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The purpose of this paper is to summarize the status and characteristics of rail technology of high-speed railway in China, and point out the development direction of rail technology of high-speed railway.

This study reviews the evolution of high-speed rail standards in China, comparing their chemical composition, mechanical attributes and geometric specifications with EN standards. It delves into the status of rail production technology, shifts in key performance indicators and the quality characteristics of rails. The analysis further examines the interplay between wheels and rails, the implementation of grinding technology and the techniques for inspecting rail service conditions. It encapsulates the salient features of rail operation and maintenance within the high-speed railway ecosystem. The paper concludes with an insightful prognosis of high-speed railway technology development in China.

The rail standards of high-speed railway in China are scientific and advanced, highly operational and in line with international standards. The quality and performance of rail in China have reached the world’s advanced level. The 60N profile guarantees the operation quality of wheel–rail interaction effectively. The rail grinding technology system scientifically guarantees the long-term good service performance of the rail. The rail service state detection technology is scientific and efficient. The rail technology will take “more intelligent” and “higher speed” as the development direction to meet the future needs of high-speed railway in China.

The development direction of rail technology for high-speed railway in China is defined, which will promote the continuous innovation and breakthrough of rail technology.

High-speed maglev technology can address the issues of adhesion, friction, vibration and high-speed current collection in traditional wheel-rail systems, making it an important direction for the future development of high-speed rail technology.

This paper elaborates on the demand and significance of developing high-speed maglev technology worldwide and examines the current status and technological maturity of several major high-speed maglev systems globally.

This paper summarizes the challenges in the development of high-speed maglev railways in China. Based on this analysis, it puts forward considerations for future research on high-speed maglev railways.

This paper describes the development status and technical maturity of several major high-speed maglev systems in the world for the first time, summarizes the existing problems in the development of China's high-speed maglev railway and on this basis, puts forward the thinking of the next research of China's high-speed maglev railway.

This method will become a new development trend in subgrade structure design for high speed railways.

This paper summarizes the structural types and design methods of subgrade bed for high speed railways in China, Japan, France, Germany, the United States and other countries based on the study and analysis of existing literature and combined with the research results and practices of high speed railway subgrade engineering at home and abroad.

It is found that in foreign countries, the layered reinforced structure is generally adopted for the subgrade bed of high speed railways, and the unified double-layer or multi-layer structure is adopted for the surface layer of subgrade bed, while the simple structure is adopted in China; in foreign countries, different inspection parameters are adopted to evaluate the compaction state of fillers according to their respective understanding and practice, while in China, compaction coefficient, subsoil coefficient and dynamic deformation modulus are adopted for such evaluation; in foreign countries, the subgrade top deformation control method, the subgrade bottom deformation control method, the subsurface fill strength control method are mainly adopted in subgrade bed structure design of high speed railways, while in China, dynamic deformation control of subgrade surface and dynamic strain control of subgrade bed bottom layer is adopted in the design. However, the cumulative deformation of subgrade caused by train cyclic vibration load is not considered in the existing design methods.

This paper introduces a new subgrade structure design method based on whole-process dynamics analysis that meets subgrade functional requirements and is established on the basis of the existing research at home and abroad on prediction methods for cumulative deformation of subgrade soil.

This paper aims to analyze the bearing characteristics of the high speed train window glass under aerodynamic load effects.

In order to obtain the dynamic strain response of passenger compartment window glass during high-speed train crossing the tunnel, taking the passenger compartment window glass of the CRH3 high speed train on Wuhan–Guangzhou High Speed Railway as the research object, this study tests the strain dynamic response and maximum principal stress of the high speed train passing through the tunnel entrance and exit, the tunnel and tunnel groups as well as trains meeting in the tunnel at an average speed of 300 km·h-1.

