concrete model along with calibrated bond parameters to characterize the force transmission and relative displacement between the reinforcement and concrete, resulting in a concrete model with slip characteristics. Based on this, a load path consistent with the engineering scenario is applied to the concrete model with slip characteristics, and a nonlinear incremental iterative solution is used to obtain simulation time history data. Finally, the simulation time history data is used to calculate and evaluate performance indicators, yielding the current performance evaluation data of the TBM segments.

[0052] Accordingly, by explicitly introducing cable elements to simulate the bond slip between steel bars and concrete, the overestimation of stiffness and bearing capacity caused by the assumption of complete bond is avoided, making the evaluation results closer to reality. At the same time, the cable elements combined with parametric interfaces replace the traditional combination of beam elements and explicit interface elements, reducing the risk of non-convergence caused by contact tolerance and parameter coupling, and effectively improving the controllability of modeling and calculation.

[0053] Based on the above design, this invention proposes a numerical calculation method for simulating the slippage between tunnel segments and internal reinforcing bars, and based on this method, proposes a numerical calculation device for simulating the slippage between tunnel segments and internal reinforcing bars.

[0054] Please also refer to Figure 1 and Figure 2 , Figure 1 This is a simplified structural diagram of the numerical calculation device for simulating the slippage between tunnel segments and internal reinforcing bars as described in this invention. Figure 2 This is a simplified flowchart illustrating the numerical calculation method for simulating the slippage between pipe segments and internal reinforcing bars as described in this invention.

[0055] The numerical calculation device for simulating the slippage of tunnel segments and built-in reinforcing bars includes a shield tunnel segment concrete mesh division unit 1, a cable unit embedding unit 2, a load simulation unit 3, and a shield tunnel segment performance evaluation unit 4.

[0056] The shield tunnel segment concrete mesh division unit 1 is used to perform step S1: divide the three-dimensional shield tunnel segment into meshes according to the reinforcement information to obtain the initial concrete model.

[0057] Specifically, the reinforcement information is a dataset describing the layout and mechanical performance parameters of the steel bars inside the shield tunnel segment. It typically includes the material type and strength grade of the steel bars, compressive yield, tensile yield, density, elastic modulus, geometric characteristics (including diameter and cross-sectional area), layout path (such as longitudinal, circumferential, and oblique), anchorage length, protective layer thickness, and geometric parameters such as design or construction allowable deviations. It serves as the geometric and mechanical input basis for the steel reinforcement structure and mainly determines the distribution path and quantity configuration of cable units. It is usually extracted from design drawings, reinforcement details, construction BIM models, or on-site measurement data.

[0058] The three-dimensional shield tunnel segment is a three-dimensional solid geometric model constructed based on the actual lining structure of the project. It is usually established using CAD or finite element preprocessing platforms and generally includes structural geometric parameters such as the inner radius, outer radius, thickness, ring width (longitudinal length), assembly angle (central angle), as well as openings and joints of the segment. It is used to define the volume domain and boundary domain of the concrete body. It can usually be directly modeled according to the design drawings or reconstructed from laser scanning / point cloud data after geometric simplification.

[0059] The mesh generation is used to combine the three-dimensional shield tunnel segments with reinforcement information, and further endow the concrete with material constitutive properties and boundary or monitoring set configurations to generate a numerical mesh model with finite element analysis capabilities, i.e., to form an initial concrete model. Its construction specifically includes the following sub-steps:

[0060] Based on the preset mesh feature length, the three-dimensional shield tunnel segments are meshed to form an initial finite element mesh model with multiple concrete mesh nodes.

[0061] The reinforcement layout path in the reinforcement information is imported into the initial finite element mesh model according to a unified coordinate system to form a finite element mesh model with the reinforcement layout path.

[0062] Based on the basic physical parameters of concrete, a concrete constitutive model is selected, constitutive values ​​are assigned to the finite element mesh model with reinforcement layout paths, and boundary or monitoring sets are constructed to form an initial concrete model.

[0063] The basic physical parameters of the concrete are assumed to be elastic modulus, Poisson's ratio, compressive strength and fracture energy; the concrete constitutive model is assumed to be the concrete damaged plasticity (CDP) model; the boundary or monitoring set includes the fixed support surface, the loading surface and the key response monitoring points.

[0064] It should be noted that, in addition to the concrete plastic damage model (CDP), other equivalent damage constitutive models or elastoplastic models can be selected according to engineering needs for the concrete material constitutive model; the boundary or monitoring set can also be defined according to different test conditions, loading methods or numerical simulation requirements, such as adding displacement constraint surfaces, setting different loading ports or setting more monitoring points; the reinforcement layout path can be set according to different reinforcement forms (such as longitudinal layout, circumferential layout, oblique layout or their combination), as well as different parameters such as reinforcement spacing, number of layers, and anchorage length; those skilled in the art can flexibly determine according to the specific engineering object and analysis objectives, and this invention does not limit the specific geometric modeling or parameter settings.

[0065] The cable unit embedding unit 2 is used to perform step S2: constructing cable units and embedding them with calibration bonding parameters into the initialized concrete model to obtain a concrete model with slip characteristics.

