Method, medium and device for constructing feature irregularities based on damage evolution model

Abstract

This invention relates to the field of track bridge engineering technology, and particularly to a method, medium, and equipment for constructing characteristic irregularities based on a damage evolution model. The method includes: establishing a track damage evolution model based on a simplified track structure model and an adaptive grid evolution mechanism; constructing characteristic residual irregularities based on the track damage evolution model under different load steps and different pier settlement amplitudes, including: selecting different pier settlement amplitudes based on the damage evolution model corresponding to different load steps and performing coupled analysis with two working conditions: design earthquake and rare earthquake, to calculate the track residual irregularities; constructing characteristic residual irregularities based on the statistical characteristics of the track residual irregularities using wavelet packet transform, which compensates for the deficiencies of short-time Fourier transform and wavelet transform in terms of time-frequency resolution, and the damage evolution model can identify the location of inter-layer damage and shorten the calculation time.

Description

Technical Field

[0001] This invention relates to the field of railway bridge engineering technology, and in particular to a method, medium and equipment for constructing characteristic irregularities based on a damage evolution model. Background Technology

[0002] As a crucial component of the modern transportation system, the operational safety and transportation efficiency of high-speed trains are directly determined by the service safety and structural stability of their track-bridge systems. However, with the increasing density and scale of the global high-speed rail network, high-speed rail lines inevitably approach or even cross seismically active zones and subsidence-sensitive areas, posing a severe challenge to the operational safety and passenger comfort of high-speed trains when crossing bridges.

[0003] With the popularization of computer technology, machine learning has gradually become a popular technique for predicting structural response and assessing earthquake damage. Existing technologies have established a rapid assessment framework for post-earthquake track damage based on GNNs and genetic algorithms, enabling rapid prediction of damage status of regional railway lines. In addition, a novel recurrent neural network based on PKRNN has been proposed, which effectively and efficiently predicts the structural response of bridges under seismic loads. Furthermore, a neural network model based on Bi-LSTM and VHXLA has been proposed, which can accurately predict the structural response and seismic damage status of high-speed railway track-bridge systems.

[0004] Because track-bridge systems in settlement-sensitive zones are highly susceptible to pier settlement defects, which seriously jeopardize the safe and stable operation of trains, existing technologies have also disclosed a characterization model based on Castigliano's Second Theorem that establishes the relationship between pier settlement and track interlayer interface failure. This model analyzes the development law of track interlayer interface failure and shows that mortar damage caused by pier settlement is not easily observed. For longitudinally connected slab track, special attention should be paid to the gap between the bottom of the base slab and the bridge deck.

[0005] However, there is a complex coupling effect between seismic loads and bridge pier settlement. On the one hand, bridge pier settlement alters the initial state and boundary conditions of the structure, affecting its stiffness and mass distribution, and consequently changing its dynamic characteristics, such as natural frequencies and mode shapes. This directly impacts the structure's dynamic response characteristics under seismic loading. On the other hand, the additional stress caused by settlement superimposed on the stress generated by the seismic dynamic response reduces the structure's seismic resistance and safety reserve, leading to stress exceeding limits in critical structural components and accelerating structural damage accumulation. Therefore, to assess the adverse effects of the coupling effect of seismic load and pier settlement on the safe operation of high-speed railways, the following research limitations need to be addressed: (1) Existing studies mostly consider seismic load and pier settlement as independent factors, lacking in-depth discussion on the coupling mechanism between the two; (2) There is a lack of computational models that can effectively simulate the coupling effect of seismic load and pier settlement; (3) There are few reports on the evolution mechanism and evolution law of interlayer damage of CRTS III type slab track, ignoring the influence of interlayer damage on track residual irregularities; (4) There is a lack of effective quantitative research on the aggravation effect of pier settlement on post-earthquake track residual irregularities.

[0006] Therefore, it is necessary to provide a new method, medium, and device for constructing characteristic irregularities based on a damage evolution model to solve the above-mentioned technical problems. Summary of the Invention

[0007] The main objective of this invention is to provide a characteristic irregularity construction method, medium, and device based on a damage evolution model, which aims to solve the problem that existing methods cannot effectively simulate the coupling effect of seismic loads and bridge pier settlement.

[0008] To achieve the above objectives, this invention proposes a method for constructing feature irregularities based on a damage evolution model, comprising the following steps: S1: Select a beam bridge system as the research object; S2: Establish an orbital damage evolution model based on a simplified orbital structure model and an adaptive grid evolution mechanism for the research object; S3: Characteristic residual irregularities are constructed based on track damage evolution models under different load steps and different pier settlement amplitudes; S3 includes: S3.1 Based on the track damage evolution model corresponding to different load steps, different pier settlement amplitudes are selected and coupled with two working conditions, design earthquake and rare earthquake, respectively, to calculate the track residual irregularity; S3.2. Based on the statistical characteristics of track residual irregularities, wavelet packet transform is used to construct characteristic residual irregularities.

[0009] Optionally, S2 includes: S2.1. Model the research object to obtain a traditional track structure model; S2.2. The track slab and self-compacting concrete, which are effectively connected by U-shaped steel bars and pre-embedded steel bars in the traditional track structure model, as well as the base plate and box girder, are regarded as two composite structural systems that satisfy the assumption of interface displacement continuity and stress transfer coordination conditions, respectively, to obtain a simplified track structure model. S2.3 Introducing an adaptive mesh evolution mechanism, by detecting the stress state of the springs between the self-compacting concrete and the base plate, identifying the decoupled areas and performing adaptive mesh refinement, an optimized track structure model is obtained; S2.4. Based on the track structure optimization model, the characteristics of each component of the research object are simulated, and the constitutive relationship of each component is obtained through experiments and field tests to obtain the track damage evolution model.

[0010] Optionally, in S2.1, when modeling the research object, it is assumed that each component of the research object satisfies the following conditions: The steel reinforcement and concrete deform in coordination, the anchorage length meets the design requirements, and the steel reinforcement slippage effect is ignored. Ignoring microcracks and local inhomogeneities in concrete, a homogenized continuous medium model is used to model the concrete. The interlayer shear stress between the track slab and the self-compacting concrete, and between the base plate and the box girder, shall not exceed the bond strength limit to ensure interlayer continuity.

[0011] Optionally, S2.3 includes: S2.3.1 Initialize disconnection status indicators Disconnection length and the number of disconnect springs ; S2.3.2 Setting the number of load steps And set the initial grid size. and initial spring stiffness ; S2.3.3. Perform load step operations on the simplified model of the track structure according to the set load sequence. After the current load step calculation is completed, cyclically check the stress state of each interlayer spring between the self-compacting concrete and the base plate, and determine the interlayer decoupling state based on the spring force of the interlayer spring. Specifically, when the spring force is greater than 0, the decoupling state index corresponding to that interlayer spring is... When the spring force is 0, the interlayer spring is in a disengaged state, proceeding to S2.3.4; when the spring force is 0, the disengagement state index... If the value is 1, the system is not in a state of interlayer disconnection and proceeds to S2.3.5. S2.3.4 Calculate the decoupling length of the decoupling region based on the decoupling state index of the interlayer spring and the element length, and refine the corresponding mesh region locally according to the coordinate information of the interlayer spring and the decoupling length. S2.3.5, Order ,judge If the load step count exceeds the set total load step count, proceed to S2.3.6 and output the structural response, decoupled region distribution, and refined track structure optimization model under each load step; otherwise, return to S2.3.3.

