Rail-bridge system earthquake resistance evaluation method, medium and device

Abstract

This invention relates to the field of railway seismic safety technology, specifically to a method, medium, and equipment for seismic assessment of track-bridge systems. The method includes: establishing a finite element model of the track-bridge system; performing nonlinear time-history analysis on the track-bridge system under different operating conditions; analyzing the controlling factors of the seismic response of the track-bridge system; establishing a mapping relationship between the seismic response of the track structure and the seismic response of the main girder; calculating the seismic response of the main girder and evaluating the seismic displacement response of the track structure; and achieving seismic assessment of the track-bridge system. This invention can be applied to all current high-speed railway bridge types and tracks. Based on the mapping relationship, it can indirectly and quickly achieve seismic assessment of track-bridge systems based on train performance, without requiring extensive and time-consuming finite element simulation calculations of the train-track-bridge system. This effectively improves efficiency, reduces costs, simplifies calculations, and provides relatively accurate results.

Description

Technical Field

[0001] This invention relates to the field of railway earthquake safety technology, specifically to a method, medium, and equipment for seismic assessment of track-bridge systems. Background Technology

[0002] To shorten track distances, high-speed railways utilize numerous bridges in their construction. Many of these bridges are located in earthquake-prone areas, and earthquakes can damage the high-speed railway track-bridge system. This directly impacts post-earthquake operational safety and rapid emergency response. Therefore, quickly assessing the seismic response of high-speed railway track-bridge systems is crucial.

[0003] Currently, high-speed railway bridges inevitably experience seismic responses such as relative displacement at the beam ends and acceleration of the main beam under seismic loads. Existing methods for calculating the seismic response of high-speed railway bridges generally fall into two categories: one involves establishing a refined finite element model based on the structural and site characteristics of the high-speed railway track-bridge system, inputting seismic excitation, obtaining the response results, and then analyzing them to obtain the seismic response; the other involves establishing a seismic monitoring system to identify and extract structural damage characteristics through the structural response signals during an earthquake, thereby obtaining the seismic response.

[0004] However, the aforementioned research methods require extremely high accuracy from the finite element model. Post-earthquake nonlinear time-history analysis using finite element methods is resource-intensive and time-consuming, failing to quickly assess post-earthquake damage and thus hindering rapid emergency response. Furthermore, the sheer number of monitoring devices and the complexity of daily maintenance necessitate highly specialized knowledge and skills in signal processing. Moreover, existing simplified calculation methods for the seismic response of high-speed railway bridges focus solely on the bridge structure, neglecting track structure and post-earthquake traffic performance. This approach cannot treat the high-speed railway bridge as a whole for damage analysis, compromising the accuracy of the results. In addition, recent earthquake disasters have shown that track structures are more susceptible to seismic damage than bridge structures, directly threatening the safety of traffic on the bridge.

[0005] In summary, it is necessary to provide a universal and simplified calculation method that fully considers high-speed trains, bridges, and track systems as a whole, obtains the seismic response of track-bridge structures more accurately, and quickly realizes the seismic assessment of track-bridge systems based on train performance. Summary of the Invention

[0006] The purpose of this invention is to provide a versatile, efficient, and accurate method, medium, and equipment for seismic assessment of track-bridge systems. The specific technical solution is as follows:

[0007] A seismic assessment method for a track-bridge system includes the following steps:

[0008] S1: Establish a finite element model of the track-bridge system of high-speed railway;

[0009] S2: Based on the response spectrum, artificial seismic waves are generated as the seismic excitation of the track-bridge system, and nonlinear time history analysis is performed on the track-bridge system under different working conditions to obtain the average value of the seismic response of the track structure under each working condition.

[0010] S3: Based on the average value of the seismic response of the track structure, analyze the controlling factors of the seismic response of the track structure under different working conditions;

[0011] S4: Based on the aforementioned control factors, establish a mapping relationship between the seismic response of the track structure and the seismic response of the main beam;

[0012] S5: The seismic response of the main beam is calculated using a nonlinear time history calculation method. Based on the mapping relationship established in S4, the seismic displacement response of the track structure is evaluated.