[0066] Generally, existing technologies for coupling steel reinforcement and concrete typically employ a combined modeling approach using beam and interface elements. While this method can describe the mechanical relationship between the reinforcement and concrete, it lacks a unified standard for parameter selection at different interfaces and is prone to convergence difficulties in numerical calculations under cyclic loading or complex boundary conditions. Furthermore, the combined modeling approach using beam and interface elements is difficult to couple effectively with the concrete plastic damage model (CDP), thus limiting the accurate simulation of the damage evolution process. Therefore, existing technologies are prone to significant deviations in stiffness and load-bearing capacity assessments for shield tunnel segments subjected to significant bending forces.

[0067] In addition, other existing technologies model both the reinforcing steel and concrete as solid elements and introduce interface elements between them to simulate slip. This method can reflect the interface effect to some extent in local analysis. However, due to the large number and complex arrangement of reinforcement in shield tunnel segments, introducing interface elements between solids not only involves a huge amount of modeling and calculation, but the slip behavior is often limited by the initial geometric model. For example, whether the interface geometry is complete and whether the geometric characteristics of the ribbed steel bars are considered will affect the accuracy and stability of the calculation results.

[0068] Based on this, the present invention uses cable elements as a modeling method for reinforcing bars. This not only explicitly reflects axial stress and bond-slip effect in one-dimensional elements, but also the slip process does not depend on the geometric integrity of the solid elements. Instead, it is directly realized through parametric control. Therefore, it is simpler to model, more stable in calculation, and more suitable for shield tunnel segments, which have complex reinforcement and significant bending.

[0069] Specifically, the embedding into the initialized concrete model includes the following sub-steps:

[0070] The reinforcement layout path in the initial concrete model is converted into computable cable elements to bear axial forces and reflect the relative slippage between the reinforcement and the concrete, thus forming a concrete model containing cable elements.

[0071] Next, based on the basic physical parameters and calibration bond parameters of the reinforcing bars, values ​​are assigned to the cable elements in the concrete model containing cable elements to form a reinforced concrete model with stress response characteristics.

[0072] The basic physical parameters of the reinforcing bars by default include the diameter of the reinforcing bars, the anchorage length, and the contact area;

[0073] The calibrated bond parameters are slip parameters obtained through calibration, specifically including cohesive strength, friction angle, shear stiffness, residual cohesive strength, critical slip, and residual initial slip. The calibration is performed by inverting the dataset collected through single-reinforcement pull-out tests to reflect the slip law at the interface between the steel reinforcement and concrete.

[0074] It should be noted that this invention no longer relies on the traditional mesh node coupling method, but instead borrows the modeling concept of cable elements for soil slopes, transforming the steel reinforcement paths arranged in concrete into cable elements. Simultaneously, as one-dimensional linear elements, cable elements can bear axial forces and explicitly reproduce the bond-slip relationship between steel reinforcement and concrete through parameter input, thus avoiding the introduction of additional interface elements. Similar to the principle of using soil slope anchors to simulate the relative slippage of the anchor-soil interface in slope stabilization, this invention applies this concept to shield tunnel segment modeling. By calibrating bond parameters, cable elements are endowed with properties such as cohesive strength, friction angle, and shear stiffness, enabling them to realistically reflect the entire slippage process of the steel reinforcement-concrete interface and its impact on overall mechanical properties.

[0075] Additionally, it should be noted that the slip behavior at the steel-concrete interface is a complex nonlinear problem that cannot be fully determined solely by theoretical formulas. Therefore, calibration is performed using experimental data. This involves obtaining the interface mechanical response curve through single-reinforcement pull-out tests and combining numerical inversion and parameter optimization iterations to obtain a set of calibration bond parameters that accurately reflect the slip behavior. The specific calibration steps are as follows:

[0076] First, based on the single-rib pull-out test, mechanical data sets were collected during the pull-out process to form load-slip curves and stress-strain curves, which are specifically represented as follows:

[0077] D={(δ i ,P i ,ε i ,σ i )|i=1,2,…,N}

[0078] In the formula, D represents the mechanical dataset; δ i P represents the end slip of the reinforcing bar at the i-th sampling point in a single-bar pull-out test, where N represents the total number of sampling points; i ε represents the pull-out load corresponding to the i-th sampling point in a single-rib pull-out test; i σ represents the local strain corresponding to the i-th sampling point in a single-rib pull-out test; i This represents the local stress corresponding to the i-th sampling point in a single-rib pull-out test.

[0079] Among them, the load-slip curve P(δ)={(δ) in the mechanical dataset i ,P iThe stress-strain curve σ(ε) = {i = 1, 2, ..., N} is related to the stress-strain curve σ(ε) = {i = 1, 2, ..., N}. i ,σ i The formula |i=1,2,…,N} is used to characterize the stress behavior of the reinforced concrete interface at different stages, including the initial bonding stage, the slip development stage, and the residual friction stage. This formula serves as the a priori range of values ​​for extracting characteristic parameters such as cohesive strength, friction angle, and shear stiffness, and as the initial input for the subsequent calibration process.