[0012] Optionally, in S2.3.4, the specific formula for calculating the disconnection length is as follows: ; in: This is the length of the disconnection; This refers to the number of continuously disengaged springs; The unit length; This refers to the numbering of the interlayer springs; The specific formula for local mesh refinement is as follows: ; in: and The spring stiffness is for coarse and fine mesh grids, respectively. and These are the cell lengths for the coarse and fine meshes, respectively.

[0013] Optionally, the composite structural system consisting of the track slab and self-compacting concrete can be regarded as a composite slab, and the composite structural system consisting of the base plate and the box girder can be regarded as a composite beam. In S2.4, three-dimensional beam elements are used to simulate the rails, composite plates, composite beams, and piers of the research object. Elastic custom sections are used to characterize the geometric features of the rails, composite plates, and composite beams, and generalized sections are used to simulate the nonlinear plastic behavior of the piers. The abutments of the research object are simplified to a rigid domain, and spring damper elements are set at the bottom of the pile foundation of the research object to simulate the pile-soil interaction at the bottom of the abutments, roadbed, and piers. Combined spring elements are used to simulate the elastic cushion layer and supports. Nonlinear spring elements are used to simulate fasteners and isolation layers, and unidirectional constraint springs are set through the nonlinear constitutive definition function of the nonlinear spring elements. A 20m long roadbed section along the line direction is taken as the model boundary, and fixed constraints are applied to the two ends of the roadbed section.

[0014] Optionally, S3.2 includes: S3.2.1 Perform wavelet packet transform on the residual irregularities of the track to obtain the wavelet packet coefficient matrix. ; S3.2.2 Perform a logarithmic transformation on the wavelet packet coefficient matrix to construct the logarithmic set. And define the kurtosis coefficient of random samples in the logarithmic set. Skewing coefficient ; S3.2.3, Based on kurtosis coefficient Skewing coefficient Define statistical functions and discriminant function ; S3.2.4, when When the value equals 0, assuming the population D corresponding to the random sample follows a normal distribution, then we define an upper bound. The specific quantiles in the normal population D are as follows: ; in: A 1 and A 2 represents the first-order and second-order sample intervals, i.e., the sample mean and sample variance, respectively; Represents the one-sided quantiles of the standard normal distribution; S3.2.5, Take the significance level The value is 0.05, based on the statistical upper bound determined in step S3.2.4. Wavelet packet coefficients that meet the preset normality test conditions are selected, and feature residual irregularities are reconstructed using the wavelet packet reconstruction algorithm.

[0015] Optionally, in S3.2.1, the specific formula for the wavelet packet coefficients of each layer is as follows: ; in: This represents the coefficients of the 0th node at the 0th level of the wavelet packet decomposition, i.e., the residual irregularities of the original trajectory; The track remains uneven. i Number the earthquake motion; j This indicates the number of layers in the wavelet packet decomposition. , J Indicates the maximum number of floors; , Indicates the first j Layer Wavelet packet coefficients of each node; and They represent Low-frequency and high-frequency components; and g These represent high-pass and low-pass filters, respectively. Indicates the coefficient index of the filter; These are discrete coordinates used to locate the coefficients of each layer after wavelet decomposition. In S3.2.1, the wavelet packet coefficient matrix The specific expression is as follows: ; in: NThis represents the total number of columns in the wavelet packet coefficient matrix; In S3.2.2, the kurtosis coefficient of the random sample Skewing coefficient The specific formula is as follows: ; ; in: For random samples, For sample size; It is a natural number index variable used to represent the sample number. Take 1 to 0 natural numbers; Represents the mean of a random sample; In S3.2.3, the statistical function and discriminant function The specific formula is as follows: ; ; in: For chi-square distribution Quantiles The significance level; In S3.2.5, the specific formula for the wavelet packet reconstruction algorithm is as follows: ; in: H and G These represent the low-pass and high-pass filters used in wavelet packet reconstruction, respectively.

[0016] In addition, the present invention provides a readable storage medium storing computer program instructions that, when executed by a processor, implement the feature irregularity construction method based on the damage evolution model as described above.

[0017] The present invention also provides an electronic device, comprising: at least one processor, at least one memory, and computer program instructions stored in the memory, wherein the computer program instructions are executed by the processor to construct the feature irregularity based on the damage evolution model as described above.

[0018] The damage evolution model of this invention can effectively identify the location of interlayer damage during mechanical analysis and realize adaptive mesh evolution. Moreover, the simplified design method adopted by the model can shorten the calculation time by about 40% while ensuring the calculation accuracy. The track feature residual irregularity construction method based on wavelet packet transform makes up for the defects of short-time Fourier transform and wavelet transform in terms of time and frequency resolution. The constructed feature residual irregularity has a reasonable safety threshold and can be used as an irregularity excitation input for post-earthquake driving performance analysis of high-speed railway track-bridge system. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the feature irregularity construction method based on the damage evolution model in an embodiment of the present invention. Figure 2(a) is a schematic diagram of the traditional track structure model; Figure 2(b) is a partial structural diagram of Figure 2(a); Figure 3 This is a schematic diagram comparing the traditional track structure model with the simplified track structure model in the embodiment of the present invention; Figure 4(a) is a schematic diagram of the evolution of the adaptive grid evolution mechanism in an embodiment of the present invention; Figure 4(b) is a schematic diagram of the local mesh refinement of Figure 4(a), where the left side represents a settlement of 10 mm and the right side represents a settlement of 20 mm; Figure 5 This is a schematic diagram of the track damage evolution model in an embodiment of the present invention; Figure 6(a) is a schematic diagram of the time-domain results of the simulation and experimental measurement of the track damage evolution model in the embodiment of the present invention; Figure 6(b) is a schematic diagram of the frequency domain results of the simulation and experimental measurement of the track damage evolution model in the embodiment of the present invention; Figure 7(a) is a schematic diagram of the simulation and numerical model results of the track damage evolution model when a single pier settlement load of 5 mm is applied in the embodiment of the present invention; Figure 7(b) is a schematic diagram of the frequency domain results of the simulation and numerical models of the track damage evolution model when a single pier settlement load of 20 mm is applied in an embodiment of the present invention. Figure 8(a) is a schematic diagram showing the comparison results of the track residual irregularities of the traditional track structure model, the simplified track structure model, and the track damage evolution model when the PGA is 0.3g in the embodiment of the present invention. Figure 8(b) is a schematic diagram showing the comparison results of the track residual irregularities of the traditional track structure model, the simplified track structure model, and the track damage evolution model when the PGA is 0.57g in the embodiment of the present invention. Figure 9(a) is a schematic diagram of the ground motion selected according to the design response spectrum in an embodiment of the present invention; Figure 9(b) is a schematic diagram of the ground motion after amplitude modulation processing of the original ground motion data in an embodiment of the present invention; Figure 10 This is a diagram illustrating the mechanism of inter-story damage under pier settlement and seismic loading in an embodiment of the present invention. Figure 11(a) is a schematic diagram of the development law of interlayer damage length between self-compacting concrete and base plate under pier settlement and seismic action in an embodiment of the present invention. Figure 11(b) is a schematic diagram showing the development law of the interlayer damage height between the self-compacting concrete and the base plate under the action of pier settlement and seismic action in the embodiment of the present invention. Figure 12(a) is a schematic diagram of the residual track irregularities under different ground motion conditions considering only the seismic load when the PGA is 0.3g in an embodiment of the present invention; Figure 12(b) is a schematic diagram of the residual track irregularities under different ground motion conditions considering only the seismic load when the PGA is 0.57g in the embodiment of the present invention. Figure 13(a) is a schematic diagram of the residual track irregularities when a 5mm bridge settlement amplitude and a 0.3g seismic load are coupled in an embodiment of the present invention. Figure 13(b) is a schematic diagram of the residual track irregularities when a 10mm bridge settlement amplitude and a 0.3g seismic load are coupled in an embodiment of the present invention. Figure 13(c) is a schematic diagram of the residual track irregularities when a 15mm bridge settlement amplitude and a 0.3g seismic load are coupled in an embodiment of the present invention. Figure 13(d) is a schematic diagram of the residual track irregularities when a 20mm bridge settlement amplitude and a 0.3g seismic load are coupled in an embodiment of the present invention. Figure 14(a) is a schematic diagram of the residual track irregularities when a 5mm bridge settlement amplitude and a 0.57g seismic load are coupled in an embodiment of the present invention. Figure 14(b) is a schematic diagram of the residual track irregularity when a 10mm bridge settlement amplitude and a 0.57g seismic load are coupled in an embodiment of the present invention. Figure 14(c) is a schematic diagram of the residual track irregularity when a 15mm bridge settlement amplitude and a 0.57g seismic load are coupled in an embodiment of the present invention. Figure 14(d) is a schematic diagram of the residual track irregularities when a 20mm bridge settlement amplitude and a 0.57g seismic load are coupled in an embodiment of the present invention. Figure 15(a) is a schematic diagram of the characteristic residual irregularities when PGA is 0.3g in an embodiment of the present invention; Figure 15(b) is a schematic diagram of the characteristic residual irregularities when PGA is 0.57g in an embodiment of the present invention; Figure 16(a) is a schematic diagram verifying the rationality of the residual irregularity of features when PGA is 0.3g in an embodiment of the present invention; Figure 16(b) is a schematic diagram for verifying the rationality of the residual irregularity of features when PGA is 0.57g in an embodiment of the present invention; Figure 17(a) is a schematic diagram of the applicability verification of the feature residual irregularity when PGA is 0.3g in an embodiment of the present invention; Figure 17(b) is a schematic diagram of the applicability verification of the feature residual irregularity when PGA is 0.57g in an embodiment of the present invention.

