Search Results (199)

It is well known that there is a significant conflict of interest between high-speed rail (HSR) operators and logistics companies. This study proposes an HSR freight pricing strategy based on a multi-objective optimization framework and a freight mode splitting model based on the Logit model. A utility function was constructed to quantify the comprehensive utility of different modes of transportation by integrating five key influencing factors: economy, speed, convenience, stability, and environmental sustainability. A bi-objective optimization model was developed to balance the cost of the logistics with the benefits of high-speed rail operators to achieve a win–win situation. The model is solved by the TOPSIS method, and its effectiveness is verified by the freight case of the Zhengzhou–Chongqing high-speed railway in China. The results of this study showed that (1) HSR has advantages in medium-distance freight transportation; (2) increasing government subsidies can help improve the market competitiveness of high-speed rail in freight transportation. This research provides theoretical foundations and methodological support for optimizing HSR freight pricing mechanisms and improving multimodal transport efficiency. Full article

With China’s high-speed rail network undergoing rapid expansion, turnouts constitute critical elements whose safety and stability are essential to railway operation. At present, the efficiency of wheel–rail force safety monitoring conducted in the small hours reserved for the construction and maintenance of operating lines without marking train operation lines is relatively low. To enhance the efficiency of turnout safety monitoring, in this study, a three-dimensional BIM model of the No. 42 turnout was established and a corresponding wheel–rail force monitoring scheme was devised. Collision detection for monitoring equipment placement and construction process simulation was conducted using Navisworks, such that the rationality of cable routing and the precision of construction sequence alignment were improved. A train wheel–rail force analysis program was developed in MATLAB R2022b to perform signal filtering, and static calibration was applied to calculate key safety evaluation indices—namely, the coefficient of derailment and the rate of wheel load reduction—which were subsequently analyzed. The safety of the No. 42 turnout and the effectiveness of the proposed monitoring scheme were validated, theoretical support was provided for train operational safety and turnout maintenance, and technical guidance was offered for whole-life-cycle management and green, sustainable development of railway infrastructure. Full article

The stochastic fluctuation characteristics of wind speed can significantly affect the control performance of train suspension systems. To enhance the running quality of trains in non-stationary wind fields, this paper proposes a semi-active control method for trains based on fuzzy rules of non-stationary wind fields. Firstly, a dynamic model of the train and suspension system was established based on the CRH2 (China Railway High-Speed 2) high-speed train and magnetorheological dampers. Then, using frequency–time transformation technology, the non-stationary wind load excitation and train response patterns under 36 common operating conditions were calculated. Finally, by analyzing the response patterns of the train under different operating conditions, a comprehensive control rule table for the semi-active suspension system of the train under non-stationary wind fields was established, and a fuzzy controller suitable for non-stationary wind fields was designed. To verify the effectiveness of the proposed method, the running smoothness of the train was analyzed using a train-semi-active suspension system co-simulation model based on real wind speed data from the Lanzhou–Xinjiang railway line. The results demonstrate that the proposed method significantly improves the running quality of the train. Specifically, when the wind speed reaches 20 m/s and the train speed reaches 200 km/h, the lateral Sperling index is increased by 46.4% compared to the optimal standard index, and the vertical Sperling index is increased by 71.6% compared to the optimal standard index. Full article

In high-speed railway networks, multiple spatiotemporal correlated disruptions often cause passenger trip failures and delay propagation. Conventional single-disruption rescheduling strategies struggle to resolve such cross-line conflicts, necessitating an integrated, passenger-centric rescheduling framework for multiple correlated disruptions. This paper proposes a mixed-integer linear programming (MILP) model to minimize total passenger delay time and trip failures under scenarios involving disruptions that are geographically dispersed but operationally interconnected. Two rescheduling mechanisms are introduced: a stepwise rescheduling method, which iteratively applies single-disruption models to optimize local problems, and an integrated rescheduling method, which simultaneously considers the global impact of all disruptions. Case studies on a real-world China’s high-speed railway network (29 stations, 42 trains, and 36,193 passenger trips) demonstrate that the proposed integrated rescheduling method reduces total passenger delays by 13% and trip failures by 67% within a 300 s computational threshold. By systematically coordinating spatiotemporal interdependencies among disruptions, this approach enhances network accessibility and service quality while ensuring operational safety, providing theoretical foundations for intelligent railway rescheduling. Full article