The results show that while crossing the tunnel, the passenger compartment window glass of high speed train is subjected to the alternating action of positive and negative air pressures, which shows the typical mechanic characteristics of the alternating fatigue stress of positive-negative transient strain. The maximum principal stress of passenger compartment window glass for high speed train caused by tunnel aerodynamic effects does not exceed 5 MPa, and the maximum value occurs at the corresponding time of crossing the tunnel groups. The high speed train window glass bears medium and low strain rates under the action of tunnel aerodynamic effects, while the maximum strain rate occurs at the meeting moment when the window glass meets the train head approaching from the opposite side in the tunnel. The shear modulus of laminated glass PVB film that makes up high speed train window glass is sensitive to the temperature and action time. The dynamically equivalent thickness and stiffness of the laminated glass and the dynamic bearing capacity of the window glass decrease with the increase of the action time under tunnel aerodynamic pressure. Thus, the influence of the loading action time and fatigue under tunnel aerodynamic effects on the glass strength should be considered in the design for the bearing performance of high speed train window glass.

The research results provide data support for the analysis of mechanical characteristics, damage mechanism, strength design and structural optimization of high speed train glass.

This paper aims to document and to illustrate highly usable research: a practical framework for realizing the sustainable operations of the high investment, technology-intensive high-speed railways in China. Also, for the first time, we draw a broad, metaphorical relationship between railways within a country to Chinese meridian lines within a human body. These are similar in enabling flows across the country and human body.

Employing Chinese case studies, we attempt to apply methodological procedures involving operational, financial and developmental in realizing the sustainability of high-speed railways. Critical criteria are emphasized for efficiency, financial viability and long-term funding sustained development of high-speed railways in the Chinese context. Policymakers may utilize the illustrative framework in working toward specific recommendations that may be implementable.

Three critical aspects to sustainability are operational, financial solvency and developmental. Our empirical investigations result in the working out of the procedural aspects as well. Based on this three-way classification, we design an evaluative framework for realizing sustainability of high-speed railways. Our insights are based on the social reality of China. Thus, we argue that cash handouts by government are necessary solutions, given the intensive capital investments required of high-speed railways for strongly positive externalities generated. On developmental aspects of sustainability, there should be rational, in-depth studies conducted so as to lead to rational choices of sites. Strong passenger flows coupled with affordability of fares are the twin guarantees of continuing, profitable performances.

This work on sustainability is globally, most highly significant for two reasons. First, railway is one fundamental mean of transportation within China. Thus, the sustainability of railway matters to a majority of the 1.3 billion people. Second, transport volume of China’s railway is the world’s largest. By developing such a comprehensive methodology, we hope to enhance how top management of Chinese Railways may keep the high-speed railways sustainable into the future.

This paper is socially highly significant, especially in the context of what has happened in recent years in China’s railway industry, and may contribute by providing both the regulators and management with an objective methodology in future projects assessment within high-speed railway.

This paper develops an overall framework for enabling management to realize sustainability of high-speed railway within China. The ideas, concepts and methodologies are likely beneficial to top management, regulators and policymakers within the railway transportation, a state monopoly.

The nose length is the key design parameter affecting the aerodynamic performance of high-speed maglev train, and the horizontal profile has a significant impact on the aerodynamic lift of the leading and trailing cars Hence, the study analyzes aerodynamic parameters with multi-objective optimization design.

The nose of normal temperature and normal conduction high-speed maglev train is divided into streamlined part and equipment cabin according to its geometric characteristics. Then the modified vehicle modeling function (VMF) parameterization method and surface discretization method are adopted for the parametric design of the nose. For the 12 key design parameters extracted, combined with computational fluid dynamics (CFD), support vector machine (SVR) model and multi-objective particle swarm optimization (MPSO) algorithm, the multi-objective aerodynamic optimization design of high-speed maglev train nose and the sensitivity analysis of design parameters are carried out with aerodynamic drag coefficient of the whole vehicle and the aerodynamic lift coefficient of the trailing car as the optimization objectives and the aerodynamic lift coefficient of the leading car as the constraint. The engineering improvement and wind tunnel test verification of the optimized shape are done.

Results show that the parametric design method can use less design parameters to describe the nose shape of high-speed maglev train. The prediction accuracy of the SVR model with the reduced amount of calculation and improved optimization efficiency meets the design requirements.