[0021] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

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

[0023] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0024] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0027] This invention proposes a characteristic irregularity construction method, medium, and equipment based on a damage evolution model, aiming to solve the problem that existing methods cannot effectively simulate the coupling effect of seismic loads and bridge pier settlement.

[0028] See Figure 1 This embodiment provides a method for constructing feature irregularities based on a damage evolution model, including the following steps: S1: Select a beam bridge system as the research object; This embodiment takes the CRTS III type slab track-simply supported beam bridge system with 5 spans and 14m pier height as the research object; S2: Establish an orbital damage evolution model based on a simplified orbital structure model and an adaptive grid evolution mechanism for the research object; S2 includes: S2.1. Model the research object to obtain a traditional track structure model; Referring to Figures 2(a) and 2(b), the CRTS III type slab track system (i.e., the traditional track structure model) on the bridge mainly consists of seven parts, from top to bottom: rails, fasteners, track slabs, self-compacting concrete layer, isolation layer, elastic pad layer, and base plate. The rails are 60 kg / m, U71MnG, 100 m long boltless new rails. The fasteners are WJ-8 type, with a fastener spacing of 630 mm within the track slab and 620 mm between fasteners at the ends of adjacent track slabs. The track slabs are factory-prefabricated bidirectional prestressed concrete structures with embedded U-shaped steel bars at the bottom. Their core function is to achieve precise rail positioning through pre-set rail grooves and a matching fastener system, thereby maintaining the geometric stability of the track. The base plate is made of C40 concrete and cast on-site on the bridge deck, corresponding one-to-one with the track slabs in a unit structure, and is tightly connected to the box girder by 26 embedded steel bars. A 0.004m thick isolation layer (geotextile) is laid on the upper surface of the base plate to release interlayer temperature differences and shrinkage stress. Two limiting grooves are set on each base plate. An elastic pad is adhered to the sidewalls of the grooves with adhesive, and the joints are sealed with tape to meet structural stress, deformation, and material durability requirements. To fix the fine-tuning results of the track slab and bond it to the base plate, a 90mm thick self-compacting concrete structural layer with a strength grade of C40 is filled between the track slab and the base plate. Its length and width are the same as the track slab. Crack-resistant steel mesh is designed within the structural layer, connected and fixed to the reinforcement in the limiting grooves of the base plate. During the pouring process, it forms a boss with the grooves of the base plate to achieve horizontal limiting. Traditional modeling methods, to accurately simulate the mechanical response of the track-bridge coupled system, fully consider the key components of each track section and establish a three-dimensional refined finite element model. However, this modeling strategy has the following limitations: (i) it fails to simplify the model according to the characteristics of the track structure, which affects the overall computational efficiency; (ii) contact nonlinearity problems lead to difficulties in model convergence; (iii) the selection of interlayer connection unit types for track slab-self-compacting concrete and base plate-box girder is unreasonable, which affects the overall computational accuracy.

[0029] In S2.1, when modeling the research object, it is assumed that each component of the research object satisfies the following conditions: The steel reinforcement and concrete deform in coordination, the anchorage length meets the design requirements, and the steel reinforcement slippage effect is ignored. Ignoring microcracks and local inhomogeneities in concrete, a homogenized continuous medium model is used to model the concrete. The interlayer shear stress between the track slab and the self-compacting concrete, and between the base plate and the box girder, shall not exceed the bond strength limit to ensure interlayer continuity.

[0030] S2.2. The track slab and self-compacting concrete, effectively connected by U-shaped steel bars and embedded steel bars in the traditional track structure model, as well as the base plate and box girder, are respectively considered as two composite structural systems satisfying the assumption of interface displacement continuity and stress transfer compatibility conditions, resulting in a simplified track structure model. A comparison diagram between the simplified track structure model and the traditional track structure model can be found in [reference needed]. Figure 3 While ensuring the geometric characteristics of the track structure remain unchanged, by equating the track slab and self-compacting concrete to composite slabs, and the base plate and box girder to composite beams, the number of nodes and elements in the finite element model is reduced by approximately 33.3% and 40%, respectively, significantly improving computational efficiency. Simultaneously, the composite structure directly couples the inter-story displacement coordination relationship, avoiding the convergence problem of nonlinear contact algorithms and eliminating the lateral slip error generated when using multi-point constrained elements to simulate inter-story connections in traditional models, thus improving the accuracy of structural response calculations.

[0031] In this embodiment, the equivalent elastic modulus of the composite structure system It can be expressed as follows: ; In the formula, and These represent the elastic models of the upper and lower track structures in the composite structure, respectively. and These represent the cross-sectional areas of the upper and lower track structures in the composite structure, respectively.