[0080] It should be noted that the single-reinforcement pull-out test can be carried out using the center pull-out test method. The test conditions can refer to the relevant provisions of the "Standard for Test Methods of Concrete Structures" (GB / T 50152—2012). It usually requires multiple sets of tests (such as 36 sets) to ensure the statistical stability of the parameters. At the same time, the concrete specimens are generally made into cubes, with common sizes of 160mm×160mm×160mm and 250mm×250mm×250mm. In addition, to ensure that the interface effect can be fully developed, the side length of the specimen is defaulted to 10 times the diameter of the reinforcing bar, and the bond length of the reinforcing bar in the concrete is defaulted to 5 times the diameter of the reinforcing bar. Through the above settings, the stability and validity of the mechanical data set are ensured, providing a reliable basis for subsequent numerical simulation calibration.

[0081] Meanwhile, based on the initial concrete model, cable elements are introduced and assigned a set of intermediate bond parameters to be optimized. The numerical simulation platform is used to perform incremental iterative calculations on the pull-out condition of a single reinforcement to obtain the corresponding simulated load-slip curve.

[0082] The intermediate bonding parameters refer to the set of intermediate parameters that have not yet been fully iterated. Their initial values ​​are obtained by setting them within the characteristic range of the load-slip curve and stress-strain curve in the mechanical dataset. Then, they are iteratively updated to gradually approximate the true bonding parameters. The specific representation of the intermediate bonding parameters can be found in the following expression:

[0083]

[0084] In the formula, θ represents the intermediate bonding parameter; τ c This represents the cohesive strength, corresponding to the peak point of the load-slip curve; The friction angle is a parameter representing the relationship between the residual frictional intensity and the normal stress, used to characterize the frictional slip behavior; K s τ represents the shear stiffness, which is the tangent stiffness of the curve during the initial bonding stage; res δ represents the residual cohesive strength, the average interfacial shear stress corresponding to the plateau in the residual friction stage; c δ represents the critical slip, which is the amount of slip when the curve transitions from a linear rise to a peak point, and is used to characterize the critical point in the initial bonding stage;res Residual starting slip is the amount of slip when the load-slip curve drops from its peak and is about to enter the residual plateau; that is, the amount of slip at the starting point when entering the residual friction stage.

[0085] The incremental iterative calculation refers to gradually applying displacement loads in a numerical simulation platform and solving the response of the steel-concrete interface at each loading step to obtain the simulated load-slip curve.

[0086] Then, the deviation value between the simulated load-slip curve and the corresponding load-slip curve in the mechanical dataset is calculated using the objective function to obtain the deviation value of the current intermediate bond parameter. The specific calculation expression can be found in the following formula:

[0087]

[0088] In the formula, J(θ) (t) Let P be the objective function, representing the deviation value corresponding to the intermediate bonding parameters in the t-th iteration; sim (δ i ;θ (t) ) represents the slip δ that propels the end displacement to the i-th sampling point through numerical simulation under the intermediate bonding parameters of the t-th iteration. i At that time, the load obtained from the model reaction force; P exp (δ i ) represents the slip amount δ in the mechanics dataset. i At that time, the corresponding load; P ref To represent a normalized reference value, you can use max. j (P exp (δ j The peak value of the load-slip curve in the mechanical data set can also be represented by the relative error P. exp (δ i Alternatively, one could take 1 and not consider normalization, thus using the absolute value error method, etc. This invention does not specifically limit the selection of its normalization reference value.

[0089] In another embodiment, considering that the slip behavior between the steel reinforcement and concrete has an initial bond stage, a slip development stage, and a residual friction stage, the present invention uses a three-stage adaptive objective function to calculate the deviation value of the current intermediate bond parameters, which can be referred to in the following calculation expression:

[0090]

[0091] In the formula, E bond The objective function for the initial bonding stage measures the deviation between the simulated load-slip curve and the corresponding load-slip curve in the mechanical dataset. Its specific calculation can be found in the following expression:

[0092]

[0093] In the formula, N1 represents the total number of sampling points in the initial bonding stage; I(·) represents the indicator function, which outputs 1 when the condition is met and 0 otherwise. This represents the critical slip corresponding to the intermediate bonding parameters in the t-th iteration;

[0094] E slip The objective function representing the slip development stage measures the deviation between the simulated load-slip curve and the corresponding load-slip curve in the mechanical dataset. Its specific calculation can be found in the following expression:

[0095]

[0096] In the formula, N2 represents the total number of sampling points in the slip development stage; This represents the residual initiation slip corresponding to the intermediate bonding parameters in the t-th iteration;

[0097] E res The objective function for the residual friction stage measures the deviation between the simulated load-slip curve and the corresponding load-slip curve in the mechanical dataset. Its specific calculation can be found in the following expression:

[0098]

[0099] In the formula, N2 represents the total number of sampling points in the slip development stage;

[0100] The boundary penalty term is used to constrain the relative consistency between the numerical simulation curve and the experimental curve at different stages, that is, the relative consistency between the critical slip and the residual starting slip. In the actual iterative optimization process, if only the overall curve difference is minimized, it may cause the curve output by the numerical simulation to be misfitted with the curve of the mechanical dataset, that is, mismatch phenomenon. This causes the overall curve to seem to match, but there is a deviation at the stage inflection point. Therefore, the boundary penalty term is used to constrain the alignment between the critical slip and the residual starting slip, thereby alleviating the mismatch phenomenon.