Extreme rainfall events pose a growing threat to slab track subgrades by triggering mud pumping through fines migration and structural voids. This study introduces two innovations to enhance climate resilience in high-speed railway infrastructure: (i) the Rain Intensity Ponding (RIP) method, which links regional rainfall statistics with axle-pass thresholds to predict mud pumping potential; (ii) an optimized drainage retrofit using permeable shoulders and blind ditches. Physical model tests reveal that mud pumping occurs only when structural gaps, ponding, and cyclic loading coincide. The RIP method correctly identified a 71% exceedance in the critical ponding duration (52 min) on a representative high-speed line in Eastern China, explaining recurrent failures. Parametric analyses show that the proposed drainage retrofit—using shoulder fill with ka > 23 mm/s and blind ditches with kg > 23 mm/s—reduces ponding time by up to 90% under 1-year recurrence storms. This study establishes a physics-based, region-specific strategy for mud pumping mitigation, offering guidance for climate-adaptive slab track design and operation. Full article

The extension of high-speed rail (HSR) lines around the world is increasing. The largest network today is in China, followed by Spain, Japan, France, and Italy; currently, new lines are being built in Morocco and Saudi Arabia. The goal of the new lines built is to drastically reduce the time distances between the extreme railway terminals by intervening on the two main components of time: space and speed. The two components have been investigated in various fields of engineering for design conditions (ex ante/a priori). In the literature, there is no analysis of what happened in the realization of the projects (ex post/retrospective). The research problem that arises is to analyze the high-speed lines built in order to verify, given a pair of extreme terminals, how much the length is reduced by passing from a conventional line to a high-speed line, and to verify how this length is getting closer and closer to the distance as the crow flies. The reduction of spatial distance produces direct connections between two territories, making the railway system (HSR) more competitive compared to other transport alternatives (e.g., air travel). To address the problem posed, information and data are collected on European HSR lines, which constitute a sufficiently homogeneous set in terms of railway and structural standards. The planimetric characteristics of specially built lines such as HSR are examined. A test method is proposed, consisting of a model that is useful to compare the length along the HSR line, with direct lengths, and existing conventional lines. The results obtained from the elaborations offer a first answer to the problem posed, demonstrating that in the HSR lines realized the spatial distances approach the distance as the crow flies between the cities located at the extremes, and are always shorter than the lengths of conventional lines. The final indications that can be drawn concern the possibility of using the results obtained as a reference for decision-makers and planners involved in the transport planning process at national and international level. Future research directions should study the values of the indicators in other large HSR networks, such as those built in Asia, and more generally study all the elements of the lines specially built to allow better sustainable planning, reducing the negative elements found and increasing the positive ones. Full article

Lining thinning is a common defect in railway tunnels; however, its impact on shallow four-track high-speed railway (HSR) tunnels—particularly on rock pressure—remains poorly understood. This study investigates the influence of lining thinning on the genuine pressure (also referred to as “deformation pressure”) of such tunnels through field investigation, long-term monitoring, and numerical simulation. Firstly, a lining thinning survey was conducted across ten tunnels, and the statistical distribution of defect parameters was analyzed. Second, over 180 days of field monitoring were carried out in China’s first four-track HSR tunnel (XBS Tunnel) to evaluate the rock pressure state. Third, a three-dimensional numerical model was developed to evaluate the effects of lining thinning and structural degradation on the principal stress, deformation, and genuine pressure of shallow four-track HSR tunnels. The results indicate that thinning defects are widespread, with 38.64% occurring at the vault and over 84% having minimum thicknesses below 0.26 m. The actual rock pressure in the XBS Tunnel was significantly lower than theoretical predictions, and the tunnel primarily experienced genuine pressure rather than loosening pressure during construction, with the secondary lining serving as a safety reserve. Lining thinning leads to stress redistribution and concentration, weakens structural stiffness, and increases the likelihood of damage. It also induces a transition from genuine pressure to loosening pressure, a process that is further accelerated by surrounding rock and lining degradation. The findings provide important insights for the evaluation, design, and long-term maintenance of large-span HSR tunnels. Full article