[0013] S6: Based on the mapping relationship established in S4, set the damage limits for the main components of the bridge structure, perform seismic verification of the main components of the bridge structure, and realize the seismic assessment of the track-bridge system.

[0014] Preferably, S1 specifically includes:

[0015] The track-bridge system of high-speed railways was selected as the target object.

[0016] In the track-bridge system, the concrete main beam is simulated using elastic beam elements, while the base plate, track plate, and rails are simulated using tensile fracture beam elements.

[0017] Based on the OpenSEES platform, this paper integrates the simulation elements used in the bridge and track structures to establish a finite element model of the high-speed railway track-bridge system that takes into account both material nonlinearity and constraint nonlinearity and can accurately simulate the structural response of the target object under seismic motion.

[0018] Preferably, S2 specifically includes:

[0019] Based on the target response spectrum, the characteristic period is adjusted to generate artificial seismic waves in batches.

[0020] The peak ground acceleration of each seismic wave is adjusted and used as the longitudinal and lateral seismic excitation input to the finite element model of the track-bridge system. Nonlinear time history analysis is performed on the track-bridge system under different working conditions to obtain the average value of the seismic response of the track structure under each working condition.

[0021] The different working conditions are divided according to the support type and beam end connection of the track-bridge system.

[0022] Preferably, the control factors are specifically:

[0023] When there are gaps between the main beams, the seismic response of the track structure is controlled by the relative displacement between the beam ends;

[0024] When a connecting beam device is used at the ends of adjacent beams, the seismic response of the track structure is controlled by the acceleration of the main beam.

[0025] Preferably, S4 specifically includes:

[0026] Based on the aforementioned control factors, a quantitative analysis was conducted on all possible indicators of the seismic response of the main girder that could control the seismic response of the track structure.

[0027] Mathematical methods were used to perform regression analysis on the seismic response of the track structure and the seismic response of the main beam to obtain the corresponding mapping relationship.

[0028] Preferably, the mapping relationship is specifically:

[0029] For track-bridge systems without a connecting beam device, the seismic response of the track structure is a power function of the relative displacement at the beam ends, and other factors do not play a controlling role.

[0030] For track-bridge systems using a continuous beam assembly, the seismic response of the track structure is linearly related to the acceleration of the main beam, and other factors do not play a controlling role.

[0031] Preferably, S5 specifically includes:

[0032] A nonlinear time history calculation method for bridge structures with a simplified two-degree-of-freedom system is used, while considering the influence of uncertainties in bridge parameters, to quickly calculate the seismic response of the bridge structure and obtain its seismic response index.

[0033] The seismic response indicators of bridges include the relative displacement at the beam ends and the acceleration of the main beam. Based on the aforementioned mapping relationship, the seismic displacement response of the track structure can be quickly estimated using the maximum relative displacement at the beam ends and the maximum acceleration of the main beam.

[0034] Preferably, S6 specifically includes:

[0035] Based on the safety limits of track deformation under different damage levels and the deformation limits of related track structures calculated from existing post-earthquake bridge traffic simulations, the limits of the obtained bridge seismic response indices are calculated in reverse according to the mapping relationship for different bridge types and track types.

[0036] A nonlinear time history calculation method for bridge structures using a simplified two-degree-of-freedom system is used to quickly calculate the seismic response of piers, bearings, and the bridge itself, determine whether the seismic response index limits are met, and rapidly assess the track structure response or post-earthquake traffic performance.

[0037] The present invention also provides a readable storage medium having stored computer program instructions thereon, which, when executed by a processor, implement the seismic assessment method for track-bridge systems as described above.

[0038] 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 as described in the seismic assessment method for track-bridge systems.

