High-speed Railway In China Research Articles

Fiscal policy and the development of green transportation infrastructure: the case of China's high-speed railways

High-speed rail (HSR) has been highly valued as an accelerator of green economic growth. However, the difficulty in financing caused by the high investment demand and long construction cycle of high-speed rail is an ongoing dilemma facing the high-speed rail industry. Using data from Chinese cities from 2003 to 2018, this paper explores whether fiscal policy is conducive to solving financing problems for high-speed railway construction. At the same time, this paper investigates the economic and environmental benefits of high-speed rail construction investment for urban development. We find that fiscal policy helps reduce the financing cost of high-speed railway construction projects and attracts social capital, spurring investment in high-speed rail construction. When economic policy uncertainty rises, companies will choose more secure, "safe" investments to avoid potential risks, such as government-led high-speed rail construction projects, which has led to their further expansion. Regarding its economic effect, high-speed rail construction investment directly promotes urban productivity, investment scale, and industrial structure upgrades. Over the long term, investment in HSR construction helps curb urban pollutant emissions, thus contributing to urban eco-efficiency.

External hydraulic pressure and invert uplift study in a non-circular shallow tunnel

Water hazards experienced in mountain tunnels have always been associated with inadequacy of waterproof structures and grouting technology applied in the construction stage. But the knowledge of seepage caused by groundwater inflow during the operation stage remains limited despite its importance to tunnel traffic operation and general safety. In this paper, the concept of equivalent permeability lining is introduced and the external hydraulic pressure (EHP) distribution of shallow non-circular tunnel is analytically deduced. A set of numerical and model tests are presented based on the semi-enclosed drained tunnel of a high-speed railway in China. The result shows that the existing circular solution underestimates the invert external hydraulic pressure (EHP) of non-circular shallow tunnel. A staged failure mode of high-EHP semi-enclosed tunnel can be observed in model tests. The vulnerabilities of warning criterion and monitoring put the high EHP tunnel under risk. Based on these, a modified analytical solution, a new warning criterion and a new maintainable monitoring system are built for high EHP tunnel.

Mixed logit model based on nonlinear random utility functions: a transfer passenger demand prediction method on overnight D-trains

In recent years, with the development of high-speed railway in China, the operating mileage and passenger transport capacity have increased rapidly in transportation industry. Due to the high density of trains in the daytime, we usually set up skylights at night (0:00–6:00 am) on high-speed railway for comprehensive maintenance. However, this arrangement contradicts with the operation demand of D-series overnight high-speed trains (overnight D-trains for short). In order to adjust the operation plan of overnight D-trains with skylights coordinately, it is necessary to predict the passenger demand of newly added overnight D-trains. Therefore, in this paper, a mixed logit model based on nonlinear random utility functions for different transport modes is proposed, in order to predict transfer passenger demand. According to Maximum Simulated Likelihood Method, the likelihood function of this mixed logit model is proposed to maximize the overall utility value of different passenger groups while Metropolis–Hastings algorithm is adopted to iteratively solve the probabilities of discrete random variables in utility functions. After that, the unknown distributions of parameters are estimated and the optimal solution of this model is provided by traditional algorithms, basic heuristic algorithms and improved heuristic algorithms including improved fireworks-simulated annealing algorithm proposed in this paper, respectively. Finally, a real-world instance with related data of Beijing–Shanghai corridor is implemented to demonstrate the performance and effectiveness of the proposed approaches.

The Microstructure and Mechanical Properties of 5083, 6005A and 7N01 Aluminum Alloy Gas Metal Arc-Welded Joints for High-Speed Train: A Comparative Study

