High-speed Railway Research Articles

Dynamic Modeling and Application of a Vehicle-Track-Bridge System Subjected to Track Alignment for High-Speed Railways

Dynamic Modeling and Application of a Vehicle-Track-Bridge System Subjected to Track Alignment for High-Speed Railways

Parametric modeling and engineering application of the high-speed continuous beam bridge based on Building Information Modeling.

To improve the informatization and intelligence level of high-speed railway (HSR) bridge construction, a parametric modeling method for continuous beam bridges based on Building Information Modeling (BIM) is proposed in this study. By this method, the parametric families of continuous beam components and key construction machinery are established, and the rapid modeling of overall continuous beam bridge and the simulation of critical construction process are realized as well. Taking the Caoxian-Shangqiu bridge of Xiong'an-Shangqiu HSR as a case study, the parametric modeling method is applied to conduct the engineering application on the prestressed duct layout and rebar clash detection. The results indicate that the modeling efficiencies of HSR continuous beam bridge and construction machinery are significantly increased by the established parametric modeling method. Based on the BIM model of continuous beam bridge, the improvement in the precision of prestressed duct layout and the elimination of rebar clash points can be achieved. The research achievement can guide the visualization of construction disclosure, enhance construction efficiency, and provide reference and technical support for the construction management and control of HSR continuous beam bridges.

Application of PS-InSAR and Diagnostic Train Measurement Techniques for Monitoring Subsidence in High-Speed Railway in Konya, Türkiye

Large-scale man-made linear structures like high-speed railway lines have become increasingly important in modern life as a faster and more comfortable transportation option. Subsidence or longitudinal levelling deformation problems along these railway lines can prevent the line from operating effectively and, in some cases, require speed reduction, continuous maintenance or repairs. In this study, the longitudinal levelling deformation of the high-speed railway line passing through Konya province (Central Turkey) was analyzed for the first time using the Persistent Scatter Synthetic Aperture Radar Interferometry (PS-InSAR) technique in conjunction with diagnostic train measurements, and the correlation values between them were found. In order to monitor potential levelling deformation along the railway line, medium-resolution, free-of-charge C-band Sentinel-1 (S-1) data and high-resolution, but paid, X-band Cosmo-SkyMed (CSK) Synthetic Aperture Radar (SAR) data were analyzed from the diagnostic train and reports received from the relevant maintenance department. Comparison analyses of the results obtained from the diagnostic train and radar measurements were carried out for three regions with different deformation scenarios, selected from a 30 km railway line within the whole analysis area. PS-InSAR measurements indicated subsidence events of up to 40 mm/year along the railway through the alluvial sediments of the Konya basin, which showed good agreement with the diagnostic train. This indicates that the levelling deformation of the railway and its surroundings can be monitored efficiently, rapidly and cost-effectively using the InSAR technique.

Integrated train timetable with supply–demand interactions at the Chinese high-speed railway

In traditional Chinese railway operations, train timetable and unit assignment are usually separated from pricing and seat allocation, resulting in a decrease in revenue and an increase in operating costs. In this paper, we study the integrated problem of train timetable, unit assignment, pricing, and seat allocation, where passenger choice behavior is modeled by the multinomial logit (MNL) model. This integration enables us to explicitly capture supply–demand interactions. The problem is formulated as a mixed integer nonlinear programming model with the objective of maximizing total profit. By converting the MNL model into its equivalent convex form, we recast the model as a tractable reformulation, allowing the use of a general-purpose solver to solve practical-sized instances. Based on real data from high-speed railway lines in China, three sets of case studies are conducted to validate the effectiveness and efficiency of the proposed approach.

Influence of pier height and ground motion parameters on seismic response and energy dissipation of isolated railway bridges

The overlap between high-speed railways and earthquake areas makes it necessary to implement isolation design for railway bridges. At present, the variation of seismic energy of railway bridges with structural and ground motion parameters is not clear. In this paper, the finite element models of railway bridges with different pier heights are established and verified by shaking table tests. Then, the nonlinear time history analysis of isolated and non-isolated models is carried out, and the differences in seismic response and energy dissipation between the two models under different parameters are compared. Finally, the isolation effect of hyperbolic friction pendulum bearing (HFPB) is evaluated by using the efficacy coefficient method. Results demonstrate that HFPB can not only reduce the seismic response of the girder and the pier, but also effectively reduce the seismic input energy, structural damping energy, and pier hysteretic energy. In addition, HFPB has a better seismic isolation effect when pier height is 3–15 m, site characteristic period is 0.25–0.45 s, and earthquake PGA is 0.2–0.5 g.

