Vibrations induced by external loads play a critical role in the performance and safety of high-speed train bogies. Accurate knowledge of the dynamic forces acting on bogie frames is essential for predicting structural responses, enhancing numerical modelling and planning maintenance more effectively. This study aims to develop and evaluate a comprehensive model-based framework for predicting excitation forces on railway bogies, addressing the challenges posed by forces that are difficult or impossible to measure directly.

The proposed framework integrates multi-body dynamics (MBD) simulations, structural finite element (FE) modelling and machine learning (ML) to estimate the forces acting on the bogie frame of a high-speed train. Firstly, an MBD model of a Chinese high-speed train was established and validated against in-service measurement data, from which realistic time-domain loads acting on the bogie frame can be obtained. Separately, modal dynamic simulations of the bogie frame’s FE model were performed with stochastic loading to extract corresponding accelerations over a broad range of dynamic behaviour. These were employed to train an ML model to learn the inverse mapping from structural response to applied forces. For validation, the MBD-derived forces were applied to the FE model to obtain corresponding accelerations, which were then used to assess the ML model’s ability to reconstruct the original forces.

The approach can successfully predict nonlinear excitation forces acting on the bogie frame. Based on modal system responses to randomized force inputs, the entire parameter space can be represented, and the trained ML model demonstrates a strong capability to estimate dynamic loads from validated MBD simulations. Through appropriate training, the method exhibits robustness against noise and sensor placement and opens new opportunities for improving the analysis of track–vehicle interaction and the dynamic modelling of bogies. Research limitations/implications – The approach depends on the accuracy of the validated MBD and FE models, meaning modelling assumptions and simplifications may introduce errors in the predicted forces. High-fidelity in-service measurements are required for model validation but are not always available. Purely simulation-based models enable the prediction of forces and load distributions at the bogie, but the results are strongly model-dependent. Even if the models are validated against reference data, they only reflect an idealized operating condition, and uncertainties in measurement parameters, model parameters, damping behaviour or contact models can significantly affect the accuracy of force predictions.

This research introduces a novel, integrated framework for indirect bogie force estimation that enhances both modelling accuracy and practical diagnostic capability in railway engineering. By integrating numerical simulations, in-service measurements and ML, the study advances current methodologies for analysing high-speed railway vehicles. The approach offers valuable potential for refining vehicle models, guiding maintenance strategies and informing future research on data-driven structural force prediction.

The U-shaped rib-to-deck welded joint in orthotropic steel decks (OSDs) is prone to multiple fatigue cracks, which threaten structural integrity. Current design codes worldwide stipulate a minimum weld penetration rate of 75% or 80%, but practical challenges exist in meeting these requirements due to welding process limitations and machining errors. This study aims to investigate the influence of weld penetration rate on the fatigue performance of such joints, providing a theoretical basis for optimizing design and construction schemes.

Firstly, finite element models of U-shaped rib-to-deck welded joints with penetration rates of 65%, 75%, 85% and double-sided welds were established to analyze mechanical characteristics under typical loading conditions. Fatigue tests were then conducted on specimens with different penetration rates, and phased array ultrasonic testing technology was employed to assess penetration depth. Finally, fatigue S-N curves were regressed for partial penetration and double-side welded joints to quantify fatigue performance.

Stress concentration at the weld root decreases with the increase of penetration rate in partial penetration welds, while double-sided welds eliminate the weld root and further reduce stress concentration. Penetration depth exhibits significant dispersion even within the same weld. Partial penetration welds mainly initiate cracks from the weld root and propagate along the weld throat, whereas double-sided welds initiate cracks from the inner weld toe and propagate along the rib web. The fatigue strength of double-sided welds (143.9 MPa) is significantly superior to that of partial penetration welds (96.9 MPa) at 2×106 cycles.

This study fills the gap of limited experimental data on the fatigue performance difference between partial penetration and double-side rib-to-deck welded joints. The findings clarify the influence mechanism of penetration rate on fatigue behavior, providing valuable theoretical support and technical reference for the design optimization, construction quality control and maintenance decision-making of OSD welded joints.

This study systematically examines the potential for integrating crowd logistics (CL) with rail transport to enhance the efficiency, sustainability and multimodal performance of first and last-mile urban freight operations. It synthesizes the conceptual and empirical foundations of this emerging research area, identifies dominant scholarly trends and highlights gaps that constrain practical implementation of Rail-CL systems.

A systematic literature review was conducted following PRISMA 2020 guidelines. Fifty peer-reviewed publications from 2009 to 2025 were selected from major academic databases and evaluated using the 2018 Mixed Methods Appraisal Tool (MMAT). Extracted data covered study design, research aims, geographic scope, transport modes, technologies, sustainability outcomes, integration strategies and reported barriers. The evidence was synthesized using thematic and descriptive analysis.