This study aimed to conduct a comparative study on the microstructure and mechanical performance of 5083, 6005A and 7N01 Al joints used in China Railway High-speed (CRH) trains. We connected 10 mm-thick plates by three-layer and three-pass gas metal arc welding (GMAW). The results indicated that 6005A and 7N01 Al joints were more sensitive to grain boundary liquation in the partially melted zone (PMZ) than 5083 Al joins. Besides, recrystallization was obtained in heat-affected zones (HAZ). The 5083 Al joints experienced the most severe recrystallization and the grain size changed from 6.32 (BM) to 32.44 (HAZ) μm duo to intracrystalline strain induced by cold-rolled processes. The 7N01 Al alloys experienced the lowest extent of recrystallization and the grain size increased from 5.32 (BM) to 22.31 (HAZ) μm. Furthermore, significant precipitate evolution in the HAZ was observed. Original thin β” precipitates dissolved in HAZ of 6005A Al joints and transformed to the softer β phase. However, less precipitation transition was examined in 5083 and 7N01 Al joints. The precipitates’ evolution produced a softening region in HAZ of 6005A joints where the hardness was only 55 HV. The microhardness profile of the other two Al joints was less affected. The tensile strength of 5083, 6005A, and 7N01 Al alloy joints reached 323, 206 and 361 MPa, respectively. The 5083 Al and 6005A Al joints failed at HAZ near the fusion line while 7N01 Al joints failed at the fusion zone owing to the high strength of the base metal. The liquation, coarse grains by recrystallization, and precipitate evolution all decreased local strength, resulting in the fracture at HAZ.

Analytical calculation method for passive tensile damage of asphalt concrete waterproof sealing structure of ballastless track subgrade

The theoretical development of the temperature effect of the full-section asphalt concrete waterproof sealing structure (ACWSS) of the ballastless track subgrade lags the engineering practice. In order to reveal the passive tensile damage behavior of ACWSS from the perspective of theoretical analysis, in this paper, the base plate of the ballastless track and the ACWSS is simplified into an elastic–viscoelastic double layer composite beam model. The analytical calculation method for passive tensile damage of ACWSS under temperature load is derived theoretically. The change of surface stress and strain of ACWSS with time is calculated and analyzed. The theoretical analysis and calculation results show that the variation of the surface strain, the maximum strain, and the time corresponding to the strain peak of ACWSS are consistent with the measured results. The model of the double-layer composite beam has high reliability, and the analytical calculation method of passive tensile damage is reasonable and practical. The temperature stress of ACWSS at the expansion joint of the base plate is synchronized with the temperature change, indicating that the asphalt concrete at this location is mainly subjected to axial tension (or compression). It is suggested that the structural design should be judged by comparing the number of periodic temperature loads and the allowable fatigue number of asphalt concrete, which further improves the design method and technical system of the ACWSS in China's high-speed railway. It has important theoretical and practical significance.

Interaction and Impact of the Tourism Industry on High-Speed Railway in China

Interaction and Impact of the Tourism Industry on High-Speed Railway in China

Study on the Dynamic Performance of High-Speed Railway Catenary System With Small Encumbrance

The catenary system is the only source of power for high-speed railways, which carries the electric current to be collected by a pantograph mounted on the train roof via sliding contact. The height difference between the contact wire and the messenger wire at the support is called the encumbrance of the catenary, which is normally restricted to satisfy the demand of wind protection in an open environment and reduction of clearance in the tunnel. The reduction of the catenary’s encumbrance consequently decreases the droppers’ length and affects the interaction performance of the pantograph-catenary. This paper is the first attempt to make sense of the pantograph-catenary interaction performance with small encumbrance. Firstly, the compression characteristics tests of short droppers of different lengths are performed. Based on the test results, a nonlinear dropper model that considers the tension-compression property is proposed. Then a pantograph-catenary model integrated with the modified dropper model is built. Taking a China high-speed railway as an analysis object, the effect of encumbrance on the dynamic performance is investigated. The results demonstrate that the traditional dropper model cannot fully describe the dynamic behavior of the catenary with small encumbrance. The deterioration of the dynamic performance of the small encumbrance catenary is mainly caused by the compressing force generated from the compressed droppers. When the length of the shortest dropper is less than 400 mm, the interaction performance of pantograph-catenary deteriorates significantly. In contrast, when the length of the shortest dropper exceeds 900 mm, the encumbrance does not have a distinct implication on the dynamic performance. It is suggested that the shortest dropper length should exceed 400 mm to ensure acceptable dynamic performance.

Characteristics of the evolution of the industrial structure of the high-speed railway station area under the influence of location factors

At present, the large-scale construction of the high-speed railway is in the stage of accelerated urbanization, and the industrial space of the high-speed railway station area has also emerged with many problems in its development. This paper takes the current characteristics of China's high-speed railway construction and the problems faced by the current industrial space in station areas as a starting point. Six urban central and fringe station areas are selected as research cases to explore the characteristics of location factors on the industrial structure and spatial aggregation of high-speed railway station areas. The study finds that the early service system of urban central stations is more complete than that of urban fringe stations, and the industrial structure of fringe stations changes more obviously and is more influenced by the economic impact of high-speed rail passenger flow; the increase in the number of enterprises in urban central stations and fringe station areas is spatially directional, while the overall clustering pattern shows an opposite trend.