[0101] This represents the experimental critical slip directly identified from the load-slip curve of a single-rib pull-out test; The residual initiation slip identified by the load-slip curve of the single-rib pull-out test; λ c and λ res These are dimensionless weighting coefficients used to adjust the proportion of the penalty term in the overall objective function, with a default value range of [0.01, 0.1].

[0102] Then, it is determined whether the deviation value of the current intermediate bonding parameter meets the iteration threshold: if not, it is considered that the current intermediate bonding parameter has not converged, and the optimization algorithm needs to be called to update the current intermediate bonding parameter to obtain the updated intermediate bonding parameter, and continue to perform incremental iteration calculation; if yes, it is considered that the current intermediate bonding parameter has been calibrated and is used as the calibration bonding parameter.

[0103] The iteration threshold can be specifically defined by the following judgment expression:

[0104]

[0105] In the formula, The relative error represents the deviation of the intermediate bonding parameter between two consecutive iterations, used to determine whether the optimization process tends to stabilize; ∈ represents the convergence threshold of the relative error, whose default value range is

[10] . -4 10 -2 ]; J min This represents the minimum allowable deviation value of the intermediate bonding parameter. When the deviation value of the intermediate bonding parameter falls to this minimum threshold, convergence is considered achieved. max This indicates the maximum number of iterations allowed, used to prevent the optimization process from getting stuck in infinite iterations. It is determined by computational resources and convergence speed.

[0106] The optimization algorithm employs Particle Swarm Optimization (PSO) to globally optimize the intermediate bonding parameters, gradually reducing the objective function to meet the iteration threshold. The global optimization of the intermediate bonding parameters for the (t+1)th iteration can be referenced in the following expression:

[0107]

[0108] In the formula, This represents the actual physical value of the d-th component in the i-th candidate solution during the (t+1)-th iteration, i.e. For any parameter in the search space, its candidate solution represents a combination of one of the candidate components of the intermediate binding parameter.

[0109] Let represent the normalized parameter value of the d-th component in the i-th candidate solution during the t-th iteration. Using normalized parameter values ​​avoids differences between different dimensionless values ​​and ensures that all parameter components are updated on a uniform scale. The specific calculation can be found in the following expression:

[0110]

[0111] In the formula, This represents the d-th component of the intermediate bonding parameter in the t-th iteration; and The lower and upper limits of the physical quantity corresponding to the d-th component of the intermediate bond parameter are determined by the curve characteristics or empirical boundaries obtained from the single-strand pull-out test, and are used to ensure that the parameter values ​​are within a reasonable physical feasible range.

[0112] The inertia term is used to ensure the continuity of the search and avoid prematurely getting trapped in local optima; its ω... (t) This represents the inertia weight for the t-th iteration, used to balance global search and local convergence, and gradually decreases with each iteration; This represents the velocity of the i-th candidate solution on the d-th component at the t-th iteration, i.e., the update step size of the normalized parameter value of that component, which is used to control the adjustment magnitude of the normalized parameter value of that component in the next iteration.

[0113] c1 represents the individual learning term, which guides the current candidate solution in the search space to approach the normalized parameter value of its historically best-performing component; c1 represents the individual learning factor, which adjusts the degree to which the normalized parameter value of the current component approaches its own historical best solution. This represents a uniformly random number in the interval [0,1] at the t-th iteration, to increase the randomness of the search; This represents the individual optimal normalized parameter value of the d-th component of the i-th candidate solution across all iteration histories.

[0114] c1 represents the group learning term, which is used to promote the normalized parameter value of the component that performs best in the group in the search space; c2 represents the group learning factor, which is used to adjust the degree to which the normalized parameter value of the current component approaches the global optimum. This represents a uniformly random number in the interval [0,1] at the t-th iteration; This represents the globally optimal normalized parameter value for the d-th component among all candidate solutions.

[0115] It should be noted that when the current intermediate binding parameter fails to meet the iteration threshold, it indicates that there is still room for improvement within the existing search range. Therefore, an optimization algorithm needs to be invoked to search for new potential solutions in the parameter space to serve as the intermediate binding parameter for the next iteration. In this case, the Particle Swarm Optimization (PSO) algorithm employed in this invention introduces a swarm search mechanism of candidate solutions into the parameter space, ensuring that each iteration not only relies on the local information of the current solution but also comprehensively considers the optimal performance of each candidate solution throughout the historical iterations.

[0116] During the search process of the optimization algorithm, each candidate solution represents a set of intermediate binding parameters. Its update direction is influenced by two factors: first, the candidate solution's own historical best value (individual best), reflecting the optimal performance it achieved in previous iterations, i.e., the lowest deviation value, thus ensuring the algorithm retains local optimum experience; second, the global best value of all candidate solutions in the iteration history (collective best), reflecting the optimal performance explored by the collective in the search space, thus ensuring the algorithm gradually approaches the optimal solution globally. Therefore, through the combined effects of the inertia term, individual learning term, and collective learning term, candidate solutions can dynamically adjust their update direction and magnitude in the search space to achieve a balance between exploration and convergence.