[0032] Furthermore, based on the equilibrium condition of the first moment of the cross section, the position of the equivalent neutral axis is... It can be expressed as follows: ; In the formula, and These represent the positions of the neutral axes of the upper and lower track structures in the composite structure, respectively. S2.3 Introducing an adaptive mesh evolution mechanism, by detecting the stress state of the springs between the self-compacting concrete and the base plate, identifying the decoupled areas and performing adaptive mesh refinement, an optimized track structure model is obtained; Referring to Figures 4(a) and 4(b), the adaptive mesh evolution mechanism in this embodiment detects the stress state of the springs between the self-compacting concrete and the base plate, identifies the decoupled regions, and performs adaptive mesh refinement to achieve accurate calculation of the decoupled regions. This mechanism combines two scales: coarse fastener spacing mesh and locally refined mesh. After the current load step calculation is completed, the stress state of the springs between the self-compacting concrete and the base plate is cyclically detected, and the coordinate information of the failed springs is stored. In the next load step calculation, the failed region is locally refined based on the coordinate information, and the model contact relationship is updated and the solution is recalculated.

[0033] S2.3 includes: S2.3.1 Initialize disconnection status indicators Disconnection length and the number of disconnect springs ; S2.3.2 Setting the number of load steps And set the initial grid size. and initial spring stiffness ; S2.3.3. Perform load step operations on the simplified model of the track structure according to the set load sequence. After the current load step calculation is completed, cyclically check the stress state of each interlayer spring between the self-compacting concrete and the base plate, and determine the interlayer decoupling state based on the spring force of the interlayer spring. Specifically, when the spring force is greater than 0, the decoupling state index corresponding to that interlayer spring is... When the spring force is 0, the interlayer spring is in a disengaged state, proceeding to S2.3.4; when the spring force is 0, the disengagement state index... If the value is 1, it is not in the interlayer decoupling state, and proceeds to S2.3.5; In this embodiment, based on the connection characteristics between self-compacting concrete and base plate, a unidirectional compression spring is used to simulate the vertical mechanical behavior of the contact interface between the two. When interlayer decoupling occurs, the interlayer spring fails and the spring force is 0. Based on this characteristic, the interlayer decoupling state is judged.

[0034] S2.3.4 Calculate the decoupling length of the decoupling region based on the decoupling state index of the interlayer spring and the element length, and refine the corresponding mesh region locally according to the coordinate information of the interlayer spring and the decoupling length. In S2.3.4, the specific formula for calculating the disconnection length is as follows: ; in: This is the length of the disconnection; This refers to the number of continuously disengaged springs; The unit length; This refers to the numbering of the interlayer springs; The specific formula for local mesh refinement is as follows: ; in: and The spring stiffness is for coarse and fine mesh grids, respectively. and These are the cell lengths for the coarse and fine meshes, respectively. In this embodiment, the initial cell length is 0.63m.

[0035] S2.3.5, Order ,judge If the load step count exceeds the set total load step count, proceed to S2.3.6 and output the structural response, decoupled region distribution, and refined track structure optimization model under each load step; otherwise, return to S2.3.3.

[0036] The track-bridge system was initially modeled using a coarse fastener spacing grid. As pier settlement and seismic loads were gradually applied, interlayer decoupling regions emerged on both sides of the beam joints. Based on a pre-defined grid transformation criterion, local grid refinement was implemented in these critical areas, effectively realizing an adaptive evolution mechanism for the computational grid and ensuring a balance between numerical solution accuracy and computational efficiency.

[0037] S2.4. Based on the track structure optimization model, the characteristics of each component of the research object are simulated, and the constitutive relationship of each component is obtained through experiments and field tests to obtain the track damage evolution model.

[0038] See Figure 5 The damage evolution model was developed based on an existing software platform. Rails, composite plates, composite beams, and piers were simulated using a quadratic three-node beam element in 3-D (BEAM189). The first three types of structures were characterized by elastic custom sections. The pier structure was simulated using a generalized section to represent its nonlinear plastic behavior. The abutments were simplified to rigid domains in the finite element model. The pile-soil interaction between the abutments, subgrade, and pier bases was simulated by placing spring-damper elements (COMBIN14) at the bottom of the pile foundations, with the spring stiffness determined based on the ground reaction modulus method. According to Saint Venant's Principle, a 20m subgrade section was selected to eliminate the influence of boundary effects, and fixed constraints were applied to both sides of the model. Rayleigh damping was used for dynamic calculations, with a damping ratio of 0.05.

[0039] Considering the gap effect of the elastic pad and the slip characteristics of the support, a combined spring element (COMBIN40) is used for simulation. The fasteners and isolation layer are simulated using a nonlinear spring element (COMBIN39). To address the mechanical characteristics of the isolation layer, which is subjected to compression only and not tension in the vertical direction, a unidirectional constraint spring is set using the nonlinear constitutive definition function of the COMBIN39 element. This spring provides effective stiffness during compression and reduces its stiffness to zero during tension to simulate contact separation.

[0040] In this embodiment, the composite structural system composed of the track slab and self-compacting concrete is regarded as a composite slab, and the composite structural system composed of the base plate and the box girder is regarded as a composite beam. In S2.4, three-dimensional beam elements are used to simulate the rails, composite plates, composite beams, and piers of the research object. Elastic custom sections are used to characterize the geometric features of the rails, composite plates, and composite beams, and generalized sections are used to simulate the nonlinear plastic behavior of the piers. The abutments of the research object are simplified to a rigid domain, and spring damper elements are set at the bottom of the pile foundation of the research object to simulate the pile-soil interaction at the bottom of the abutments, roadbed, and piers. Combined spring elements are used to simulate the elastic cushion layer and supports. Nonlinear spring elements are used to simulate fasteners and isolation layers, and unidirectional constraint springs are set through the nonlinear constitutive definition function of the nonlinear spring elements. A 20m long roadbed section along the line direction is taken as the model boundary, and fixed constraints are applied to the two ends of the roadbed section.

[0041] In this embodiment, a seismic testing platform in the laboratory is used to verify the seismic operation conditions. The testing platform consists of six parts: a shaking table system, a train system, a track-bridge system, an acceleration device system, a deceleration device system, and a testing device system. The track-bridge system adopts a scaled-down model with a geometric scale of 1:10. Considering that the finite element model does not include the train part, a simplified scheme is adopted for the verification test: the connecting rails are disconnected, and seismic excitation is directly applied to the track-bridge system through the shaking table system, and its seismic response data is recorded.

[0042] Since the track-bridge system in the test platform did not have subgrade boundary conditions, the subgrade boundary of the damage evolution model was removed during model verification, and only the target structure was retained for analysis. The seismic excitation applied in the test was used as the seismic input condition for the damage evolution model, and nonlinear time history analysis was conducted to extract the numerical simulation results calculated by the damage evolution model. The numerical simulation results were multiplied by the corresponding similarity coefficient and compared with the experimental measured data. The acceleration time history at the mid-span of a box girder specimen was used as a comparison index, and the comparison results are shown in Figures 6(a) and 6(b). Figure 6(a) shows that in the time domain results, the peak value of the experimental acceleration at the mid-span of box girder specimen No. 5 is 0.22g, while the calculated value based on the damage evolution model is 0.20g, with a relative error of 9.09%. Figure 6(b) shows that in the frequency domain results, the peak value of the amplitude spectrum of the experimental results is 0.0209, while the corresponding calculated value of the damage evolution model is 0.0264, with a relative error of 26.32%. Overall, the numerical simulation results of the damage evolution model have a high degree of overlap with the experimental data, and the curve shapes and trends are basically consistent, which verifies the accuracy and reliability of the damage evolution model under seismic conditions.