[0039] The application of the technical solution of the present invention has the following beneficial effects:

[0040] A method for seismic assessment of a track-bridge system includes: S1: establishing a finite element model of the track-bridge system of a high-speed railway; S2: generating artificial seismic waves based on the response spectrum as the seismic excitation of the track-bridge system, and performing nonlinear time history analysis on the track-bridge system under different working conditions to obtain the average value of the track structure seismic response for each working condition; S3: analyzing the controlling factors of the track structure seismic response under different working conditions based on the average value of the track structure seismic response; S4: establishing a mapping relationship between the track structure seismic response and the main beam seismic response based on the said controlling factors; S5: calculating the main beam seismic response using a nonlinear time history calculation method, and evaluating the seismic displacement response of the track structure based on the mapping relationship established in S4; S6: setting damage limits for the main components of the bridge structure based on the mapping relationship established in S4, performing seismic verification calculations for the main components of the bridge structure, and realizing the seismic assessment of the track-bridge system. This method is suitable for all current high-speed railway bridge types and track forms, establishing a mapping relationship between the seismic responses of the track structure and the bridge structure through the seismic response of the track-bridge system and its influencing factors. Based on existing research on track structure damage limits based on post-earthquake train performance, damage limits for the main components of the bridge structure were set. Thus, through seismic response analysis of the bridge structure and seismic verification of the main components, and based on the aforementioned mapping relationship, seismic assessment of the track-bridge system based on train performance can be achieved indirectly and quickly. The method of this invention eliminates the need for extensive and time-consuming finite element simulation calculations of the train-track-bridge system, effectively improving efficiency, reducing costs, and simplifying calculations. Furthermore, the calculation results are relatively accurate, providing a theoretical basis for in-depth research on the train safety and seismic design of high-speed railway track-bridge systems.

[0041] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0042] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0043] Figure 1 This is a schematic flowchart of a seismic assessment method for a track-bridge system according to an embodiment of the present invention;

[0044] Figure 2 This is the finite element model of the high-speed railway track-bridge system established in the embodiments of the present invention;

[0045] Figure 3 This is a schematic diagram illustrating the seismic response of a portion of the track structure in a track-bridge system under various working conditions in embodiments of the present invention;

[0046] Figure 4 The following is a correspondence between the transverse bridge response of the track structure under longitudinal earthquake and the longitudinal bridge relative displacement at the beam end in an embodiment of the present invention: (a-1) is the correspondence between the relative displacement at the beam end and the fastener displacement; (a-2) is the correspondence between the relative displacement at the beam end and the CA layer displacement; (a-3) is the correspondence between the relative displacement at the beam end and the sliding layer displacement.

[0047] Figure 5 This invention presents the correspondence between the transverse bridge response of the track structure under transverse earthquake and the transverse bridge relative displacement at the beam end in an embodiment of the invention, wherein: (b-1) is the correspondence between the relative displacement at the beam end and the fastener displacement; (b-2) is the correspondence between the relative displacement at the beam end and the CA layer displacement; and (b-3) is the correspondence between the relative displacement at the beam end and the sliding layer displacement.

[0048] Figure 6 This invention presents the correspondence between the transverse bridge response of the track structure and the longitudinal bridge acceleration response of the main beam under longitudinal earthquake conditions in this embodiment of the invention, wherein: (c-1) is the correspondence between the main beam acceleration and the fastener displacement; (c-2) is the correspondence between the main beam acceleration and the CA layer displacement; and (c-3) is the correspondence between the main beam acceleration and the sliding layer displacement.

