Search Results (67)

Cross-line operation and express–local train coordination are both crucial for enhancing the efficiency of multi-level urban rail transit systems. Most studies address suburban railway operations in isolation, overlooking coordination and inducing supply–demand mismatches that weaken system efficiency. This study addresses the joint optimization of cross-line operation and express–local scheduling by proposing a novel train timetable model. The model determines train service plans and departure times to minimize total system cost, including train operating and passenger travel costs. A space–time network represents integrated train–passenger interactions, and an extended adaptive large neighborhood search (E-ALNS) algorithm is developed to solve the model efficiently. Numerical experiments verify the effectiveness of the proposed approach. The E-ALNS achieves near-optimal solutions with less than 4% deviation from Gurobi. Comparative analysis shows that the proposed hybrid operation mode reduces total passenger travel cost by 6% and improves the cost efficiency ratio by 13% compared to independent operations. Sensitivity analyses further confirm the model’s robustness to variations in transfer walking time, passenger penalties, and waiting thresholds. This study provides a practical and scalable framework for optimizing train timetables in complex cross-line transit systems, offering insights for enhancing system coordination and passenger service quality. Full article

Periodic train timetables provide passengers with easily accessible rail transport services. However, in networked railway operations, some long-distance cross-line trains have high operational priority and pose difficulties for scheduling local services. In this paper, we address the minimal-cycle-length periodic train timetabling problem with high-priority cross-line operations and complex local train types. We propose a special set of constraints to accommodate the prespecified operational times of cross-line operations with regard to system robustness. As the cycle length is regarded as a decision variable, the formulation is nonlinear. To solve the problem, we exploit the connection between cycle length and consumed capacity of periodic timetables and propose high-level cycle-capacity and binary search-guided iterative solution frameworks, which implicitly enumerate the periodic train timetabling problems. Using the real-world operational data of the Guangzhou–Zhuhai Intercity Rail Line, we explore the solution performance of the proposed solution approaches and the straight linearization of the problem, and we also compare the practices of fixing prespecified operational times and our proposed constraints for the cross-line services. The results demonstrate that our proposed method can efficiently achieve flexible while recoverable operational times for the cross-line services and the proposed implicit enumeration algorithms significantly outperform the direct linearization, which increases the search space significantly due to the considerable dimensionality of the periodic decision variables involved. Numerical computations also suggest that our proposed constraints provide a type of approach for balancing the operational convenience and stability margins available in the periodic timetable with the presence of cross-line operations. Full article

Background: Physical, emotional, psychological, and social factors influence the high level of burden of a caregiver providing care for a patient at home after a stroke. The purpose of this study was to identify and evaluate factors influencing the high level of burden on the caregiver providing care for a post-stroke patient, including factors on the part of the patient and caregiver. Methods: This cross-sectional study was conducted at the Neurological Rehabilitation Department of the Hospital Beskid Treatment and Rehabilitation Complex in Jaworze, Poland, and the Neurological Rehabilitation Department of the Railway Hospital in Wilkowice-Bystra. The study participants comprised post-stroke patients and their family caregivers (during visits to hospital), 110 pairs. The measures for caregivers were such as the following: Beck Depression Inventory, the Polish adaptation of the Perceived Stress Scale, the Polish adaptation of the Mini-COPE questionnaire to measure stress coping strategies, and the WHO Quality of Life Brief Version. The measures for patients were such as the following: the modified Rankin Scale and Abbreviated Mental Test Score to assess functional capacity for simple Activities of Daily Living (ADL). All statistical calculations were performed using the R statistical package version 4.4.2. Results: A high caregiver burden was found in 30 people (27.3%). Logistic regression analysis proved that low quality of life, stress, caregiver-triggered strategies (discharge and cessation of activities), caregiver frustration, psychological burden, financial situation, longer time spent on patient care, functional status (ADL) on the part of the patient, judgment of significant degree of disability judgment, and age of the patient are determinants affecting high caregiver burden levels. Conclusions: Almost 1/3 of caregivers experienced a high burden when taking care of a person after stroke. Analyzing the Gini index, from the model’s point of view, quality of life is the most important characteristics, and caregiver frustration is the least important, which influences the high level of caregiver burden. Full article