[0043] The numerical model established using existing technology was used to verify the bridge pier settlement condition. Based on the parameter configuration of the numerical model, the key structural parameters of the damage evolution model were set. Then, single-pier settlement loads of 5mm and 20mm were applied to the model, and the vertical displacement of the rails was calculated and extracted. The calculation results of the damage evolution model were compared with the results of the numerical model. The comparison results are shown in Figures 7(a) and 7(b). It can be seen that the rail displacement curves of the damage evolution model and the numerical model are in good agreement, with the curve difference not exceeding 0.1mm, verifying the correctness and applicability of the damage evolution model under the bridge pier settlement condition.

[0044] This embodiment quantitatively evaluates the effectiveness of the simplified design and adaptive mesh evolution mechanism for track structure modeling. The same seismic load and pier settlement load were applied to the traditional model, the simplified design, and the damage evolution model, respectively. The comparison results of the residual track irregularity curves, computation time, and interlayer gap length for the three models are shown in Table 1 and Figures 8(a) and 8(b). The curve labels in Table 1 correspond to the curves in Figure 8.

[0045] Table 1 Comparison of computational performance of different computational models

[0046] From Table 1 and Figures 8(a) and 8(b), we can see that: (1) Simplifying the design of the traditional model can reduce the model calculation time by about 40%, and at the same time eliminate the lateral slip error (the main reason for the deviation of the uneven curve) generated when using multi-point constraint elements to simulate the interlayer connection between the track slab and self-compacting, the base plate and the box girder in the traditional model.

[0047] (2) Although the damage evolution model adopts the simplified design of trajectory modeling, the finite element mesh refinement caused by the adaptive mesh evolution mechanism increases the model calculation time by about 5%.

[0048] (3) From the perspective of interlayer damage length, the simplified design has no significant impact on the void length caused by pier settlement, while the interlayer damage length of the damage evolution model is significantly reduced, which fully demonstrates the effectiveness of the adaptive grid evolution mechanism.

[0049] (4) The trajectory irregularity curves of the damage evolution model are significantly different from those of the other two models, indicating that the interlayer damage area has a significant impact on the post-earthquake residual irregularity, highlighting the necessity of the adaptive grid evolution mechanism.

[0050] S3: Characteristic residual irregularities are constructed based on track damage evolution models under different load steps and different pier settlement amplitudes; This embodiment simulates the actual stress scenario of a track-bridge system in a settlement-sensitive area under seismic loading, coupling pier settlement and seismic load onto the damage evolution model established in this embodiment. The two load application methods are as follows: (1) Pier settlement Bridge pier settlement is a typical displacement-type static load, and its core input lies in simulating the forced structural displacement and secondary internal forces caused by bridge pier settlement. In the damage evolution model, the bridge pier settlement load is applied in the form of forced nodal displacement. The foundation node at the bottom of the settlement pier is selected as the loading object, and a preset vertical (Z-axis direction) settlement displacement value is applied, while the original displacement constraints are maintained in other directions (horizontal X and Y axes).

[0051] (2) Seismic load Seismic load is a dynamic load, and its core input lies in the reasonable selection of seismic motion input parameters and loading methods. In this embodiment, the site fortification intensity is selected as level 2 of 8 degrees, the site category is Class II, and the characteristic period zone is Zone 1, generating the design response spectrum under the design earthquake, as shown in Figure 9(a). The characteristic period of the design response spectrum is 0.35s, and the peak ground acceleration is 0.675g. The design response spectrum is imported into the NGA-West2 seismic motion database (https: / / ngawest2.berkeley.edu / ), and the 40 seismic motions with the highest matching degree are selected and applied to the damage evolution model through the uniform acceleration excitation method. Since the track is unlikely to generate damage and residual displacement under frequent earthquakes, this embodiment selects peak ground acceleration of two types, design earthquake and rare earthquake, as the analysis conditions. After amplitude modulation processing of the original seismic motion data, a 10-second zero value segment is added to the end of the acceleration time history curve to simulate the free vibration process of the structure after the earthquake, as shown in Figure 9(b). Under the constraints of the roadbeds on both sides, the track-bridge system has a large resistance to deformation in the longitudinal direction (X-axis direction). Therefore, this embodiment ignores the influence of longitudinal seismic loads and focuses on the effects of transverse (Y-axis direction) and vertical (Z-axis direction) seismic loads.

[0052] Based on the laying method of the CRTS III type slab track on the bridge, it is known that when the bridge piers settle, the adjacent spans of the beams will experience vertical displacement under their own weight and the load of the superstructure, and this displacement will be projected upwards, causing corresponding deformation of the track structure. When the deformation of the track structure in different layers is not coordinated, it will trigger the evolution of inter-layer damage. Under the action of seismic cyclic loading, the evolution of inter-layer damage will be significantly aggravated, and the aggravated inter-layer damage will further lead to the deterioration of track geometric smoothness. This cycle repeats, causing irreversible adverse effects on the service performance and fatigue life of the track structural components. See also Figure 10The demonstration of the interlayer damage evolution mechanism of CRTS III slab track under pier settlement and seismic loads considers five spans of beams, with roadbed sections on both sides of the bridge cross-section. When pier settlement occurs, the track structure exhibits downward deformation at the settled pier location and upward arching deformation at the adjacent pier location. In the CRTS III slab track, the base plate and box girder are anchored together by 26 pre-embedded steel bars, and the track slab and self-compacting concrete are connected by double rows of U-shaped steel bars and steel mesh, maintaining contact between the various structural layers. However, due to the isolation layer between the self-compacting concrete and the base plate, the interlayer bond between them is weak. Therefore, during pier settlement, the interlayer relationship at the SP (pier adjacent to AP) and AP (settled pier) locations easily evolves from a contact state to a separation state. Based on the structural characteristics of the CRTS III slab track, the rails and fasteners are the key factors inducing interlayer separation. Taking the AP position on the left side of SP as an example, when the pier settles, the beam on the left side of SP rotates, causing the track structure at the beam end to be lifted. This results in upward deformation of the rail at that position. This deformation is transmitted to the track slab-self-compacting concrete composite slab through the fasteners, pulling the composite slab upward. The deformation of the composite slab cannot be transmitted downward through the isolation layer, leading to deformation incoordination between its base plate and box girder composite beam, ultimately causing inter-layer damage and voiding. The causes of inter-layer damage at other locations are similar to the above mechanism. Under seismic load, inter-layer damage evolves dynamically with the earthquake time history, exacerbating track deformation. However, after the earthquake ends, the track system tends to stabilize, and the inter-layer damage area does not significantly expand. Therefore, this embodiment ignores the small cumulative damage effect of seismic action on the inter-layer structure.

[0053] To reveal the development law of interlayer damage in CRTS III type slab track, the settlement amplitude of the bridge pier was set to 0 mm-20 mm, and the settlement step size was taken as 0.0001 mm. Based on the damage evolution model established in this embodiment, the interlayer damage length and damage height between the self-compacting concrete and the base plate were calculated. The results are shown in Figures 11(a) and 11(b). A total of 10 key indicators were examined, including the damage length and damage height of voids 1-5. The following conclusions are drawn from the results: (a) The damage distribution at the AP positions on both sides of SP is not centrally symmetrical. Although the damage evolution trend of symmetrical positions (Void 1 and Void 5, Void 2 and Void 4) is consistent, the damage length and damage height of each symmetrical group are significantly different in numerical value. The reason is that the fixed support constrains the longitudinal displacement of the right end of the first span beam, which causes the arch deformation of the rail at the AP position on the left to be greater than that on the right, ultimately leading to more obvious interlayer damage.