The literature reveals a strong bias toward last-mile crowdshipping, with comparatively limited attention to first-mile operations and rail-based multimodal integration. Although environmental, economic and social benefits are frequently reported, most studies remain conceptual with limited real-world validation. Core challenges include regulatory uncertainty, inadequate rail-terminal infrastructure, coordination difficulties among stakeholders and persistent concerns regarding trust, liability and service reliability. Only a small number of studies propose integrated Rail and CL frameworks, confirming a substantial research gap.

This review offers the first comprehensive assessment of literature directly linking CL with rail freight transport. It establishes Rail and CL integration as an emerging research domain and outlines a forward-looking agenda focused on empirical testing, digital platform development and context-specific models particularly relevant for developing countries pursuing sustainable and resilient freight systems.

The expansion of the railway network and the increase in operation and maintenance intensity have rendered the durability, applicability and standardization of bridge guardrails key bottlenecks for ensuring personnel safety, improving the efficiency of maintenance windows, reducing the full life cycle cost, and promoting the high-quality development of railways. It is urgent to systematically sort out the domestic technological evolution, quantitatively evaluate the material performance, establish a full life cycle management framework, fill the gaps in the current standards regarding material selection, manufacturing and acceptance, and provide a scientific basis for the formulation of new standards.

(1) Literature and case study research - summarize the application characteristics and failure modes of steel, concrete, and fiber composite materials. (2) Material and process testing - measure the mechanical, corrosion resistance, and aging resistance properties of polyurethane pultruded composite materials. (3) Structural calculation - check the displacement of each railing post and handrail, and verify the safety margin. (4) Standard comparison - identify the gaps between domestic and international standards and the improvement paths.

Polyurethane railings are lightweight, high-strength, weather-resistant, maintenance-free, have minimal deformation and are suitable for coastal and cold regions. Steel railings corrode rapidly, are costly to repaint, and are difficult to maintain. Concrete is prone to cracking, frost peeling and rust expansion, and has a short lifespan. The current standards lack durability indicators, process control and full-life cycle evaluation, which restricts the promotion of new materials.

Establish polyurethane as the preferred option in complex environments; offer optimization directions for steel and concrete anti-corrosion structures; supplement durability indicators, process key points and cost models, and promote the standardization, lightweighting and long service life of ancillary facilities.

This paper presents a comprehensive systematic review of low-carbon solid waste materials applied in railway sub-ballast layers, aiming to critically assess their mechanical performance, durability, environmental benefits and regulatory readiness. The study addresses the growing need to decarbonize rail infrastructure while reducing dependence on natural aggregates, positioning sub-ballast as a strategic layer for circular economy implementation in ballasted track systems.

A PRISMA-based systematic review methodology was adopted to identify, screen and analyses peer-reviewed studies published between 2000 and 2025. The final database comprises experimental, numerical and field investigations covering mining residues, steel slags, construction and demolition waste, rubberized composites, alkali-activated materials and other industrial by-products applied to railway sub-ballast. Mechanical behavior under cyclic loading, resilient modulus, permanent deformation, hydraulic performance, durability and environmental indicators were extracted and synthesized. In parallel, an international regulatory analysis was conducted to compare sub-ballast specifications across Europe, North America, Asia-Pacific and Brazil, enabling identification of performance-regulation gaps and barriers to implementation.

The review demonstrates that several low-carbon waste-derived materials exhibit mechanical performance comparable to or exceeding that of conventional granular sub-ballast, particularly in terms of stiffness retention, resistance to permanent deformation and degradation under repeated loading. Steel slags, recycled concrete aggregates, slate waste and rubber-modified blends consistently show favorable resilient behavior and enhanced damping capacity, while certain mining residues and alkali-activated granular systems present promising strength and durability characteristics. Life-cycle evidence indicates substantial reductions in embodied carbon and natural aggregate consumption when these materials are adopted. However, current railway standards remain largely prescriptive and index-based, rarely incorporating cyclic performance criteria or carbon metrics, creating a structural disconnect between scientific evidence and regulatory acceptance. This gap significantly limits large-scale implementation despite growing technical maturity.

This study provides the first integrated synthesis focused exclusively on low-carbon solid waste materials for railway sub-ballast, combining mechanical performance, environmental assessment and international regulatory comparison within a unified analytical framework. By explicitly linking laboratory evidence to policy and standardization challenges, the paper advances performance-based pathways for sustainable railway substructure design. The findings offer actionable guidance for infrastructure managers, regulators and researchers seeking to accelerate the transition toward circular, low-carbon rail systems through sub-ballast innovation.