How Does Successful Catch-Up Occur In Complex Product and Systems from An Innovation Ecosystem Perspective? The Case of China's High-Speed Railway

How Does Successful Catch-Up Occur In Complex Product and Systems from An Innovation Ecosystem Perspective? The Case of China's High-Speed Railway

High-speed railways and local economic performance: evidence from China’s prefecture-level cities

PurposeThe purpose of this paper is to identify the causal effect of high-speed railways (HSRs) and investigate the affecting channels; the second purpose is to examine how HSRs change the distribution of economic activity across cities and sectors.Design/methodology/approachA difference-in-difference strategy is implemented to estimate the impact of recently built HSRs on local economic performance in China, exploiting the geography and time variations in HSR operations.FindingsUsing panel data from China’s City Statistical Yearbook 2001–2019, the authors find that HSRs lead to a significant increase in cities’ gross domestic product (GDP) and GDP per capita, but the authors do not find any significant change in GDP growth. This conclusion still holds true after the authors address the endogeneity problems. A mechanism analysis shows that HSRs improve local economic performance mainly by increasing fixed asset investment. The authors also find that the HSR investment is a policy that favors metropolitan areas due to the larger increase in the GDP for larger cities and with HSRs, the industrial and service sectors will further agglomerate in larger cities.Originality/valueThe authors contribute to the literature in several ways. First, this paper improves the estimation strategy in identifying the HSR impact on the local economic performance. Second, this paper investigates the affecting channels of HSRs. This paper proves that HSRs in China promote the cities’ economic performance mainly by increasing the fixed asset investment. Third, this study provides evidence for the new economic geography models pioneered by Krugman (1991).

Design theories and maintenance technologies of slab tracks for high-speed railways in China: a review

Abstract The durability and reliability of slab track structures are essential for the long-term safety and stable operation of high-speed railways. In order to provide a solid theoretical basis and technical reference for the advancement of high-speed railway quality, this paper comprehensively discusses design theories of slab track structures, service performance evolution and maintenance technologies, and reviews the innovation happening in the industry. On top of that, the damage evolution, fatigue features and durability of slab tracks, which are highly relevant to serviceability, are summarized, and the future research trend of slab track service behaviours is pointed out. In addition, this paper summarizes the rules of establishing standards for damage maintenance, typical solutions for repairing damage and methods of evaluating the maintenance outcomes that combine field tests and numerical simulations. It also envisions a future direction where advanced testing technologies would assist the evaluation of maintenance effects.

Optimal Differential Pricing for Intercity High-Speed Railway Services with Time-Dependent Demand and Passenger Choice Behaviors under Capacity Constraints

Differential pricing of trains with different departure times caters to the taste heterogeneity of the time-dependent (departure time) demand and then improves the ticket revenue of railway enterprises. This paper studies optimal differential pricing for intercity high-speed railway services. The distribution features of the passenger demand regarding departure times are analyzed, and the time-dependent demand is formulated; a passenger assignment method considering departure periods and capacity constraints is constructed to evaluate the prices by simulating the ticket-booking process. Based on these, an optimization model is constructed with the aim of maximizing the ticket revenue and the decision variables for pricing train legs. A modified direct search simulated annealing algorithm is designed to solve the optimization model, and three random generation methods of new solutions are developed to search the solution space efficiently. Experimental analysis containing dozens of trains is performed on Wuhan-Shenzhen high-speed railway in China, and price solutions with different elastic demand coefficients ( ϕ ) are compared. The following results are found: (i) the optimization algorithm converges stably and efficiently and (ii) differentiation is shown in the price solutions, and the optimized ticket revenue is influenced greatly by ϕ , increasing by 7%–21%.