[0054] (b) The damage length and height of the voids 1-5 both showed a nonlinear positive correlation with the pier settlement. As the settlement increased, the growth rate of the damage length gradually leveled off. This is because, within the stiffness bearing threshold range of the track slab-self-compacting concrete composite slab, the deformation of the composite slab approached the critical state as the settlement increased.

[0055] (c) As the pier settlement increases, the increase in damage length at voids 2 and 4 is not significantly different from that at other locations, but the increase in damage height is significantly smaller. When the settlement reaches 20 mm, the damage height at voids 2 and 4 is only about 0.05 mm. Therefore, the amplification effect of interlayer damage at these two locations on track displacement under seismic loading can be ignored.

[0056] S3 includes: S3.1 Based on the track damage evolution model corresponding to different load steps, different pier settlement amplitudes are selected and coupled with two working conditions, design earthquake and rare earthquake, respectively, to calculate the track residual irregularity; To investigate the distribution pattern of residual track irregularities under the coupled action of pier settlement and seismic load, this embodiment takes a CRTS III slab track-slab simply supported beam bridge system with 5 spans and 14m pier height as the research object. Based on the damage evolution model, the residual track irregularities are calculated under the conditions of PGA of 0.3g (design earthquake) and 0.57g (rare earthquake). To establish a benchmark for comparison with the results under the coupled action of seismic load and pier settlement, the residual track irregularities are first calculated considering only the seismic load, as shown in Figures 12(a) and 12(b). It can be seen that the amplitude of residual track irregularities under the rare earthquake condition is significantly larger than that under the design earthquake condition, but the residual irregularities under both conditions exhibit the dual characteristics of "small at both ends and large in the middle" and "segmented distribution". In the CRTS III type slab track-simply supported beam bridge system, the mid-span simply supported beam has low constraint stiffness, a prominent stress concentration effect, significant beam displacement response, and strong track inertia. The superposition of multiple factors leads to a larger magnitude of residual deformation during earthquakes. Compared to the CRTS II type longitudinally connected slab track system, the CRTS III type slab track relies solely on the rails at beam joints to transfer mechanical forces between beam spans, lacking the synergistic constraint of a longitudinally connected structure. This directly results in significant abrupt deformation changes at the beam span connections, ultimately leading to a "segmented distribution" of track residual irregularities.

[0057] Bridge pier settlement induces inter-layer damage to the track structure, exacerbates the development of residual track irregularities, and significantly increases the risk of post-earthquake traffic safety. To quantify the impact of bridge pier settlement on residual track irregularities, bridge pier settlement amplitudes of 5 mm, 10 mm, 15 mm, and 20 mm were selected as the study conditions. These were coupled with seismic conditions with PGA values ​​of 0.3g (design earthquake) and 0.57g (rare earthquake), respectively, to calculate residual track irregularities. The calculation results of residual track irregularities under different bridge pier settlement amplitudes when the PGA is 0.3g are shown in Figures 13(a) to 13(d), respectively. The calculation results of residual track irregularities under different bridge pier settlement amplitudes when the PGA is 0.57g are shown in Figures 14(a) to 14(d), respectively. As can be seen, compared with the track residual irregularities under only seismic load in Figures 12(a) and 12(b), after introducing the pier settlement condition, the overall amplitude of the track residual irregularities did not show a significant difference. However, obvious deformation abrupt changes occurred at local locations SP and AP. This is because the track structure is a typical layered composite system, and the interlayer interface is the key carrier for force and deformation transmission. Once interlayer damage occurs, it will directly destroy the force transmission path of the structure, leading to local stress concentration and inducing abrupt changes in residual irregularities. The specific manifestations under different pier settlement amplitudes are as follows: When the pier settlement is 5 mm, the maximum height of the interlayer damage approaches 0, and the interlayer interface remains basically in contact. Therefore, the residual track irregularity values ​​under the coupled working condition and the seismic-only working condition are close to 0. When the settlement increases to 10 mm, the length and height of the interlayer damage of voids 1 and 3 increase significantly, resulting in obvious local residual irregularity values ​​at the AP and SP positions on the left side. The length of the local difference area also basically matches the length of the corresponding interlayer damage, further confirming the direct control effect of the damage range on the residual irregularity influence area. When the settlement reaches 15 mm, the development degree of void 5 gradually approaches that of voids 1 and 3, causing the displacement and force transmission at void 5 to be interrupted, resulting in significant local residual irregularity values ​​at the AP position on the right side. When the settlement amplitude increases to 20 mm, the local residual irregularity values ​​at each key position further increase. Overall, the aggravating effect of pier settlement on residual track irregularities is mainly achieved by inducing interlayer damage that disrupts the load transmission continuity of the track structure. As the settlement value increases, the influence range of interlayer damage gradually expands and the degree of influence continues to intensify, ultimately leading to a more significant difference in local residual irregularities between the AP and SP locations.

[0058] In this embodiment, the curves of different colors in Figures 12(a) to 14(d) correspond to different ground motions.

[0059] When the PGA increased from 0.3g to 0.57g, the influence of pier settlement on the aggravation effect of track residual irregularities did not change significantly, confirming that this aggravation effect is significantly correlated with interlayer damage. However, referring to Figures 14(a) to 14(d), after introducing the settlement condition, the difference in track residual irregularities under a 0.57g ground motion showed a significant increasing trend. In summary, the aggravation effect of pier settlement on track residual irregularities is positively correlated with the pier settlement amplitude and PGA; the larger the settlement value, the wider the range of influence of the aggravation effect, and the larger the PGA, the more significant the degree of influence of the aggravation effect.

[0060] S3.2. Based on the statistical characteristics of track residual irregularities, wavelet packet transform is used to construct characteristic residual irregularities.

[0061] As can be seen from Figures 13(a) to 14(d), under the coupled action of seismic load and pier settlement, the residual track irregularities exhibit significant stochastic characteristics. It is difficult to establish a deterministic numerical mapping relationship between seismic motion parameters and residual irregularities, which poses a challenge to post-earthquake traffic safety assessment. Therefore, this embodiment constructs characteristic residual irregularities based on their statistical features to provide irregularity input for post-earthquake traffic simulation.

[0062] S3.2 includes: S3.2.1 Perform wavelet packet transform on the residual irregularities of the track to obtain the wavelet packet coefficient matrix. ; The residual irregularity curve can be regarded as a typical non-stationary random signal. Statistical analysis from the time domain alone is insufficient to fully characterize its spectral features, leading to distortion in post-earthquake traffic safety analysis results. To avoid the irreconcilable time-frequency resolution defects caused by the fixed window length of the short-time Fourier transform, and the insufficient high-frequency resolution caused by the recursive decomposition of low-frequency approximate components and the lack of further subdivision of high-frequency detail components in the wavelet transform, this embodiment uses wavelet packet transform to perform time-frequency analysis and feature extraction on the residual irregularity signal.

[0063] The residual irregular sample library is denoted as The residual irregularities in the track are denoted as , Number the ground motion.