[0117] Accordingly, when the threshold condition is not met, this invention updates the parameter components of the candidate solution by calling an optimization algorithm, making the intermediate bonding parameters used in the next iteration closer to the global optimum. Numerical simulation and objective function calculation are then performed again under these parameters. This iterative process continues until the threshold condition is met or the maximum number of iterations is reached, ensuring that the selection of the calibration bonding parameters reflects both local characteristics and global rationality, thus guaranteeing the convergence and effectiveness of the optimization results.

[0118] The load simulation unit 3 is used to perform step S3: according to the preset load, incrementally iterate the concrete model with slip characteristics to obtain simulation time history data.

[0119] Specifically, the load is achieved by arranging loading blocks in the mid-span region of a parameter-complete concrete model and applying vertical displacement control boundary at a constant rate to realize displacement load, which is used to trigger the parameter-complete concrete model to enter the entire process from the elastic stage to cracking, damage and finally bearing capacity limit.

[0120] The incremental iteration refers to the numerical simulation platform applying displacement loads in small steps during the loading process, and updating the mechanical state inside the parameter-complete concrete model in each solution step. The mechanical state includes updating the tensile and compressive damage variables and stiffness degradation in the concrete plastic damage model (CDP), as well as updating the slip response of the cable element, which is jointly controlled by cohesive strength, friction angle and shear stiffness. This enables the concrete model to truly reflect the influence of interface bond degradation and relative slip on the redistribution of internal forces when entering the post-cracking stage, and thus output complete simulation time history data.

[0121] The simulation time history data is used to record the response results of the shield tunnel segments throughout the numerical simulation process. Specifically, it includes load-displacement curves, interface slip curves, axial force distribution of steel bars, concrete damage factor field, and displacement time history response of each key point during loading.

[0122] The load-displacement curve is used to reflect the overall stiffness change and ultimate bearing capacity of the concrete model, depicting the entire process from the elastic stage to cracking, damage and failure.

[0123] The interface slip curve is used to describe the relative displacement evolution between the cable element and the concrete interface in the concrete model during the loading process, so as to reflect the whole process of interface bond degradation and friction slip.

[0124] The axial force distribution of the reinforcing bars is used to reveal the force transmission of the cable elements along the path in the concrete model, and to determine the force concentration and yield development of the cable elements in different regions of the concrete model.

[0125] The concrete damage factor field is used to reflect the cracking area and failure mode of concrete in the concrete model, thereby simulating the damage propagation process in the concrete model.

[0126] The displacement time history response is used to record the evolution of the displacement of key monitoring points of the concrete model over time or loading step during the entire loading process, in order to evaluate the deformation mode and limit state determination of the structure.

[0127] It is important to emphasize that this invention does not limit the type of numerical solution platform or iterative algorithm; it can be implemented using either the Finite Element Method (FEM) or the Finite Difference Method (FDM). During implementation, the solution platform can employ the Newton-Raphson method, Arc-Length Methods, adaptive step-size strategies, or other nonlinear iterative strategies, depending on different working conditions and computational requirements, to ensure the convergence and stability of the computation. Furthermore, by assigning calibration bond parameters to the cable elements in the concrete model, the system can characterize and provide feedback on the steel-concrete interface slip throughout the numerical simulation.

[0128] Therefore, under any load path and boundary conditions consistent with the engineering scenario, the simulation can maintain consistency in bearing capacity degradation, post-cracking internal force redistribution, and ductile response, and output reliable results that can be used for shield tunnel segment performance evaluation. It should also be noted that this invention does not specify uniform boundary conditions and loading methods; in engineering, they can be set according to actual working conditions. As long as the parameter values ​​are correct, the corresponding working conditions can be accurately reproduced.

[0129] The shield tunnel segment performance evaluation unit 4 is used to perform step S4: calculate and evaluate the indicators of the simulation time history data to obtain the current shield tunnel segment performance evaluation data.

[0130] Specifically, the calculation and evaluation of the indicators are based on the phased division of the interface slip curve in the simulation time history data. The interface behavior is divided into the initial bonding stage, the slip development stage, and the residual friction stage. Each stage is then aligned with other response results in the simulation time history data for evaluation, thereby obtaining a set of performance indicators under different slip stages, i.e., obtaining the current shield tunnel segment performance evaluation data, which specifically includes:

[0131] If the tangent stiffness of the local curve in the interface slip curve is consistent with the shear stiffness in the calibrated bond parameters, and the slip amount does not exceed the critical slip value, the interface is determined to be in the initial bond stage. The corresponding load-displacement curve in the simulation time history data is aligned with the axial force distribution of the reinforcing bars for evaluation. This is used to determine the initial stiffness and stress uniformity of the shield tunnel segment under elastic working state, so as to obtain the evaluation results of the initial bond stage. By default, it includes the initial stiffness coefficient, the uniformity of reinforcing bar stress, and the interface bond integrity rate.

[0132] The critical slip value is determined by the inflection point of the corresponding load slip curve in the calibrated bond parameters before it reaches its peak value.