Study on damage of CRTS II slab tracks in coated-uncoated transition zones subjected to temperature and train loads

The CRTS II ballastless track is sensitive to temperature due to its longitudinal continuity. The application of reflective insulation coating can efficiently lower the temperature of the track slab, thereby decelerating track deterioration. Given the considerable length of high-speed railway lines, the application of reflective insulation coatings leads to numerous transitions between coated and uncoated sections. This study investigates the influence of reflective insulation coatings on the structural damage of coated-uncoated transition zones in railways. To this end, a CRTS II slab track model involving the bilinear cohesive zone model and the concrete plastic damage model is established. The model examines the combined impact of high temperature and train loading, aiming to investigate the damage patterns within the coated-uncoated transition zone of the track. The results indicate: (1) During high temperature loading, the center of the track slab layer is predisposed to warping compared to the sides. (2) If the cohesion parameter falls below 0.04 MPa, augmenting the cohesion model parameter effectively alleviates track slab arching. (3) In instances where the track slab lacks complete coverage of reflective insulation coatings, train loading may shift the location of the maximum vertical displacement and interface failure mode.

Research on Train-Induced Vibration of High-Speed Railway Station with Different Structural Forms.

Elevated stations are integral components of urban rail transit systems, significantly impacting passengers' travel experience and the operational efficiency of the transportation system. However, current elevated station designs often do not sufficiently consider the structural dynamic response under various operating conditions. This oversight can limit the operational efficiency of the stations and pose potential safety hazards. Addressing this issue, this study establishes a vehicle-bridge-station spatial coupling vibration simulation model utilizing the self-developed software GSAP V1.0, focusing on integrated station-bridge and combined station-bridge elevated station designs. The simulation results are meticulously compared with field data to ensure the fidelity of the model. Analyzing the dynamic response of the station in relation to train parameters reveals significant insights. Notably, under similar travel conditions, integrated stations exhibit lower vertical acceleration in the rail-bearing layer compared to combined stations, while the vertical acceleration patterns at the platform and hall layers demonstrate contrasting behaviors. At lower speeds, the vertical acceleration at the station concourse level is comparable for both station types, yet integrated stations exhibit notably higher platform-level acceleration. Conversely, under high-speed conditions, integrated stations show increased vertical acceleration at the platform and hall levels compared to combined stations, particularly under unloaded double-line working conditions, indicating a superior dynamic performance of combined stations in complex operational scenarios. However, challenges such as increased station height due to bridge box girder maintenance, track layer waterproofing, and track girder support maintenance exist for combined stations, warranting comprehensive evaluation for station selection. Further analysis of integrated station-bridge structures reveals that adjustments in the floor slab thickness at the rail-bearing and platform levels significantly reduce dynamic responses, whereas increasing the rail beam height notably diminishes displacement responses. Conversely, alterations in the waiting hall floor slab thickness and frame column cross-sections exhibit a minimal impact on the station dynamics. Overall, optimizing structural dimensions can effectively mitigate dynamic responses, offering valuable insights for station design and operation.

A ‘node-place-network-city’ framework to examine HSR station area development dynamics: Station typologies and development strategies

High-speed railway (HSR) stations play an important role in shaping the development/redevelopment of the surrounding areas. While different studies have been conducted to explore station area development, they tend to simplify the conceptualisation of station area development and lack a comprehensive perspective that captures how different variables at multiple levels are interacted with station area development. This research proposes the ‘node-place-network-city’ framework, an innovative extension of the traditional ‘node-place’ model, to analyse station area development. Focusing on 123 HSR station areas in the Yangtze River Delta as of 2018, this research employs spatial big data to explore the intricate relationships between various city and network indicators and station area development. Unlike previous studies that have typically simplified station area development and treated the relationships as linear, this study adopts a decision tree model. This method effectively identifies diverse typologies of HSR stations and facilitates the formulation of tailored development strategies for each type. This research significantly contributes to the theoretical understanding of HSR station area development and provides valuable and actionable insights for urban planners and policymakers. It marks a step forward in comprehensively assessing and guiding the development of HSR station areas, thereby offering a robust framework for both academic research and practical application in spatial planning.