[0064] In S3.2.1, the specific formulas for the wavelet packet coefficients of each layer are as follows: ; in: This represents the coefficients of the 0th node at the 0th level of the wavelet packet decomposition, i.e., the residual irregularities of the original trajectory; j This indicates the number of layers in the wavelet packet decomposition. , J Indicates the maximum number of floors; , Indicates the first j Layer Wavelet packet coefficients of each node; and They represent Low-frequency and high-frequency components; and g These represent high-pass and low-pass filters, respectively. Indicates the coefficient index of the filter; These are discrete coordinates used to locate the coefficients of each layer after wavelet decomposition. In S3.2.1, the wavelet packet coefficient matrix The specific expression is as follows: ; in: N This represents the total number of columns in the wavelet packet coefficient matrix; S3.2.2. Perform a logarithmic transformation on the wavelet packet coefficient matrix to construct the logarithmic set { D}={log 10 ( d j )}; and define the kurtosis coefficient of random samples in the logarithmic set. Skewing coefficient ; In S3.2.2, the kurtosis coefficient of the random sample Skewing coefficient The specific formula is as follows: ; ; in: For random samples, For sample size; It is a natural number index variable used to represent the sample number. Take 1 to 0 natural numbers; Represents the mean of a random sample; S3.2.3, Based on kurtosis coefficient Skewing coefficient Define statistical functions and discriminant function ; In S3.2.3, the statistical function and discriminant function The specific formula is as follows: ; ; in: For chi-square distribution Quantiles The significance level; S3.2.4, when When the value equals 0, assuming the population D corresponding to the random sample follows a normal distribution, then we define an upper bound. The specific quantiles in the normal population D are as follows: ; in: A 1 and A 2 represents the first-order and second-order sample intervals, i.e., the sample mean and sample variance, respectively; Represents the one-sided quantiles of the standard normal distribution; S3.2.5, Take the significance level The value is 0.05, based on the statistical upper bound determined in step S3.2.4. Wavelet packet coefficients that meet the preset normality test conditions are selected, and feature residual irregularities are reconstructed using the wavelet packet reconstruction algorithm.

[0065] In S3.2.5, the specific formula for the wavelet packet reconstruction algorithm is as follows: ; in: H and G These represent the low-pass and high-pass filters used in wavelet packet reconstruction, respectively.

[0066] Referring to Figures 15(a) and 15(b), it can be seen that the characteristic residual irregularity curves under different pier settlement conditions have significant differences at the SP and AP positions, indicating that interlayer damage has a significant impact on track residual irregularity.

[0067] To demonstrate the rationality of the characteristic residual irregularity construction method, this embodiment uses a pier settlement of 20mm as an example. The characteristic residual irregularities and the aforementioned set of 40 track residual irregularities are used as the irregularity excitation in the train-track-bridge system coupling model. The train speed is set to 300km / h, and the lateral acceleration of the train body is calculated, as shown in Figures 16(a) and 16(b). The results show that, except for a few scattered points, the peak lateral wheel-rail forces corresponding to the characteristic residual irregularities are all higher than the corresponding peak values ​​of the 40 track residual irregularity sets. This result shows good consistency with the preset significance level, verifying the rationality of the characteristic residual irregularity construction method proposed in this embodiment. The design response spectrum is imported into the NGA-West2 seismic ground motion database (https: / / ngawest2.berkeley.edu / ), and the 40 sets of seismic ground motions with the highest matching degree are selected.

[0068] Furthermore, to demonstrate the applicability of the characteristic residual irregularity construction method, the design response spectrum was imported into the NGA-West2 seismic motion database, and the five seismic waves with the highest matching degree were selected. The track residual irregularity set was calculated using the track damage evolution model. The characteristic residual irregularities and the track residual irregularity set were used as irregularity excitations in the train-track-bridge system coupling model, respectively. The train speed was set to 350 km / h, and the lateral acceleration of the train body was calculated, as shown in Figures 17(a) and 17(b). The five different colored bars correspond to the five seismic waves. It is easy to see that, under different pier settlement values ​​and PGA, the peak values ​​of the lateral acceleration of the train body corresponding to the five newly added track residual irregularities are all smaller than the peak values ​​corresponding to the characteristic residual irregularities, indicating that the proposed construction method has good applicability under similar seismic parameters and also has a certain safety margin.

[0069] This embodiment establishes a damage evolution model for CRTS III type slab track ballastless track under the coupled effects of seismic load and pier settlement, reveals the inter-layer evolution mechanism and evolution law of track, studies the distribution pattern of track residual irregularities, proposes a characteristic residual irregularity construction method based on wavelet packet transform, and quantifies the aggravating effect of pier settlement on track residual irregularities. The main conclusions are as follows: (1) The damage evolution model established in this embodiment shows good agreement with the results of shaking table tests and numerical model calculations, verifying the correctness of the model. During mechanical analysis, this model can effectively identify interlaminar damage locations and achieve adaptive mesh evolution. The simplified design method used in the model can shorten the calculation time by approximately 40% while ensuring calculation accuracy.

[0070] (2) Under the coupled action of seismic load and pier settlement, the interlayer damage of CRTS III type slab track is mainly concentrated at the interface between self-compacting concrete and base plate. The damage areas that have a significant impact on the track residual irregularity are mainly distributed in the middle of SP and the outer side of AP.

[0071] (3) There is a nonlinear positive correlation between the interlayer damage of the track and the settlement of the bridge pier. As the settlement increases, the growth rate of the interlayer damage length gradually becomes slower. Among them, the growth rate of the damage length of Void 2 and Void 4 is not significantly different from that of other locations, but the growth rate of the damage height of the two is significantly smaller.

[0072] (4) The aggravating effect of pier settlement on residual track irregularities is mainly achieved by inducing interlayer damage and disrupting the load transmission continuity of the track structure. The larger the settlement value, the wider the range of the aggravating effect; the larger the PGA (Proportional Gain Aggregate Scale), the more significant the aggravating effect. (5) The method for constructing track feature residual irregularities based on wavelet packet transform makes up for the shortcomings of short-time Fourier transform and wavelet transform in terms of time-frequency resolution. The constructed feature residual irregularities have a reasonable safety threshold and can be used as irregularity excitation input for post-earthquake driving performance analysis of high-speed railway track-bridge system.

[0073] This embodiment provides a readable storage medium storing computer program instructions, which, when executed by a processor, implement the feature irregularity construction method based on the damage evolution model as described above.

[0074] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0075] This embodiment also includes an electronic device, comprising: at least one processor, at least one memory, and computer program instructions stored in the memory, wherein the computer program instructions are executed by the processor to construct the feature irregularity based on the damage evolution model as described above.

[0076] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the electronic device.

[0077] The electronic device can be a mobile phone, desktop computer, laptop, handheld computer, cloud server, or other computing device. The electronic device may include, but is not limited to, processors and memory. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0078] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the electronic device, connecting all parts of the electronic device via various interfaces and lines.

[0079] The memory can be used to store the computer program and / or modules. The processor implements the computer program by running or executing the computer program and / or modules stored in the memory, and by calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital card (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0080] If the modules / units integrated in the electronic device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0081] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention. All equivalent structural transformations made under the inventive concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A method for constructing a feature irregularity based on a damage evolution model, the method comprising: determining a damage evolution model for a material; determining a feature irregularity for the material based on the damage evolution model; and outputting the feature irregularity. Includes the following steps: S1: Select a beam bridge system as the research object; S2: Establish an orbital damage evolution model based on a simplified orbital structure model and an adaptive grid evolution mechanism for the research object; S3: Characteristic residual irregularities are constructed based on track damage evolution models under different load steps and different pier settlement amplitudes; S3 includes: S3.1 Based on the track damage evolution model corresponding to different load steps, different pier settlement amplitudes are selected and coupled with two working conditions, design earthquake and rare earthquake, respectively, to calculate the track residual irregularity; S3.