Effect of High-Speed Railways on City Industrial Sewage Discharge

Industrial wastewaters threatening the sustainability of society have increasingly become a key social issue across the globe. Consequently, countermeasures have been suggested across a broad range of research fields and policy cycles in both industrialized and industrializing countries. Thus, identifying factors that drive reductions in industrial wastewater discharge is a key task in the water research and policymaking fields. In contrast to previous studies that have focused on reducing industrial wastewater discharge through techniques, policy, management, and other tools, the aim of this study was to investigate the effect of transport infrastructure development, particularly high-speed railways (HSR), on industrial sewage discharge. Given the rapid development of high-speed railways in China and the country’s severe water pollution, China was our research context, and our sample was 298 prefecture-level Chinese cities during the period 1999–2018. The empirical results show that cities with high-speed railways have greater reductions in industrial wastewaters, and that these effects are weakened in cities with a more developed economy and information environment. The results are consistent when using different methods to test their robustness, such as time-varying difference-in-difference (DID), instrumental variables, and placebo tests. These findings offer useful guidance for practitioners and policymakers in the management of water resources and the development of transport infrastructure in cities. These results contribute to the literature in the field of water management and to the assessment of the broader effect of high-speed railways.

Natural disaster warning system for safe operation of a high-speed railway

Abstract In this paper, the least square support vector machine (LSSVM) is used to study the safety of a high-speed railway. According to the principle of LSSVM regression prediction, the parameters of the LSSVM are optimized to model the natural disaster early warning of safe operation of a high-speed railway, and the management measures and methods of high-speed railway safety operation under natural disasters are given. The relevant statistical data of China's high-speed railway are used for training and verification. The experimental results show that the LSSVM can well reflect the nonlinear relationship between the accident rate and the influencing factors, with high simulation accuracy and strong generalization ability, and can effectively predict the natural disasters in the safe operation of a high-speed railway. Moreover, the early warning system can improve the ability of safety operation evaluation and early warning of high-speed railway under natural disasters, realize the development goals of high-speed railway (safety, speed, economic, low-carbon and environmental protection) and provide a theoretical basis and technical support for improving the safety of a high-speed railway.

Effects of Wheel-Rail Impact on the Fatigue Performance of Fastening Clips in Rail Joint Area of High-Speed Railway

In order to study the effects of wheel-rail impacts on the fatigue damage of the fastening clips at the rail joints of a high-speed railway, field tests were carried out on the wheel-rail impacts at the rail joints of a high-speed railway in China. On the basis of the track irregularities at the rail joints obtained from field measurements, a nonlinear vehicle-track coupling dynamics three-dimensional (3D) model with consideration of Timoshenko beam elements and a refined finite element model of WJ-8 fastening system were constructed. And combined with the theory of cumulative damage and the method of fatigue analysis, the effects of wheel-rail impact at the rail joints on the fatigue life of fastening clips were analyzed. The results showed that the impacts of the wheel-rail in the joint area caused high-frequency fluctuations in the stress-time curves of the clips, which significantly increased the amplitude of stress cycle and increased a lot of stress cycles, of which the amplitudes were reached at a large level; the clips in the area where a rail joint was located suffered the most serious fatigue damage and had the shortest fatigue life; in the actual operation line, besides the clips in the rail joint area, it is also necessary to be concerned about the fatigue performance of fastening clips near the rail joint area.

Testing research on frequency-dependent characteristics of dynamic stiffness and damping for high-speed railway fastener

In this paper, the Vossloh W300 fastener currently used in China's high-speed railway is taken as the research object. Combined with the requirements of ISO 10846 series standards and the knowledge of the author, to the best of the authors knowledge, the first high-frequency dynamic stiffness test system for elastic elements of rail fastener has been successfully developed and built. By taking the influence of preloading into consideration, the vertical and lateral dynamic frequency-dependent stiffness and loss factor of high-speed railway W300 fastener at 5~1250 Hz were obtained through the 1:1 test model coupling test method for the first time. Referring to the prediction method of high-speed railway wheel-rail vibration and noise, and factoring in the high-speed rotating, the infinite length of plate track structure and high-speed movement of sound source to wheels, the Kelvin - Voigt simulation sub-model of fastening system was added to predict and analyze the difference between the total sound pressure levels of the wheel and rail that is relative to the standard point under the constant stiffness and frequency-dependent stiffness of fastener. The results indicate that the frequency-dependent characteristics of fastener stiffness have significant impact on the spectrum of wheel-rail interaction forces, total sound pressure levels of rail and wheel-rail. The total sound pressure level of the wheel-rail relative to standard point, which factors in the frequency-dependent stiffness of fastener was approximately reduced 2.6 dB, that is, the frequency-dependent stiffness of fastener can rectify the overestimation of wheel-rail sound pressure level by stiffness coefficient.