[0133] When the cohesive strength in the interface slip curve reaches the peak value corresponding to the cohesive strength in the calibrated bond parameters, and the slip amount is within the preset range, the interface is determined to be in the slip development stage. The interface slip curve in the simulation time history data is aligned and evaluated with the concrete damage factor field to characterize the coupling relationship between slip propagation and crack evolution, and the evaluation results of the slip development stage are obtained. By default, these include the maximum slip amount, the proportion of slip section, the crack propagation rate, and the energy dissipation value.

[0134] The preset interval is the range from the critical slip value to the slip amount corresponding to the decrease in cohesive strength of the load-slip curve in the calibrated bond parameters to the residual value.

[0135] When the shear strength in the interface slip curve drops to the residual strength corresponding to the calibrated bond parameters, and the slip exceeds a preset value, the interface is determined to be in the residual friction stage. The peak-to-peak segment of the load-displacement curve in the simulation time history data is aligned with the displacement time history response of key points for evaluation. This is used to identify the structural ultimate bearing capacity and failure mode of the shield tunnel segment, and to obtain the evaluation results of the residual friction stage. By default, these include ultimate bearing capacity, residual bearing capacity, bearing degradation rate, failure segment ratio, and key point displacement exceedance rate.

[0136] The preset value is the amount of slippage corresponding to the decrease in cohesive strength to the residual value of the load-slip curve in the calibration bonding parameters.

[0137] Finally, the evaluation results of the initial bonding stage, the slip development stage, and the residual friction stage are integrated to obtain the performance evaluation data of the tunnel segments.

[0138] It is important to emphasize that this invention aligns the entire process of interface sliding with other mechanical response data from the simulation time history data to achieve the evaluation from local interface behavior to overall performance. Furthermore, by using parameters from the calibrated bonding parameters as evaluation thresholds, the consistency between simulation and experiment is ensured, thereby improving the reliability and accuracy of performance evaluation.

[0139] Furthermore, since the stress state, yield characteristics, and energy dissipation mechanisms of reinforcing bars differ under various engineering conditions, they need to be determined based on the actual situation. Therefore, reinforcing bars can adopt elastic constitutive models, elastoplastic constitutive models, or other equivalent yield models to simulate their stress and yielding processes. However, regardless of the specific reinforcing bar constitutive model used, the core of this invention lies in characterizing the bond-slip effect between the reinforcing bar and concrete through cable elements, thereby realistically reflecting the impact of the entire slip process on the overall mechanical properties. Therefore, this invention only requires that the cable elements can correctly achieve the full process control and feedback of interface slip, without restricting the form of the reinforcing bar constitutive model.

[0140] Compared to existing technologies, this invention uses cable elements instead of the traditional combination of beam and interface elements for modeling, explicitly introducing the bond-slip effect at the steel-concrete interface, thus avoiding the overestimation of stiffness and bearing capacity caused by the assumption of complete bond.

[0141] Please see Figure 3 , Figure 3 This is a schematic diagram comparing the load-displacement curves obtained from the concrete model with slip characteristics constructed in this invention under damage loading conditions with experimental results. Figure 3 As can be seen, the numerical simulation results are highly consistent with the experimental results. In the elastic stage, the curve slope is large, indicating high overall stiffness. As loading continues, the curve slope gradually decreases, damage begins to appear on the inner surface of the segments, and the structure enters the plastic stage. The numerical simulation can accurately reproduce the nonlinear evolution law shown in the experiment, with a load deviation of only 0.76% from the experimental value, verifying the authenticity and effectiveness of the model after introducing the bond-slip effect through the cable element.

[0142] Please see Figure 4 , Figure 4 This is a schematic diagram comparing the load-displacement curves obtained from the concrete model with sliding characteristics constructed in this invention under the ultimate bearing capacity condition of a tunnel segment with those from a full-scale loading experiment. Figure 4As can be seen, in the initial loading stage, the numerical calculation curve of this invention closely matches the experimental curve. When the vertical displacement at mid-span is in the range of 10-20 mm, the simulation result is slightly higher than the experimental value. This is because the actual specimen contains a large number of microcracks that gradually develop, while the numerical simulation only triggers crack formation after the damage accumulates to a certain extent, thus producing a slight difference in this range. However, as the loading continues, the curves regain good consistency. Therefore, by using cable elements and calibrating the bonding parameters, this invention can not only realistically reflect the slip effect of the steel-concrete interface, but also accurately reproduce the entire process of the shield tunnel segment from the elastic stage, the damage stage to the ultimate failure stage at the overall response level, ensuring the reliability of the simulation results.

[0143] Based on the same inventive concept, this application also provides an electronic device, which can be a server, desktop computing device, or mobile computing device (e.g., laptop computing device, handheld computing device, tablet computer, netbook, etc.). The device includes one or more processors and a memory, wherein the processor is used to execute a program to implement the numerical calculation method for simulating the slippage of tunnel segments and internal reinforcing bars according to embodiments of the present invention; the memory is used to store computer programs executable by the processor.