2. Based on the statistical characteristics of track residual irregularities, wavelet packet transform is used to construct characteristic residual irregularities.

2. The feature irregularity construction method based on the damage evolution model according to claim 1, characterized in that, S2 includes: S2.

1. Model the research object to obtain a traditional track structure model; S2.

2. The track slab and self-compacting concrete, which are effectively connected by U-shaped steel bars and pre-embedded steel bars in the traditional track structure model, as well as the base plate and box girder, are regarded as two composite structural systems that satisfy the assumption of interface displacement continuity and stress transfer coordination conditions, respectively, to obtain a simplified track structure model. S2.3 Introducing an adaptive mesh evolution mechanism, by detecting the stress state of the springs between the self-compacting concrete and the base plate, identifying the decoupled areas and performing adaptive mesh refinement, an optimized track structure model is obtained; S2.

4. Based on the track structure optimization model, the characteristics of each component of the research object are simulated, and the constitutive relationship of each component is obtained through experiments and field tests to obtain the track damage evolution model.

3. The feature irregularity construction method based on the damage evolution model according to claim 2, characterized in that, In S2.1, when modeling the research object, it is assumed that each component of the research object satisfies the following conditions: The steel reinforcement and concrete deform in coordination, the anchorage length meets the design requirements, and the steel reinforcement slippage effect is ignored. Ignoring microcracks and local inhomogeneities in concrete, a homogenized continuous medium model is used to model the concrete. The interlayer shear stress between the track slab and the self-compacting concrete, and between the base plate and the box girder, shall not exceed the bond strength limit to ensure interlayer continuity.

4. The feature irregularity construction method based on the damage evolution model according to claim 3, characterized in that, S2.3 includes: S2.3.1 Initialize disconnection status indicators Disconnection length and the number of disconnect springs ; S2.3.2 Setting the number of load steps And set the initial grid size. and initial spring stiffness ; S2.3.

3. Perform load step operations on the simplified model of the track structure according to the set load sequence. After the current load step calculation is completed, cyclically check the stress state of each interlayer spring between the self-compacting concrete and the base plate, and determine the interlayer decoupling state based on the spring force of the interlayer spring. Specifically, when the spring force is greater than 0, the decoupling state index corresponding to that interlayer spring is... When the spring force is 0, the interlayer spring is in a disengaged state, proceeding to S2.3.4; when the spring force is 0, the disengagement state index... If the value is 1, the system is not in a state of interlayer disconnection and proceeds to S2.3.

5. S2.3.4 Calculate the decoupling length of the decoupling region based on the decoupling state index of the interlayer spring and the element length, and refine the corresponding mesh region locally according to the coordinate information of the interlayer spring and the decoupling length. S2.3.5, Order ,judge If the load step count exceeds the set total load step count, proceed to S2.3.6 and output the structural response, decoupled region distribution, and refined track structure optimization model under each load step; otherwise, return to S2.3.

3.

5. The feature irregularity construction method based on the damage evolution model according to claim 4, characterized in that, In S2.3.4, the specific formula for calculating the disconnection length is as follows: ； in: This is the length of the disconnection; This represents the number of continuously disengaged springs; The unit length; This refers to the numbering of the interlayer springs; The specific formula for local mesh refinement is as follows: ； in: and The spring stiffness is for coarse and fine mesh grids, respectively. and These are the cell lengths for the coarse and fine meshes, respectively.

6. The method for constructing feature irregularities based on a damage evolution model according to any one of claims 1-5, characterized in that, The composite structural system consisting of the track slab and self-compacting concrete is regarded as a composite slab, and the composite structural system consisting of the base plate and the box girder is regarded as a composite beam. In S2.4, three-dimensional beam elements are used to simulate the rails, composite plates, composite beams, and piers of the research object. Elastic custom sections are used to characterize the geometric features of the rails, composite plates, and composite beams, and generalized sections are used to simulate the nonlinear plastic behavior of the piers. The abutments of the research object are simplified to a rigid domain, and spring damper elements are set at the bottom of the pile foundation of the research object to simulate the pile-soil interaction at the bottom of the abutments, roadbed, and piers. Combined spring elements are used to simulate the elastic cushion layer and supports. Nonlinear spring elements are used to simulate fasteners and isolation layers, and unidirectional constraint springs are set through the nonlinear constitutive definition function of the nonlinear spring elements. A 20m long roadbed section along the line direction is taken as the model boundary, and fixed constraints are applied to the two ends of the roadbed section.

7. The feature irregularity construction method based on the damage evolution model according to claim 6, characterized in that, S3.2 includes: S3.2.1 Perform wavelet packet transform on the residual track irregularities to obtain the wavelet packet coefficient matrix. ; S3.2.2 Perform a logarithmic transformation on the wavelet packet coefficient matrix to construct the logarithmic set. And define the kurtosis coefficient of random samples in the logarithmic set. Skewing coefficient ; S3.2.3, Based on kurtosis coefficient Skewing coefficient Define statistical functions and discriminant function ; S3.2.4, when When the value equals 0, assuming the population D corresponding to the random sample follows a normal distribution, then we define an upper bound. The specific quantiles in the normal population D are as follows: ； in: A 1 and A 2 represents the first-order and second-order sample intervals, i.e., the sample mean and sample variance, respectively; Represents the one-sided quantiles of the standard normal distribution; S3.2.5, Take the significance level The value is 0.05, based on the statistical upper bound determined in step S3.2.

4. Wavelet packet coefficients that meet the preset normality test conditions are selected, and feature residual irregularities are reconstructed using the wavelet packet reconstruction algorithm.

8. The feature irregularity construction method based on the damage evolution model according to claim 7, characterized in that, In S3.2.1, the specific formulas for the wavelet packet coefficients of each layer are as follows: ； in: This represents the coefficients of the 0th node at the 0th level of the wavelet packet decomposition, i.e., the residual irregularities of the original trajectory. The track remains uneven. i Number the earthquake motion; j This indicates the number of layers in the wavelet packet decomposition. , J Indicates the maximum number of floors; , Indicates the first j Layer Wavelet packet coefficients of each node; and They represent Low-frequency and high-frequency components; and g These represent high-pass and low-pass filters, respectively. Indicates the coefficient index of the filter; These are discrete coordinates used to locate the coefficients of each layer after wavelet decomposition. In S3.2.1, the wavelet packet coefficient matrix The specific expression is as follows: ； in: N This represents the total number of columns in the wavelet packet coefficient matrix; In S3.2.2, the kurtosis coefficient of the random sample Skewing coefficient The specific formula is as follows: ； ； in: For random samples, For sample size; It is a natural number index variable used to represent the sample number. Take 1 to 0 natural numbers; Represents the mean of a random sample; In S3.2.3, the statistical function and discriminant function The specific formula is as follows: ； ； in: For chi-square distribution Quantiles The significance level; In S3.2.5, the specific formula for the wavelet packet reconstruction algorithm is as follows: ； in: H and G These represent the low-pass and high-pass filters used in wavelet packet reconstruction, respectively.

9. A readable storage medium, characterized in that, It stores computer program instructions, which, when executed by a processor, implement the feature irregularity construction method based on the damage evolution model as described in any one of claims 1 to 8.

10. An electronic device, characterized in that, include: At least one processor, at least one memory, and computer program instructions stored in the memory, wherein the computer program instructions are executed by the processor as described in any one of claims 1 to 8, a feature non-compliance construction method based on a damage evolution model.

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