High-speed railways and collaborative innovation

This paper investigates the impact of infrastructure on innovation collaboration between enterprises in different locations using the introduction of high-speed railways in China. Applying an instrumental variable approach to control for the endogeneity of high-speed railways, and using a large enterprise census that includes both manufacturing and service sectors in China, we find that high-speed railways can improve innovation collaboration substantially at the city level. More importantly, we match city pairs based on high-speed railway routes and calculate the amount of time saved by a high-speed railway for each city pair. The empirical results suggest that the innovation collaboration also increases significantly at the city-pair level. Innovation quality, measured by patent citations between cities, also increases. Further evidence on spatial heterogeneity, industry heterogeneity and ownership heterogeneity suggests that the impact of high-speed railways is more significant for collaboration in less developed regions, in the service sector and in domestic enterprises.

Predicting the effectiveness of supplement time on delay recoveries: a support vector regression approach

ABSTRACT Investigating the effectiveness of supplement time is a critical method for dispatchers to understand the delay recovery capacity of railway sections and stations, thus improving real-time dispatching efficiency. Based on train operation data of the high-speed railway in China, a support vector regression (SVR) algorithm was employed to investigate the effectiveness of supplement times in railway sections and stations. First, the independent factors were determined, and the hyper-parameters of the SVR model were tuned with the operation data. Then, the performance of the predictive model was tested on the testing dataset. The results show that the predicted delay recovery cases of the model coincide highly with the actual cases. Additionally, the predictive performance of the model under allowable errors illustrates that the accuracy of the model can reach 95.96%, with a 1-minute allowable error. Finally, comparison analyses show that the proposed model outperforms other widely-used delay recovery models.

Subsurface settlements of shield tunneling predicted by 2D and 3D constitutive models considering non-coaxiality and soil anisotropy: a case study

Appropriate constitutive models and reliable excavation and support sequences are believed to be the major concern in using finite element (FE) analysis to simulate shield tunnel excavation. This paper presents systematic two-dimensional (2D) and three-dimensional (3D) FE analyses employing a number of constitutive models accounting for initial soil anisotropy and non-coaxial plasticity, as evidenced within site investigations from the Tsinghuayuan Tunnel of the Jing-Zhang high-speed railway in China. The aim is to assess the effects of both the initial soil anisotropy and non-coaxiality on longitudinal and transverse tunneling-induced surface settlements. It is shown that the excavation procedures combined with the degree of cross-anisotropy are key towards the accurate prediction of maximum vertical displacements from tunneling, matching field data. Knowledge of the initial soil strength anisotropy can further improve the shape prediction of the transverse tunneling-induced surface settlement troughs. When considering n = 0.6 and β = 0° in simulations, the transverse surface settlement trough obtained is almost coincident with monitored field data. Initial stiffness anisotropy used in the prediction of shield tunnel-induced surface settlements in sandy pebble soils does improve realism of results significantly. The maximum longitudinal settlement predicted by considering cross-anisotropy is larger than that predicted by its isotropic counterpart.

Track Irregularity Monitoring on High-Speed Railway Viaducts: A Novel Algorithm with Unknown Input Condensation

The inverse dynamic analysis of vehicle-bridge (VB) systems provides a superior scheme for track irregularity identification using the onboard measurement data of vehicle dynamic responses. However, available algorithms face a great challenge when applied to high-speed railway bridges because of the increase in the number of unknown inputs, resulting in a degradation of identification accuracy. Here, we propose a condensation procedure to reduce the unknown inputs of the VB system, and then propose a novel algorithm for track irregularity identification using the augmented Kalman filter. A numerical simulation of a real continuous three-span simply supported railway bridge was conducted to validate the estimation accuracy of the proposed algorithm. Numerical results illustrate that the proposed algorithm can accurately estimate the track irregularities by using the vertical acceleration responses of the vehicle body only, thanks to the unknown input condensation. A comparative study demonstrates that the proposed algorithm outperforms the conventional track irregularity identification methods in terms of estimation accuracy. To evaluate the actual performance of the proposed algorithm, a set of onboard measurement data recorded by a typical high-speed train when running on the Hangzhou–Changsha high-speed railway in China was employed to identify the track irregularities of the railway line, and the results suggest that the proposed algorithm is highly efficient and low in cost. This study may help develop highly efficient real-time track irregularity monitoring in the years ahead.