The rapid development of urban transportation renovation and transportation networks in China has driven the construction of an increasing number of large-span, large cross-section tunnels under sensitive environments, such as airport runways, critical infrastructure, and high-speed railways. These projects often require strict settlement control within a millimeter-level tolerance range, thus theoretical methods and key technologies for micro-settlement control have been developed. This study first derives a calculation formula for surface settlement associated with large cross-section tunnels and elucidates its correlations with factors such as pipe-roof stiffness, support system stiffness, pipe-roof construction procedures, and groundwater level changes. Theoretical approaches for controlling micro-settlement are introduced, including increasing pipe-roof stiffness, reinforcing the support system, mitigating group pipe effects, maintaining pressure and reducing resistance around the pipe, and controlling groundwater levels. A method is proposed for determining the appropriate stiffness of the pipe roof and support system. The stiffness should be selected from the transition segment between the steep decline and the gentle slope on the stiffness-settlement curves of the pipe roof and the support system. If the stiffness of the pipe roof and primary support combined with temporary support fails to meet the micro-settlement control requirements, an integrated support system with greater stiffness can be adopted. A reasonable pressure-regulating grouting technique for maintaining pressure and reducing resistance around the pipe is proposed. It is recommended that the spacing for simultaneous jacking of pipes be greater than half the width of the settlement trough. For over-consolidation-sensitive strata such as medium or coarse sands, water-blocking measures, including freezing, grouting, or a combination of both, are recommended. For over-consolidation-insensitive strata like gravels and cobbles with strong permeability, water-blocking treatments are generally unnecessary. The proposed theoretical approaches have been successfully implemented in projects such as the tunnel beneath Beijing Capital Airport runways and Taiyuan Railway Station, demonstrating their reliability. The research findings provide valuable insights into surface micro-settlement control for similar projects. Full article

The European Union (EU) is paving the way toward “Vision Zero”, a future goal of eliminating road fatalities and severe injuries. Railway level crossings are critical safety hotspots where road and rail traffic intersect and present a unique challenge in balancing the safety of both rail and road users while ensuring efficient traffic flow. Collisions at these crossings account for a significant proportion of railway-related fatalities in the EU, underscoring the need for targeted safety interventions. This article explores the impact of signal preemption strategies on the safety and operational performance of railway level crossings through a microsimulation analysis. Using VISSIM, a railway level crossing and its adjacent road intersection were modeled under existing and alternative scenarios. The preemption strategy was designed to clear vehicles from the crossing area before train arrivals, reducing conflict risks and optimizing traffic flow. Key findings reveal that the proposed preemption strategy significantly reduces queue lengths within critical safety zones, mitigating vehicle spillback and enhancing operational efficiency. The analysis highlights the importance of integrating railway operations with traffic signal systems, particularly in urban areas with limited queue storage capacity. Full article

Track and preventive maintenance are necessary for the safe and comfortable operation of railways. Track displacement measured by track inspection vehicles or trolleys has been primarily used for track management. Thus, vibration data measured in in-service vehicles have not been extensively used for track management. In this study, we propose a new technique for estimating track irregularities from measured car body vibration for track management. The correlation between track irregularity and car body vibration was analysed using a multibody dynamics simulation of travelling rail vehicles. Gaussian process regression (GPR) was applied to the track irregularity and car body vibration data obtained from the simulation, and a method was proposed to estimate the track irregularities from the constructed regression model. The longitudinal-level, alignment, and cross-level irregularities were estimated from the measured car body vibrations and travelling speeds on a regional railway, and the results were compared with the actual track irregularity data. The results showed that the proposed method is applicable for track irregularity management in regional railways. Full article

This paper proposes a dual-parameter strain/displacement safety monitoring technology for railway tunnel lining structures. An integrated monitoring system with FBG (Fiber Bragg grating) and VDM (video displacement meter) components was used to monitor both the strain and deformation of the tunnel cross-section. Initially, a comprehensive experimental study was carried out using FBG strain sensors with temperature-compensated grating. The temperature-compensated grating was used to further improve the monitoring accuracy. The data show that the stability and accuracy were better than the traditional electronic strain sensor. Secondly, high-precision and multipoint monitoring of railway tunnel lining deformation was achieved by using VDM technology. Three months of case study results taken from the Gansu Railway Tunnel in China demonstrated a tunnel cross-section strain accuracy for microstrain and crown deformation at the submillimeter level, respectively. The technology provides a new high-precision way to monitor the condition of tunnel lining structures. Full article