The construction of high-speed railway (HSR) station areas serves as a crucial catalyst for urban spatial evolution. However, the absence of targeted urban management theories has led to widespread spatial resource waste and post-construction abandonment phenomena in these areas. Existing research predominantly focuses on development strategies for individual construction elements of HSR stations yet lacks comprehensive strategy formulation through coordinated multi-level elements from a sustainable perspective. This study establishes a national database comprising 1018 HSR station area samples across China in 2020, integrating built environment characteristics, HSR network topology, ecological considerations, and socioeconomic indicators. Guided by the land equilibrium utilization theory, we employ the random forest Boruta algorithm to identify critical features, using land supply capacity and development intensity as target variables. Subsequently, K-means++ clustering analysis based on these key variables categorizes the samples into nine distinct clusters. Through normal distribution tests, we establish reference ranges for cluster-specific indicators and propose tailored development strategies across multiple dimensions. This research develops a multimodal feature extraction and evaluation framework specifically designed for the large-scale analysis of HSR station areas. The nine-category strategic recommendations with defined quantitative threshold intervals provide decision-makers with visually intuitive, operationally implementable, and practically significant guidance for spatial planning and resource allocation. Full article

The Belt and Road Initiative’s infrastructure development faces significant challenges in understanding and addressing the divergent perceptions between urban and rural populations, particularly regarding high-speed rail projects. This study investigates the behavioral intentions and sustainability perspectives regarding the China–Laos High-Speed Rail Service among Thai people, with particular focus on urban–rural differences. While the China–Laos railway became operational in December 2021, it is important to note that the high-speed rail extension into Thailand is not yet in operation and remains in the planning and development stage. Using survey data from 2866 respondents (1301 urban and 1565 rural) across 22 Thai provinces, this study employs structural equation modeling to examine relationships between perceived benefits, service quality, cultural factors, emotional aspects, and behavioral intentions. The findings reveal significant urban–rural disparities in infrastructure acceptance patterns. Urban residents demonstrate stronger relationships between perceived benefits and attitudes (β = 0.260) compared to rural residents (β = 0.170), while rural populations show substantially stronger responses to cultural factors (β = 0.365 vs. β = 0.309). Service quality more strongly influences behavioral intentions in rural areas (β = 0.154 vs. β = 0.138), suggesting varying priorities across geographical contexts. The study recommends implementing differentiated development strategies that address these urban–rural differences, including culturally sensitive rural engagement approaches and comprehensive service quality management systems. This research contributes to infrastructure development literature by empirically validating spatial heterogeneity in acceptance factors, extending theoretical frameworks on sustainability perceptions, and providing evidence-based guidance for managing urban–rural disparities in major infrastructure projects. Full article

This study investigated the characteristics and functionalities of China’s High-Speed Railway (HSR) network based on Complex Network Theory (CNT) and Graph Convolutional Networks (GCN). First, complex network analysis was applied to provide insights into the network’s fundamental characteristics, such as small-world properties, efficiency, and robustness. Then, this research developed three novel GCN models to identify key nodes, detect community structures, and predict new links. Findings from the complex network analysis revealed that China’s HSR network exhibits a typical small-world property, with a degree distribution that follows a log-normal pattern rather than a power law. The global efficiency indicator suggested that stations are typically connected through direct routes, while the local efficiency indicator showed that the network performs effectively within local areas. The robustness study indicated that the network can quickly lose connectivity if key nodes fail, though it showed an ability initially to self-regulate and has partially restored its structure after disruption. The GCN model for key node identification revealed that the key nodes in the network were predominantly located in economically significant and densely populated cities, positively contributing to the network’s overall efficiency and robustness. The community structures identified by the integrated GCN model highlight the economic and social connections between official urban clusters and the communities. Results from the link prediction model suggest the necessity of improving the long-distance connectivity across regions. Future work will explore the network’s socio-economic dynamics and refine and generalise the GCN models. 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

There are several accidents in China’s high-speed railways where passengers fall off the platform every year. In response to the risks of falling off high-speed railway platforms associated with passenger overcrowding, this study explores the platform exit width range in determining how to reduce the risk. In order to quantify the risk, we first define the risk probability to measure the likelihood of passengers falling off the platform. Then, we propose an integrated model that combines the passenger flow assignment with a dynamic calculation of passenger flow. This methodology addresses the passenger flow assignment through modeling passenger choices based on path utilities and determines an interpretable exit width range that ensures safe, non-congested evacuation within the designated timeframe. Empirical analysis reveals that the ranges of exit width and achieving different aims of risk probabilities are negatively correlated. The current exit width of 6 m on high-speed railway platforms is insufficient. Our results recommend expanding this width to between 6.43 and 7.01 m to facilitate more efficient passenger exits under normal operating conditions (risk probability of 10%). This adjustment potentially reduces the required investment in surveillance equipment by 77.7% and halves the monetary costs, thereby encouraging railway managers to implement these recommendations. Due to being restricted by a fixed platform width of 10 m, the limitation of optimizing the exit width aims to allow about 2770 passengers at most to leave the platform within the specified travel time. Full article