Investigation of temperature field variations induced by the air thermodynamic behavior when trains pass through a high-speed railway tunnel in cold regions

High-speed railway tunnels in the cold region, whose numbers are increasing, are widely exposed to the threat of frost damage caused by extremely negative temperatures. The operation of high-speed trains has made this problem even more pronounced. But there are fewer studies focusing on the dynamic changes in temperature during train operation. In this paper, the air thermodynamic behavior of trains passing through a tunnel and its consequences were investigated with the help of the CFD method. In numerical simulations, conditions of different natural airflows, different train speeds, different blockage ratios, as well as two trains intersecting in the tunnel were involved. The following valuable results were obtained. In cold environments, train-induced pressure wave effects will affect the air thermodynamic behavior, but the overall trend in air temperature is mainly influenced by the heat transfer between cold and warm air. The high-speed train will lead to massive cold air being carried into the tunnel and some warm air inside being pushed out. Heat transfer between cold and warm air will cause a significant decrease in tunnel air temperature. This air thermodynamic behavior is particularly prominent in the case of large blockage ratios. When there are same-direction natural airflows, they will be coupled with train-induced airflows, causing a greater decrease in tunnel air temperature. In contrast, opposite-direction natural airflows can reduce the negative effects of the train. Taking the case of opposite-direction natural airflow velocity of 5 m/s as an example, the temperature changes of the three cross-sections are only 16.7 %, 14.8 %, and 42.1 % of those in the case of no natural airflow. Whatever the direction of natural airflows, coupling effects between them and train-induced airflows will be more significant as the natural airflow speed increases. Greater train speed means more cold air entering the tunnel and stronger heat transfer between cold and warm air, causing a more significant temperature decrease. When two trains intersect through the tunnel, airflows caused by them will be coupled. As a result, only a little air enters the tunnel from the entrance and exit, and the heat transfer between air with different temperatures is weak. In this case, the air temperature doesn't decrease but slightly increases as the air is compressed.

High-speed railways reduces carbon emissions: mediating effects of green innovation and the resilience of environmental investment

High-speed rails (HSRs) are a sustainable approach in many cities. Although some studies recognize that introducing HSR is negatively related to carbon emissions, explorations of the mechanisms underlying this relationship remain scarce. The main purpose of this study is to investigate whether introducing HSR reduces carbon emissions through increasing green innovation (GI) and the resilience of environmental investment (REI). Employing signal theory and fault tolerance theory, among others, we propose models that illuminate how inaugurating HSRs reduces carbon emissions through GI and REI. Our proposed central hypothesis is that GI and REI mediate carbon emission reduction by introducing HSR. In this study, we used the data from 284 China’s cities during 2000-2021 and examined our hypothesis via a difference-in-differences (DID) model. The results show that introducing HSR reduces carbon emissions through GI and REI. On the basis of the current status of China’s economic and social development, we further analyze several critical moderating effects, such as the digital economy, the urban‒rural gap, and whether it is a resource-based city. In 2023, China’s Central Economic Work Conference (CEWC) explicitly proposed “developing the digital economy.” We find that the digital economy strengthens the negative relationship between introducing HSRs and carbon emissions. The digital economy also strengthens the positive correlation between the introduction of HSR and GI. Additionally, this strengthens the positive correlation between HSRs and REI. In addition, the urban‒rural disparity is a manifestation of China’s uneven development. We find that the urban‒rural disparity weakens the relationship between HSRs and carbon emissions. In addition, China’s resource-based cities lag behind other cities. Our findings suggest that, in contrast to other cities, high-speed rails increase carbon emissions in resource-based cities.

