Running test on high-speed railway track-simply supported girder bridge systems under seismic action

Bearing effects have not been deeply investigated in the dynamic analysis of a train-bridge coupled system subjected to earthquake motions, and existing studies on base isolation of railway bridges have typically not considered the running train. To fill these gaps, this paper develops the numerical model of a three-dimensional train-wheel-bridge-bearing (TWBB) system for seismic analysis. The substructuring method is implemented to separate the TWBB system into the train, wheel-rail, bridge and bearing subsystems, and couple them using state-space representations. The complete model of the TWBB system has three main features: fewer degrees of freedom (DOF) than traditional finite element methods, applicability to different types of bearings, and simplicity as no iterations in the simulation are required. Therefore, the proposed procedure demonstrates that the TWBB model is an efficient and flexible representation to obtain and predict realistic demands for engineering purposes.

Section: Introductionmentioning

confidence: 99%

Seismic analysis of 3D train–wheel–bridge–bearing systems: Modeling

Gómez

et al. 2023

“…We have discussed previously 1 that studies of railway systems subjected to earthquake motions were focused mainly on two considerations: (1) seismic analysis of systems where the effects of the bearings are ignored or highly simplified, [2][3][4][5][6][7] and (2) base isolation of railway bridges where the running train is not considered. [8][9][10][11][12] Despite that, several studies using simplified train-bridge-bearing system models have been able to provide an understanding of the bearings' effects.…”

Section: Introductionmentioning

confidence: 99%

Seismic analysis of 3D train–wheel–bridge–bearing systems: Illustrative examples

Gómez

et al. 2023

This paper presents numerical studies using the model of the three‐dimensional train–wheel–bridge–bearing (TWBB) system. The system responses under train‐induced excitation only, earthquake excitation only, and combined train‐induced plus earthquake excitation are evaluated in terms of structural safety, running safety, and ride comfort. By coupling the subsystem models, these numerical simulations require just seconds to execute, exhibiting high computational efficiency. Based on the simulation results, the main conclusion is that although the bearings may reduce the seismic bridge responses, they also are likely to deteriorate the train's running safety and ride comfort. Therefore, there is a requirement in future bearings design procedures for railway bridges to find a balance between the bridge and train seismic responses.

“…China witnessed the fast growth of HSR and the all-around construction of HSR networks in its central and eastern regions. [1][2][3] It was reported that China's HSR operating mileage has exceeded 40,000 km by the end of 2021. 4 Currently, China's HSR network layout is gradually extending towards its western provinces.…”

Section: Introductionmentioning

confidence: 99%

“…In August 2008, China opened its first HSR Beijing–Tianjin Intercity Railway. China witnessed the fast growth of HSR and the all‐around construction of HSR networks in its central and eastern regions 1–3 . It was reported that China's HSR operating mileage has exceeded 40,000 km by the end of 2021 4 .…”

Section: Introductionmentioning

confidence: 99%

Response spectra of fitted post‐seismic residual track irregularity for high‐speed railway

Zhou

Jiang

2022

Self Cite

Chinese high‐speed railway (HSR) network construction has expanded into earthquake‐prone areas. In this context, analyses of post‐seismic residual track irregularity and post‐seismic train speed threshold are vital. With a HSR bridge with track system taken as the study object, time‐domain signal for target post‐seismic residual track irregularity was constructed based on the Gaussian pulse translation theory. The response spectra of fitted post‐seismic residual track irregularity applicable to stochastic structures were established, thus providing irregularity input for ascertaining post‐seismic speed threshold. The results show that residual alignment irregularity has a large amplitude under transverse seismic actions; by contrast, cross‐level, gauge, and vertical irregularities showed small amplitudes. The evolution power spectral density (EPSD) of the stochastic post‐seismic residual track irregularities obeys a definite distribution in any frequency‐space coordinate. A uniquely deterministic target post‐seismic residual track irregularity can be constructed based on the stochastic irregularity set, and its safety guarantee rate can be precisely controlled by varying the significance level. Taking the first‐order transverse natural vibration period as the x‐axis and the amplitude of fitted post‐seismic residual track irregularity as the y‐axis, the response spectra of fitted post‐seismic residual track irregularity can be created. The irregularity response spectra are applicable to stochastic structures.