Railway level crossings pose risks to both train passengers and road users, worsened by the complex interaction between rail and road traffic, particularly on local railways. This study introduces a Risk Management (RM) framework designed to enhance safety at level crossings on local railways by providing a decision-support tool. By individually assessing risk factors, the framework allows for a precise evaluation of the current risk levels in terms of both Cumulated and Individual Risk levels, Individual Risk, and the impacts of potential modifications. The framework allows the quantitative assessment of risk and resource optimization, enabling infrastructure managers to identify high-risk crossings and select the most effective safety interventions. The framework was applied to 96 level crossings on an Italian local railway line, demonstrating its ability to support decision-making for targeted interventions as well as broader network-level actions, significantly improving system safety. Full article

Due to its inherent advantages, shield tunnelling has become the primary construction method for urban tunnels, such as high-speed railway and metro tunnels. However, there are numerous technical challenges to shield tunnelling in complex geological conditions. Under the disturbance induced by shield tunnelling, sandy pebble soil is highly susceptible to ground loss and disturbance, which may subsequently lead to the risk of surface collapse. In this paper, large-diameter slurry shield tunnelling in sandy pebble soil is the engineering background. A combination of field monitoring and numerical simulation is employed to analyze tunnelling parameters, surface settlement, and deep soil horizontal displacement. The patterns of ground disturbance induced by shield tunnelling in sandy pebble soil are explored. The findings reveal that slurry pressure, shield thrust, and cutterhead torque exhibit a strong correlation during shield tunnelling. In silty clay sections, surface settlement values fluctuate significantly, while in sandy pebble soil, the settlement remains relatively stable. The longitudinal horizontal displacement of deep soil is significantly greater than the transverse horizontal displacement. In order to improve the surface settlement troughs obtained by numerical simulation, a cross-anisotropic constitutive model is used to account for the anisotropy of the soil. A sensitivity analysis of the cross-anisotropy parameter α was performed, revealing that as α increases, the maximum vertical displacement of the ground surface gradually decreases, but the rate of decrease slows down and tends to level off. Conversely, as the cross-anisotropy parameter α decreases, the width of the settlement trough narrows, improving the settlement trough profile. Full article

The high-quality development of the Yellow River Basin is still facing the issue of imbalance and inadequacy, and it urgently requires the backing and assistance of a well-coordinated and efficient comprehensive transportation network system. Based on this purpose, this study uses a composite system synergy degree model incorporating “mode dimension + regional dimension” to analyze the evolution of this network. The results indicate the following: (1) Railway and air transportation surpass highway transportation in growth and synergy, though overall system synergy is still low. (2) Downstream areas are gradually taking the lead, and the orderliness of each subsystem is gradually becoming consistent. The complexity and variability of the composite system’s synergy are high, with an overall low level of synergy. Overall, despite improvements in service capacity and quality, better integration of different transport modes and enhanced cross-regional cooperation are needed. This study reveals and analyzes in depth the complexity of the comprehensive transportation network system in the Yellow River Basin and its spatiotemporal characteristics of synergistic evolution. We propose suggestions for high-quality development at national, regional, and industry levels, fostering the continuous improvement of the system structure, which aids in overcoming the tangible obstacles faced by the high-quality development of the Yellow River Basin. Full article

Aiming at the problems of large capacity, narrow transverse width, large excitation, high safety level, and difficulty in accurately grasping the working state of the cable-stayed bridge for the long-span track, this research obtains the structural response data in real time by establishing a health monitoring system. The adaptive filtering method was employed to separate the train load response and the temperature load response. Then, a train load effect analysis method based on the influence line and a temperature load effect analysis method based on the correlation were proposed to assess the operational status of the bridge in real time and objectively. The Chongqing Nanjimen Railway Track Bridge (hereinafter Chongqing Nanjimen track bridge) project was utilized as a case study to demonstrate the application of these methods. The results show that the adaptive filtering method can effectively separate the response of train and temperature loads. The normalized cross-correlation (NCC) results of the measured train load response and the influence line’s finite element calculation show a high degree of fit between the measured values and the theory, proving that no significant anomalies are found in the bridge. There is a strong correlation between the ambient temperature difference and the Pearson correlation coefficient of structural response, which indicates that the Chongqing Nanjimen track bridge is currently in normal working condition. Full article