Impact of high-speed railway network improvement on consumption synergy in Beijing-Tianjin-Hebei region

This paper investigates the impact of high-speed rail (HSR) network improvement on the consumption synergy of the Beijing-Tianjin-Hebei region by using the panel data of 13 prefectural-level cities from 2006 to 2021. The results show that: (1) The improvement of the HSR network in the Beijing-Tianjin-Hebei region has a significant positive impact on raising overall regional consumption levels. (2) The HSR network improvement has a heterogeneous impact on consumption in different cities within the Beijing-Tianjin-Hebei region. (3) The promotional effect on peripheral cities is greater than on central cities, thereby promoting the coordinated consumption development of the Beijing-Tianjin-Hebei region. The findings of this study have important policy implications, confirming that the construction of the HSR network can narrow the consumption gap within the region and promote consumption synergy across the region.

Fatigue life assessment of thermite welded rails based on laboratory tests and field measurement data

This in-depth study assesses the fatigue life of thermite-welded 60E1 rails by combining fatigue experimental tests with field measurement data. Material characterization, conducted using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), and Scanning Electron Microscopy (SEM), aimed to understand the fatigue behavior of these materials. The research was particularly focused on high-speed rail lines in South Korea, targeting areas with influence of track condition to collect strain data. By combining dynamic modulus calculations from high-speed tensile tests with the rain flow counting method for determining wheel loads, and employing the Linear Cumulative Damage method for estimating rail fatigue life, this study provides novel insights into the maintenance and durability of thermite welded rails. The integration of detailed laboratory experiments with field stress data offers a significant contribution to the predictive maintenance and lifecycle management of high-speed railway infrastructure.

Research on the Calculation Method and Influence Law of High-speed Railway Line Sound Source Propagation Attenuation Caused by Building Sheltering

Abstract In recent years, China’s rail transit system, particularly the high-speed railway network, has experienced rapid development. However, the issue of noise pollution along these railways has become increasingly severe. The accurate prediction of sound levels at specific points near buildings is challenging due to complex factors such as differences in line height, distance, and angle relative to the building. To address this challenge and improve predictions of sound propagation attenuation caused by building shelter from high-speed railway line sources, this study derives an integral expression for diffraction attenuation based on Curze and Meakawa’s point source acoustic diffraction theory. Numerical calculations are conducted to investigate the sound propagation attenuation patterns under different position relationships between buildings and railway lines. Field tests are also carried out along a high-speed railway in China. The findings are as follows: (1) The calculated results show a difference of less than 0.5 dB compared to measured values, indicating that they accurately reflect sound attenuation caused by building shelter. (2) The angle between the building and the railway as well as the distance between the sound point and the edge of the building significantly influence building shelter attenuation; with angle being most prominent among them within a frequency band of 500~2000 Hz resulting in an attenuation range of 0.6~15 dB variation should be considered when predicting noise levels at sensitive points or designing vibration and noise reduction measures accordingly. (3) Different distances between buildings and railway lines result in additional effects on attenuations.

A sensitive wavelength-enhanced reconstruction algorithm for track quality assessment based on measured data and vehicle dynamics

High-speed railways are extensively utilized worldwide. However, with prolonged operation, track irregularities increasingly pose significant challenges, adversely affecting the safety and stability of train operations. This paper proposes a sensitive wavelength-enhanced reconstruction algorithm based on the cmplete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) method to address this issue. This method evaluates the influence of reconstructed track irregularities on vehicle dynamic response, considering sensitive wavelengths and amplification factors. The algorithm effectively enhances these sensitive wavelengths while maintaining the integrity of the input signal, utilizing measured track irregularities. After applying the algorithm, the maximum vertical body acceleration rises by 206.09%. The study validates a coupled train model and analyzes the mapping relationship between single-wave irregularities and vertical body acceleration. Compared to random irregularities, the maximum vertical acceleration can amplify up to 122.80% under various operating conditions. The periodic sensitive wavelengths of track irregularities significantly impact the train’s dynamic response.

Effect of opening high-speed railway on family travel consumption

This study investigates the relationship between the opening of a high-speed railroad and family tourism consumption. It empirically finds that the opening of a high-speed railroad can promote family tourism consumption. Specifically, such high-speed railroad opening has varying impacts on the tourism consumption of (1) families with varying income levels, (2) urban and rural families, and (3) families with different education levels.