[0144] Based on the same inventive concept, this application also provides a computer-readable storage medium corresponding to the aforementioned embodiment of a numerical calculation method for simulating the slippage of a tunnel segment and its built-in reinforcing bars. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the steps of the numerical calculation method for simulating the slippage of a tunnel segment and its built-in reinforcing bars as described in any of the above embodiments.

[0145] This application may take the form of a computer program product implemented on one or more storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing program code. Computer storage media include permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information may be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to: phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0146] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and the present invention also intends to include these modifications and variations.

Claims

1. A numerical calculation method for simulating slippage between tunnel segments and internal reinforcing bars, characterized in that, Includes the following steps: S1: Mesh the three-dimensional shield tunnel segments according to the reinforcement information to obtain the initial concrete model; S2: Construct cable elements and embed them, along with the calibrated bond parameters, into the initialized concrete model to obtain a concrete model with slip characteristics; S3: Based on the preset load, perform incremental iterations on the concrete model with slip characteristics to obtain simulation time history data; S4: Calculate and evaluate the performance indicators of the simulation time history data to obtain the current performance evaluation data of the tunnel lining segments; The embedding into the initial concrete model includes the following sub-steps: The reinforcement layout path in the initial concrete model is converted into computable cable elements, forming a concrete model containing cable elements. Next, based on the basic physical parameters and calibration bond parameters of the reinforcing bars, values ​​are assigned to the cable elements in the concrete model containing cable elements to form a reinforced concrete model with stress response characteristics. The calibrated bond parameters include cohesive strength, friction angle, shear stiffness, residual cohesive strength, critical slip, and residual initial slip, which are obtained through the following steps: First, based on the single-rib pull-out test, mechanical data sets were collected during the pull-out process to form load-slip curves and stress-strain curves; Meanwhile, based on the initial concrete model, cable elements are introduced and a set of intermediate bond parameters to be optimized are assigned to them. The numerical simulation platform is used to perform incremental iterative calculations on the single-reinforcement pull-out condition to obtain the corresponding simulated load-slip curves. The intermediate binding parameters refer to the set of intermediate parameters that have not yet been fully iterated, and are specifically represented as follows: In the formula, Indicates intermediate bonding parameters; Indicates cohesive strength; Indicates the angle of friction; Indicates shear stiffness; Indicates residual cohesive strength; Indicates critical slip; Indicates residual initiation slip; The incremental iterative calculation refers to gradually applying displacement loads in a numerical simulation platform and solving the response of the steel-concrete interface at each loading step to obtain the simulated load-slip curve. Then, the deviation value of the simulated load-slip curve and the corresponding load-slip curve in the mechanical dataset is calculated using the objective function to obtain the deviation value of the current intermediate bond parameters; Subsequently, it is determined whether the deviation value of the current intermediate bonding parameter meets the iteration threshold: if not, it is considered that the current intermediate bonding parameter has not converged, an optimization algorithm is called to update the current intermediate bonding parameter to obtain the updated intermediate bonding parameter, and incremental iteration calculation continues; if yes, it is considered that the current intermediate bonding parameter has been calibrated and is used as the calibration bonding parameter.

2. The numerical calculation method for simulating the slippage between tunnel segments and internal reinforcing bars according to claim 1, characterized in that, The specific representation of the objective function is as follows: In the formula, Indicates the first Intermediate bonding parameters of the next iteration The corresponding deviation value; Indicates the first Under the intermediate bonding parameters of the second iteration, the end displacement was advanced to the third iteration through numerical simulation. Slip amount corresponding to each sampling point The load obtained from the model reaction force at that time; This indicates that the slip in the mechanics dataset is... At that time, the corresponding load; This represents the normalized reference value, and N represents the total number of sampling points.

3. The numerical calculation method for simulating the slippage between tunnel segments and internal reinforcing bars according to claim 1, characterized in that, The specific representation of the objective function is as follows: In the formula, Indicates the first Intermediate bonding parameters of the next iteration The corresponding deviation value; The objective function for the initial bonding stage is expressed as follows: In the formula, Used to indicate the total number of sampling points in the initial bonding stage; This indicates an indicator function that outputs 1 if the condition is met, and 0 otherwise. Indicates the first The critical slip corresponding to the intermediate bonding parameters of the next iteration; Indicates the first Under the intermediate bonding parameters of the second iteration, the end displacement was advanced to the third iteration through numerical simulation. Slip amount corresponding to each sampling point The load obtained from the model reaction force at that time; The objective function representing the slip development stage is calculated as follows: In the formula, Used to indicate the total number of sampling points in the slip development stage; Indicates the first The residual initiation slip corresponding to the intermediate bonding parameters of the next iteration; This indicates that the slip in the mechanics dataset is... At that time, the corresponding load; Indicates the normalized reference value; The objective function representing the residual friction stage is calculated as follows: In the formula, Used to represent the total number of sampling points in the residual friction stage; Indicates the boundary penalty term; This represents the experimental critical slip directly identified from the load-slip curve of a single-rib pull-out test; The residual initiation slip identified from the load-slip curve of the single-rib pull-out test; and These are dimensionless weighting coefficients.