[0049] Figure 7 This invention presents the correspondence between the transverse bridge response of the track structure and the longitudinal bridge acceleration response of the main beam under a transverse earthquake, wherein: (d-1) is the correspondence between the main beam acceleration and the fastener displacement; (d-2) is the correspondence between the main beam acceleration and the CA layer displacement; and (d-3) is the correspondence between the main beam acceleration and the sliding layer displacement. Detailed Implementation

[0050] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0051] In one embodiment, see Figure 1 A seismic assessment method for a track-bridge system includes the following steps:

[0052] S1: Establish a finite element model of the track-bridge system of the high-speed railway, such as Figure 2 As shown, it specifically includes:

[0053] The target object is the track-bridge system of high-speed railway; the target object can be any existing bridge type and track form;

[0054] The concrete main beam in the track-bridge system is simulated using elastic beam elements, while the base plate, track plate, and rails are simulated using tensile fracture beam elements. Two working conditions are provided: gaps between adjacent beam ends or the use of connecting beam devices. It is assumed that the connecting beam devices are rigidly constrained during an earthquake. The element properties of other components are defined according to the situation.

[0055] Based on the OpenSEES platform, this paper integrates the simulation elements used in the bridge and track structures to establish a finite element model of the high-speed railway track-bridge system that takes into account both material nonlinearity and constraint nonlinearity and can accurately simulate the structural response of the target object under seismic motion.

[0056] S2: Based on the response spectrum, artificial seismic waves are generated as the seismic excitation for the track-bridge system, and nonlinear time history analysis is performed on the track-bridge system under different working conditions, specifically including:

[0057] Based on the target response spectrum, the characteristic period is adjusted to generate artificial seismic waves in batches.

[0058] The peak ground acceleration of each seismic wave was adjusted and used as the longitudinal and lateral seismic excitation input to the finite element model of the track-bridge system. Nonlinear time-history analysis was performed on the track-bridge system under different operating conditions to obtain the average value of the track structure's seismic response for each condition. Figure 3 As shown;

[0059] The different working conditions are divided according to the support type and beam end connection of the track-bridge system. In this specific embodiment, there are 7 types: ordinary support without failure, ordinary support with failure, ordinary support with failure + connecting beam device, uniform friction pendulum support, concave friction pendulum support, uniform friction pendulum support + connecting beam device, and concave friction pendulum support + connecting beam device. In engineering applications, the classification can be made according to the actual situation.

[0060] S3: Based on the average seismic response of the track structure, analyze the controlling factors of the seismic response of the track structure under different working conditions, specifically including:

[0061] Based on the average value of the seismic response of the track structure, the controlling factors of the seismic response of the track structure under different working conditions are analyzed. These controlling factors depend on the measurement index of the seismic response of the main beam.

[0062] The control factors are specifically:

[0063] When there are gaps between the main beams, the seismic response of the track structure is controlled by the relative displacement between the beam ends;

[0064] When a connecting beam device is used at the ends of adjacent beams, the seismic response of the track structure is controlled by the acceleration of the main beam.

[0065] S4: Based on the aforementioned control factors, establish a mapping relationship between the seismic response of the track structure and the seismic response of the main beam, specifically including:

[0066] Based on the aforementioned control factors, a quantitative analysis was conducted on all possible indicators of the seismic response of the main girder that could control the seismic response of the track structure, including but not limited to relative displacement at the girder ends and acceleration of the main girder.

[0067] Mathematical methods were used to perform regression analysis on the seismic response of the track structure and the main girder to obtain the corresponding mapping relationship, such as... Figures 4-7 As shown in the figures, the coefficient of determination R of the regression formula in each figure is... 2 Almost all values ​​are greater than 0.92, indicating that the mapping relationship established in this embodiment can describe the relationship between the seismic response of the track structure and the seismic response of the main beam in a good way.

[0068] The mapping relationship is specifically as follows:

[0069] For track-bridge systems without a connecting beam device, the seismic response of the track structure is a power function of the relative displacement at the beam ends, and other factors do not play a controlling role. Since the beam end displacement is close to the support displacement in actual engineering, the adjacent support displacement at the beam end can be used to replace the beam end displacement.