The CRTS III (China Railway Track System Type III)-girder is susceptible to fatigue damage under high-frequency train loads. However, existing research lacks sufficient focus on the CRTS III-girder and the transverse wheel–rail forces encountered during train operation. To better replicate the stress conditions experienced by high-speed railway track systems, a 1:4 scale CRTS III-girder was fabricated following the principle of mid-span concrete stress equivalence. Subsequently, 9 million transverse and vertical fatigue load cycles were applied to the specimen, leading to the following conclusions: First, no visible cracks appeared on the CRTS III-girder surface during the experiment, indicating strong fatigue resistance under train loads. Second, the box girder primarily exhibited a linear elastic response with minimal stiffness variation. Meanwhile, the upper ballastless track structure experienced a highly complex stress state, with significant variations observed across different layers under cyclic fatigue loading. Third, under fatigue loading, the longitudinal strain of the mid-span track slab and the self-compacting concrete (SCC) layer exhibited an overall decreasing trend, with reduction rates of −66% and −57.9%, respectively. Conversely, the longitudinal strain of the base plate and the top and bottom of the box girder gradually increased, with respective increases of 38.6%, 10.4%, and 12.2%. Finally, the connection between the base plate and the box girder remained robust, showing no relative slippage in the transverse, longitudinal, or vertical directions. The sliding layer exhibited stable performance in the longitudinal direction, with no significant degradation observed under cyclic fatigue loading. However, with increasing load cycles, the transverse relative displacement of the sliding layer gradually increased, reaching a maximum of 0.1 mm. This displacement, in turn, contributed to transverse rail movement, potentially affecting driving safety. Full article

Cement-emulsified asphalt mortar (CA mortar) is an organic–inorganic composite material composed of cement, emulsified asphalt, fine sand, water, and various admixtures. It is mainly used as the cushion layer for high-speed railway ballastless tracks. CA mortar cushion layers in North China often have to withstand the coupling effects of humidity and freeze–thaw, which has a very important impact on the fatigue performance of CA mortar. Based on the big data statistical results, the temperature conditions and cycle times of the CA mortar layer Freeze–Thaw cycle in North China were determined. Also, a fatigue performance test under humidity–freeze–thaw coupling conditions was designed and carried out. The fitting curve equations of fatigue stress and fatigue life under different humidity conditions and freeze–thaw coupling were established. The relationship between fatigue performance parameters K and n and humidity conditions was analyzed. This study shows that with the increase in humidity, the fatigue life of CA mortar under different humidity conditions shows an overall downward trend. The fatigue performance and fatigue life stress level sensitivity of CA mortar decrease with increasing humidity. The proportion of water damage and freeze–thaw damage to total damage increases with increasing humidity, which means that the humidity and freeze–thaw have a more significant impact on the fatigue properties of CA mortar. When the humidity is low, the fatigue cracks of CA mortar are mostly generated across the cement paste, and the macroscopic damage presents as longitudinal cracking. When the humidity is high, the fatigue cracks of CA mortar are mostly generated at the interface between aggregate and paste, and the macroscopic damage presents as oblique cracking. Based on the analysis of the damage mechanism, it is suggested that the humidity of CA mortar should be controlled below 25% in the actual project to ensure its durability. Full article

High-speed railway (HSR) has become a key infrastructure that shapes land use, specifically industrial distribution, and therefore affects urban industrial structure and regional economic patterns. This paper develops a new approach to examine the intercity industrial distribution effects (IDE) of HSR using nighttime light (NTL) data from 290 cities in China over a long period of time. Our study shows that the tertiary industries exhibit higher luminous intensity than the secondary industries, and the operation of HSR fosters the concentration of tertiary industries in megacities and supercities, especially those in the eastern economic regions, while leading to the dispersion of secondary industries from those cities. As a result, the proportion of tertiary industry in most medium and small cities decreased, and that of the secondary industry increased. Furthermore, among tertiary industries, producer services, especially transportation, warehousing, postal services, financial services, and leasing and business services, are most affected by HSR. These results highlight the intercity variation in the industrial impacts of HSR and provide valuable insights for industrial planning and policy-making in HSR cities. The proposed approach in this study can effectively identify the IDEs of HSR. Our findings suggest that cities cannot blindly rely on the operation of HSR to pursue economic development, and policymakers need to consider both the industrial situation of the HSR city itself and that of the cities connected through HSR to formulate distinct land use policies to address the impact of HSR on its industries. Full article