4. A numerical calculation device for simulating the slippage between tunnel segments and internal reinforcing bars, characterized in that, It includes shield tunnel segment concrete mesh division unit, cable unit embedding unit, load simulation unit and shield tunnel segment performance evaluation unit; The shield tunnel segment concrete mesh division unit is used to divide the three-dimensional shield tunnel segment into meshes according to the reinforcement information to obtain the initial concrete model. The cable unit embedding unit is used to construct cable units and embed them, along with the calibrated bonding parameters, into the initialized concrete model to obtain a concrete model with slip characteristics. The load simulation unit is used to incrementally iterate on a concrete model with slip characteristics according to a preset load to obtain simulation time history data. The shield tunnel segment performance evaluation unit is used to calculate and evaluate the indicators of the simulation time history data to obtain the current shield tunnel segment performance evaluation data. The embedding into the initial concrete model includes the following sub-steps: The reinforcement layout path in the initial concrete model is converted into computable cable elements, forming a concrete model containing cable elements. Next, based on the basic physical parameters and calibration bond parameters of the reinforcing bars, values ​​are assigned to the cable elements in the concrete model containing cable elements to form a reinforced concrete model with stress response characteristics. The calibrated bond parameters include cohesive strength, friction angle, shear stiffness, residual cohesive strength, critical slip, and residual initial slip, which are obtained through the following steps: First, based on the single-rib pull-out test, mechanical data sets were collected during the pull-out process to form load-slip curves and stress-strain curves; Meanwhile, based on the initial concrete model, cable elements are introduced and a set of intermediate bond parameters to be optimized are assigned to them. The numerical simulation platform is used to perform incremental iterative calculations on the single-reinforcement pull-out condition to obtain the corresponding simulated load-slip curves. The intermediate binding parameters refer to the set of intermediate parameters that have not yet been fully iterated, and are specifically represented as follows: In the formula, Indicates intermediate bonding parameters; Indicates cohesive strength; Indicates the angle of friction; Indicates shear stiffness; Indicates residual cohesive strength; Indicates critical slip; Indicates residual initiation slip; The incremental iterative calculation refers to gradually applying displacement loads in a numerical simulation platform and solving the response of the steel-concrete interface at each loading step to obtain the simulated load-slip curve. Then, the deviation value of the simulated load-slip curve and the corresponding load-slip curve in the mechanical dataset is calculated using the objective function to obtain the deviation value of the current intermediate bond parameters; Subsequently, it is determined whether the deviation value of the current intermediate bonding parameter meets the iteration threshold: if not, it is considered that the current intermediate bonding parameter has not converged, an optimization algorithm is called to update the current intermediate bonding parameter to obtain the updated intermediate bonding parameter, and incremental iteration calculation continues; if yes, it is considered that the current intermediate bonding parameter has been calibrated and is used as the calibration bonding parameter.

5. The numerical calculation device for simulating the slippage between tunnel segments and internal reinforcing bars according to claim 4, characterized in that, The specific representation of the objective function is as follows: In the formula, Indicates the first Intermediate bonding parameters of the next iteration The corresponding deviation value; Indicates the first Under the intermediate bonding parameters of the second iteration, the end displacement was advanced to the third iteration through numerical simulation. Slip amount corresponding to each sampling point The load obtained from the model reaction force at that time; This indicates that the slip in the mechanics dataset is... At that time, the corresponding load; This represents the normalized reference value, and N represents the total number of sampling points.

6. The numerical calculation device for simulating the slippage between tunnel segments and internal reinforcing bars according to claim 4, characterized in that, The specific representation of the objective function is as follows: In the formula, Indicates the first Intermediate bonding parameters of the next iteration The corresponding deviation value; The objective function for the initial bonding stage is expressed as follows: In the formula, Used to indicate the total number of sampling points in the initial bonding stage; This indicates an indicator function that outputs 1 if the condition is met, and 0 otherwise. Indicates the first The critical slip corresponding to the intermediate bonding parameters of the next iteration; Indicates the first Under the intermediate bonding parameters of the second iteration, the end displacement was advanced to the third iteration through numerical simulation. Slip amount corresponding to each sampling point The load obtained from the model reaction force at that time; The objective function representing the slip development stage is calculated as follows: In the formula, Used to indicate the total number of sampling points in the slip development stage; Indicates the first The residual initiation slip corresponding to the intermediate bonding parameters of the next iteration; This indicates that the slip in the mechanics dataset is... At that time, the corresponding load; Indicates the normalized reference value; The objective function representing the residual friction stage is calculated as follows: In the formula, Used to represent the total number of sampling points in the residual friction stage; Indicates the boundary penalty term; This represents the experimental critical slip directly identified from the load-slip curve of a single-rib pull-out test; The residual initiation slip identified from the load-slip curve of the single-rib pull-out test; and These are dimensionless weighting coefficients.

7. An electronic device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, when the processor executes the computer program, it implements a numerical calculation method for simulating the slippage of tunnel segments and built-in reinforcing bars as described in any one of claims 1-3.

8. A computer-readable storage medium storing computer-executable instructions, characterized in that, When the computer-executable instructions are executed by the processor, they implement a numerical calculation method for simulating the slippage of tunnel segments and built-in reinforcing bars as described in any one of claims 1-3.

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