[0070] For track-bridge systems using a coupled beam assembly, the seismic response of the track structure is linearly related to the acceleration of the main beam. The acceleration of the main beam is close to the acceleration of the top surface of the support, so the acceleration of the support can be used to replace the acceleration of the main beam. Other factors do not play a controlling role.

[0071] S5: Using a nonlinear time history calculation method, the seismic response of the main beam is calculated. Based on the mapping relationship established in S4, the seismic displacement response of the track structure is evaluated, specifically including:

[0072] After considering the damage or fracture of the track structure, its impact on the seismic response of the bridge structure is much smaller than the error caused by the inaccurate value of the seismic load. Without considering the influence of the track structure, the seismic response of the bridge structure is more inclined to the vibration of the bridge itself, which leads to a greater difference in vibration between adjacent bridges and is more conducive to conservatively estimating the maximum seismic response of the track structure on the bridge.

[0073] A nonlinear time history calculation method for bridge structures with a simplified two-degree-of-freedom system is used, while considering the influence of uncertainties in bridge parameters, to quickly calculate the seismic response of the bridge structure and obtain its seismic response index.

[0074] Using the method of this embodiment and the finite element method for track-bridge systems, the same working conditions were calculated. The results showed that the seismic response calculated by the method of this invention was greater than that calculated by the finite element method. Therefore, this method can conservatively estimate the main seismic response of the track-bridge system, which is practical and efficient.

[0075] The seismic response indicators of bridges include the relative displacement at the beam ends and the acceleration of the main beam. Based on the aforementioned mapping relationship, the seismic displacement response of the track structure can be quickly estimated using the maximum relative displacement at the beam ends and the maximum acceleration of the main beam.

[0076] S6: Based on the mapping relationship established in S4, damage limits for the main components of the bridge structure are set, and seismic verification calculations are performed on the main components of the bridge structure to achieve seismic assessment of the track-bridge system. Specifically, this includes:

[0077] Based on the safety limits of track deformation under different damage levels and the deformation limits of related track structures calculated by existing post-earthquake bridge traffic simulation calculations, for different bridge types and track types, the limits of the obtained bridge seismic response indicators are calculated in reverse according to the mapping relationship, including but not limited to the relative displacement limits between the longitudinal and transverse beam ends, the acceleration limits of the main beam, etc.

[0078] In this embodiment, it is approximately assumed that the relative displacement between beam ends is approximately the same as the relative displacement between adjacent supports; therefore, the relative displacement limit of adjacent supports is used instead of the relative displacement limit of beam ends. Similarly, it is approximately assumed that the acceleration of the main beam is the same as the acceleration of the top surface of the supports; therefore, the acceleration limit of the top surface of the supports is used instead of the acceleration limit of the main beam. Based on the energy transfer relationship, the energy transferred from the pier to the supports must be less than the energy transferred from the earthquake to the pier; this is determined by the pier top drift ratio. ( Indicates the first The horizontal displacement of the pier top corresponding to each damage level The pier height is used to obtain the pier limit values ​​under different damage levels. The relative displacement limit between adjacent supports and the support acceleration limit are jointly determined by the pier's own damage and the seismic response limit of the main beam.

[0079] This embodiment also includes a readable storage medium storing computer program instructions that, when executed by a processor, implement the seismic assessment method for the track-bridge system as described above.

[0080] 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.

[0081] 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 perform the seismic assessment method for the track-bridge system as described above.

[0082] 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.