This paper presents an investigation of the innovative “Dual Configuration” management model implemented in China’s high-speed rail comprehensive inspection and test train initiative. Against the backdrop of continuous iteration in global railway technology, an evaluation is conducted of the advancements in organizational structure, resource allocation, and process standardization facilitated by this framework.

A systematic analysis is employed of multi-tiered collaborative mechanisms anchored in a matrix-based joint working group, complemented by a value-tree analytical method to quantify cost-benefit optimization across the full lifecycle of train assets. This integrated approach encompasses dynamic resource-scheduling protocols and comprehensive risk-control systems.

Results indicate the “Dual-Configuration” model achieves dual operational functionality within a unified platform, effectively compressing project duration and reducing lifecycle costs. Value tree analysis reveals multidimensional cost-saving mechanisms through platform sharing, consolidated maintenance systems, and parallel management processes. Field implementation validates that this model significantly enhances equipment utilization and mission responsiveness while supporting integrated Electric Multiple Unit (EMU) and inspection technologies.

Transferable management paradigms for high-speed rail system development and safety assurance are established in this research paper. The value-tree model provides a systematic framework for evaluating the economic benefits of dual-use platforms, offering quantitative decision-making support for complex infrastructure investments. Furthermore, concrete optimization strategies and cross-industry applications for the “Dual-Configuration” framework are proposed.

High-speed railway development in Vietnam requires an early assessment of wheel-rail degradation mechanisms. This study investigates wheel wear evolution and rolling contact fatigue (RCF) risk under representative high-speed operating conditions.

A numerical framework integrating multibody vehicle dynamics and wear prediction modelling is developed. Vehicle-track interaction is simulated in VI-Rail using a standard ERRI passenger bogie model. Key wheel-rail contact parameters, including normal forces, creepages and contact locations, are extracted and used in an Archard-based wear model to predict wheel profile evolution, while RCF risk is assessed using Hertzian contact stress indicators.

The results show that wheel wear alters tread geometry, with a maximum wear depth of approximately 0.2–0.4 mm, affecting vehicle dynamics. The critical speed varies non-monotonically, increasing by about 3–5% at early stages and decreasing by 10–15% with further wear. Track irregularities raise creepage to the order of 10?³ and increase wear rate by 20–30%. These effects also indicate an elevated risk of RCF.

The study provides a multibody dynamics-based framework for analysing wheel wear and RCF in prospective Vietnamese high-speed railway applications. The proposed framework also provides a scientific basis for assessing wheel degradation and supporting infrastructure design, operational planning and predictive maintenance in high-speed railway systems.

The study aims to analyze the relationship between seismic damage to various railway infrastructures and seismic intensity through historical seismic damage investigations of conventional railways, thereby addressing the issues of a lack of focus in post-earthquake inspections and prolonged train service restoration times after seismic events.

Post-earthquake railway inspection data were collected from 6 historical earthquakes in Xinjiang and 4 in the Sichuan-Yunnan region through field surveys and data research. Longitude and latitude coordinates of damaged sections were calculated according to their kilometer markers (K marks) and visualized on maps. The approximate seismic intensity at each damage site was estimated using intensity attenuation relationships or instrumental intensity data from adjacent stations, and empirical patterns of seismic damage modes were summarized.

Through investigations of historical seismic data and actual railway damage in Xinjiang and the Sichuan-Yunnan region, results indicate that in areas with seismic intensity greater than Level V (I > V), main structural damage to conventional railway infrastructure occurs. This includes cracking of bridge piers and abutments, differential settlement at bridge ends, track distortion, fracture of tunnel portals, and edge collapse, all of which disrupt train operations. In contrast, in areas with seismic intensity of Level Vor below (I 5 V), no records indicate that earthquakes caused main structural damage to conventional railway infrastructure. Only damage to ancillary facilities was observed, such as concrete spalling from girders, cracking of transverse diaphragms, damaged protective cones, deformed limiters, and cracks in subgrade slopes—none of which affect train passage.

Based on investigations into the post-earthquake infrastructure conditions of conventional-speed railways in earthquake-prone regions of China such as Xinjiang, Sichuan and Yunnan after 10 historical earthquakes, this study analyzed the correlation between seismic damage and corresponding seismic intensities using instrumental intensity data from surrounding seismic stations and intensity attenuation laws. A conclusion was drawn that train operation remains unaffected in areas with seismic intensity no higher than V (I 5 V). For the first time, this research established a correlation between post-earthquake damage to conventional-speed railways and seismic intensity, and identified the safety threshold at seismic intensity V. The findings enable railway personnel to conduct targeted post-earthquake inspections, significantly reduce inspection workload, and alleviate the pressure on post-earthquake operation recovery.