Beam bridges, as the primary structural form of medium and small-sized bridges, are extensively utilized for road and railway crossings over rivers and valleys. Ensuring their reliability during earthquakes is crucial not only for maintaining traffic flow but also for mitigating the seismic impact on the economy and society. Considering earthquake intensity and uncertain parameters, this paper proposes an innovative method for assessing the seismic reliability of simply-supported beam bridges under three different levels of seismic design: minor, moderate, and major earthquakes. The proposed method first estimates the probability of encountering three typical earthquake intensities during the design life of simply-supported beam bridges based on crowd intensity, benchmark intensity, and major earthquake intensity. It then introduces uncertain parameters and employs the point estimation method to calculate the probability of bridge passage under specific earthquake intensities. Finally, it combines these earthquake intensities to calculate the overall seismic reliability of simply-supported beam bridges. The effectiveness and efficiency of this method are demonstrated through calculations for a three-span, double-degree-of-freedom simply-supported beam bridge, and validated using Monte Carlo simulations. This research provides solid theoretical support for seismic assessment, design, and intensity-based reliability analysis of simply-supported beam bridges. Full article

DC railway electrification was deployed at the beginning of the 20th century in several countries in Europe. Today, this power system is no longer adapted to the demands of increased rail traffic. Due to the relatively low voltage level, the current consumed by the trains reaches several kAs. So, in the worst case, the locomotives cannot operate at their rated power due to the voltage drop along the contact line. Conventional solutions to reduce the voltage drop consist of increasing the cross-section of overhead lines or reducing the length of sectors by installing additional substations. Nevertheless, these solutions are expensive and not always feasible. The implementation of a Modular Battery Energy Storage System (MBESS) can be an alternative solution to reinforce the railway power supply. This paper first presents an MBESS based on elementary blocks associating Full-SiC Isolated DC-DC converter and battery racks. The electrical models of a railway sector and an elementary block are described, and simulations are performed considering real railroad traffic on two sectors of the French National Rail Network, electrified at 1.5 kV. The results show that the installation of an MBESS in the railway sector boosts the locomotive’s voltage while also increasing overall system efficiency. Full article

In the near future, there will be a greater emphasis on sharing network resources between roads and railways to improve transportation efficiency and reduce infrastructure costs. This could enable the development of global Cooperative Intelligent Transport Systems (C-ITSs). In this paper, a software-defined networking (SDN)-based common emergency service is developed and validated for a railway and road telecommunication shared infrastructure. Along with this, the developed application is capable of reducing the chances of distributed denial-of-service (DDoS) situations. A level-crossing scenario is considered to demonstrate the developed solution where railway tracks are perpendicular to the roads. Two cases are considered to validate and analyze the developed SDN application for common emergency scenarios. In case 1, no cross-communication is available between the road and railway domains. In this case, emergency message distribution is carried out by the assigned emergency servers with the help of the SDN controller. In case 2, nodes (cars and trains) are defined with two wireless interfaces, and one interface is reserved for emergency data communication. To add the DDoS resiliency to the developed system the messaging behavior of each node is observed and if an abnormality is detected, packets are dropped to avoid malicious activity. Full article

The construction and expansion of high-speed railway networks in China has been occurring at a fast pace, resulting in some lines crossing through coal mine goaf sites. However, the embankment and train loads may trigger the activation of the coal mine goaf ground, posing a threat to traffic safety. To ensure the safety of construction and railway lines, an evaluation model on the activation classification of coal mine goaf ground, taking into account the high-speed railway load, is proposed, which is mainly applicable for middle–deep and level goaf areas using a longwall mining method. Firstly, 12 influencing factors are selected as the underlying evaluation indexes, and the catastrophe progression method model for evaluating the coal mine goaf ground stability is constructed. The findings of the evaluation were found to align with the actual results, indicating the reliability of the model. Then, the additional stress calculation model for high-speed railway ground with different embankment heights, train speeds, and axle loads was established, and the train load disturbance depth with a 5% criterion was determined. The influence degree of load on high-speed railway was divided, and the weight of each factor was determined. Finally, the extension comprehensive evaluation method was used to unite the stability grade of the coal mine goaf site and the influence degree of the train, so the evaluation model on activation classification was proposed. The accurateness and reliability of the proposed model was verified using the Taijiao high-speed railway cases and the model test. Full article