Dynamic response of high-speed railway vehicle and welded turnout on large-span bridges based on rigid-flexible coupling system

Welded Turnout on Large-span Bridge (WTLB) is a complex multi-layer heterogeneous system and can significantly influence the service performance of High-Speed Railway (HSR). Understanding the coupling dynamic response of the vehicle and WTLB is essential. Previous research did not consider the dynamic behavior of foundations, leading to an underestimation of the vehicle-turnout-foundation coupling dynamic response, particularly when turnouts were laid on large-span bridges. This study proposes a novel modeling method that includes the foundations, to overcome the previous shortcomings by applying a rigid-flexible coupling system. In this approach, the vehicle was modeled as a rigid body sub-model in a Multi-Body Software (MBS), while WTLB was modeled as a flexible bodies sub-model using Finite Element (FE) software. The modal information from the FE model was imported into the MBS software. The two sub-models were coupled by the wheel-rail contact in the MBS environment and then the Vehicle-turnout-bridge Rigid-flexible Coupling Dynamic (VRCD) calculation model was established and it was discovered that the calculation results showed good agreement with the field test data. Through the VRCD model, the safety of the structure, the stability of the vehicle and the comfort of passengers were investigated, as well as several important infrastructure factors. The results demonstrate that this novel method provides accurate calculations and highlights the complex and significant interactions in the vehicle-turnout-bridge system.

Defect Diagnosis for Autotransformer Winding in High-Speed Railway Based on Transfer Function Pole Distribution

Defect Diagnosis for Autotransformer Winding in High-Speed Railway Based on Transfer Function Pole Distribution

Review of Perspectives on Pantograph-Catenary Interaction Research for High-Speed Railways Operating at 400 Km/h and Above

Review of Perspectives on Pantograph-Catenary Interaction Research for High-Speed Railways Operating at 400 Km/h and Above

Investigation of the Variation in Insertion Loss of Vertical Noise Barriers for High-speed Railways at Different Levels of Sound Transmission Loss

Abstract The present study investigates the impact of sound transmission loss of vertical noise barriers for high-speed railways on insertion loss at various speed grades and heights. The findings reveal an initial increase in insertion loss followed by a plateau as sound transmission loss improves. A threshold value exists for weighted sound transmission loss, beyond which the insertion loss remains relatively constant. This threshold referred to as the minimum weighted sound transmission loss decreases with increasing train speeds and increases with higher noise barrier heights. The variation in insertion loss was calculated for noise barriers at heights of 2m and 3m under different sound transmission loss conditions, using measured sound source data corresponding to train speeds of 150km/h, 200km/h, 250km/h, 300km/h, and 350km/h. By polynomial fitting, at a train speed of 400 km/h, the minimum weighted sound transmission loss for 2m and 3m high noise barriers are determined to be 20dB and 21dB respectively.

Analysis of train-induced aerodynamic characteristics and pressure-relief measures relating to fully enclosed noise barriers installed on railway bridges

Fully enclosed noise barriers (FENBs) are increasingly being installed on high-speed railway bridges for noise pollution control. However, the aerodynamic effects of high-speed trains passing FENBs have an adverse impact on barrier durability and generate micro-pressure waves. In this paper, a numerical model of a train passing an FENB on a bridge is established. The aerodynamic pressure distribution along the FENB is analyzed for both a single train and two trains passing one another. The propagation characteristics and evolution mechanisms of pressure waves are then investigated. The results show that the pressure is lower at the ends of the FENB and higher in the middle along the direction of train travel. The peak positive and negative pressures at the mid-span are 1.95 and 4.47 times higher than those at the ends, respectively. This distribution is caused by the propagation, superposition, reflection, and attenuation of pressure waves. Compression waves account for 78.9% of the peak positive pressure. An amplification factor must be considered when estimating the impact of two trains passing one another. Analysis of five pressure-relief schemes shows that arranging a single pressure-relief hole at a high-pressure location effectively alleviates the over-pressure in the FENB. The overall pressure-relief effect is an exponential function of the single opening area. Considering a constant opening area, arranging several relief holes at equal spacing optimizes the adverse pressure distribution compared with the single-hole relief scheme. The equivalent forces of the multi-hole scheme are 3.35% and 7.58% lower than in the single-hole scheme.