[0083] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for seismic evaluation of a track-bridge system, characterized by, The method comprises the following steps: S1: establishing a finite element model of a track-bridge system of a high-speed railway; S2: generating artificial seismic waves as seismic excitation of the track-bridge system according to a response spectrum, and performing nonlinear time-history analysis on the track-bridge system under different working conditions to obtain average values of seismic responses of the track structure under each working condition; S3: analyzing control factors of the seismic responses of the track structure under different working conditions according to the average values of the seismic responses of the track structure; S4: establishing a mapping relationship between the seismic responses of the track structure and seismic responses of main beams according to the control factors; S5: calculating the seismic responses of the main beams by using a nonlinear time-history calculation method, and evaluating the seismic displacement responses of the track structure according to the mapping relationship established in S4; S6: setting damage limits of main components of the bridge structure according to the mapping relationship established in S4, performing seismic checking calculation on the main components of the bridge structure, and realizing seismic evaluation of the track-bridge system; S2 specifically comprises: adjusting characteristic periods to generate artificial seismic waves in batches according to a target response spectrum; adjusting peak accelerations of each seismic wave as longitudinal and transverse seismic excitation to input the finite element model of the track-bridge system, and performing nonlinear time-history analysis on the track-bridge system under different working conditions to obtain average values of seismic responses of the track structure under each working condition; the different working conditions are divided according to support forms and beam end connection conditions of the track-bridge system; the control factors are specifically: when there is a gap between the main beams, the seismic responses of the track structure are controlled by relative displacements between the beam ends; when adjacent beam ends adopt a coupling beam device, the seismic responses of the track structure are controlled by main beam accelerations; S4 specifically comprises: quantitatively analyzing measuring indexes of the seismic responses of the main beams which may control the seismic responses of the track structure according to the control factors; performing regression analysis on the seismic responses of the track structure and the seismic responses of the main beams by using a mathematical method to obtain corresponding mapping relationships; the mapping relationships are specifically: for the track-bridge system which does not adopt the coupling beam device, the seismic responses of the track structure have a power function relationship with the relative displacements of the beam ends, and other factors do not play a control role; for the track-bridge system which adopts the coupling beam device, the seismic responses of the track structure have a linear relationship with the main beam accelerations, and other factors do not play a control role.

2. The method of claim 1, wherein, S1 specifically comprises: selecting the track-bridge system of the high-speed railway as a target object; concrete main beams in the track-bridge system are simulated by using elastic beam elements, and base plates, track plates and rails are simulated by using beam elements with tensile fracture; based on an OpenSEES platform, simulation elements used in bridge structures and track structures are integrated to establish a finite element model of the track-bridge system of the high-speed railway which takes into account material nonlinearity and constraint nonlinearity and can correctly simulate structural responses of the target object under seismic excitation.

3. The method of claim 1, wherein, S5 specifically comprises: using a nonlinear time-history calculation method of a bridge structure of a two-degree-of-freedom simplified system, considering influences of parameter uncertainties of the bridge structure, quickly calculating seismic responses of the bridge structure, and obtaining seismic response indexes of the bridge structure. The seismic response indexes of the bridge structure include a relative displacement of a beam end and an acceleration of a main beam, and according to the mapping relationship, the seismic displacement response of the track structure is quickly estimated through the maximum relative displacement of the beam end and the maximum acceleration of the main beam.

4. The method of claim 3, wherein, The S6 specifically includes: Based on the safety limit of the track deformation under different damage levels obtained from the existing post-earthquake bridge driving simulation calculation and the deformation limit of the related track structure, for different bridge types and track types, the limit of the obtained seismic response indexes of the bridge is inversely calculated according to the mapping relationship; The seismic response of the bridge pier, bearing and bridge is quickly calculated by using a nonlinear time-history calculation method of a two-degree-of-freedom simplified system of the bridge structure, whether the limit of the seismic response index is satisfied is judged, and the track structure response or post-earthquake driving performance is quickly evaluated.

5. A readable storage medium characterized by, The computer program instructions are stored on the computer readable storage medium, and when the computer program instructions are executed by the processor, the track-bridge system seismic evaluation method is realized.

6. An electronic device, comprising: The computer program instructions are stored on the computer readable storage medium, and when the computer program instructions are executed by the processor, the track-bridge system seismic evaluation method is realized. The computer program instructions are stored on the computer readable storage medium, and when the computer program instructions are executed by the processor, the track-bridge system seismic evaluation method is realized.

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