Compared with the original shape, the aerodynamic drag coefficient of the whole vehicle is reduced by 19.2%, and the aerodynamic lift coefficients of the leading and trailing cars are reduced by 24.8 and 51.3%, respectively, after adopting the optimized shape modified according to engineering design requirements.

The high-speed rail network can lead to the transformation of the tourism industry, as well as the regional economy. In the present study, a reasonable method was developed to assess the contributions of high-speed rail network to the development of tourism and economy in a Chinese region known as the “1 + 8” city tourism circle.

The method proposed here combines not only tourism revenue but also regional economy in a MGM (1, n) gray model, and it studies the tourist and economic output of this tourism circle before and after the high-speed rail network’s construction using an advanced “with and without comparison” method.

By using this method, the accuracy of the prediction of the contribution rate of high-speed rail network is improved. We found that in the “1 + 8” city tourism circle, the high-speed rail network positively contributes to increase of the tourism arrival and tourism revenue. Furthermore, regional economy significantly grows under the impact of the high-speed rail network.

The “1 + 8” city tourism circle is studied as a closed system in this paper, and the authors focus on the economic associations between the cities in the circle by ignoring the impact from outside this circle. This treatment means, simplifies and enables the feasibility of this study, but it virtually leads to the deviation of outcomes between this study and the practical.

For theoretical values, by studying a normal Chinese inland region, this study reconfirmed the positive impact of high-speed railway empirically. In the meantime, this study developed an improved method by introducing gray theory models to “with and without comparison” method to calculate the contribution of high-speed railway to the regional tourism and economy development. Such method simultaneously incorporates the indexes of regional tourism income and regional GDP simultaneously. It is direct and convenient as it can achieve accuracy requirements using only a small amount of data, and it reconciles more with reality by considering the interaction of the outcomes of tourism and economy.

For practical values, using the proposed method, a direct and convenient calculation of the contributions of high-speed railway to many other regions can be achieved if the data of the outcomes of tourism and economy can be obtained. In such a way, the regions that really need high-speed railway to stimulate their development can be distinguished from regions whose high-speed railway is under blind construction. Thus, the government may take actions to reassess some uneconomic high-speed railway projects without discouraging the construction of high-speed railway in other regions. The authors believe that this is important not only for China but also for many other countries with high-speed railway projects.

This study develops a reasonable method of assessing the contribution of high-speed rail to regional tourism and economic development. Using this method, this study confirmed that high-speed rail indeed positively impacts the regional development.

抽象

高速铁路（HSR）网络可以带动旅游业乃至区域经济的转型。本研究构建了一个合理的方法来评估高铁网络对中国 “1+8” 城市旅游圈的旅游产业和区域经济发展的贡献。

本文提出的方法将旅游收入和区域经济的指标结合在一个MGM（1，n）灰色模型中，并采用先进的 “有无比较法” 来研究高铁网建设前后该旅游圈的旅游和经济产出。

利用该方法，可更精准地预测高速铁路网的贡献率。研究发现，在“1+8” 城市旅游圈中，高铁网络对游客到访量和旅游收入的增加起到了积极的促进作用。此外，在高铁网络的影响下，区域经济得到了显著增长。

本文将 “1+8” 城市旅游圈作为一个封闭的系统进行研究，忽略了外部因素的影响，而重点研究旅游圈内城市之间的经济联系。这种处理方法简化了本研究的过程，增加了研究的可行性，但实际上导致了本研究结果与现实存在偏差。

就理论上而言，本文通过对一个典型的中国内陆地区展开研究，从经验上重新确认了高速铁路的积极影响。同时，将灰色理论模型引入到“有无比较法” 中，提出了一种改进方法，用以计算高速铁路对区域旅游业和经济发展的贡献。该方法同时结合了区域旅游收入和GDP指标，十分直接方便，只需要少量数据就可以达到准确的要求；并且由于它考虑到了旅游业和经济的相互作用，更符合实际。

就实用价值而言，只需获得旅游业和经济成果的数据，即可利用该方法直接方便地计算高铁对众多其他地区的贡献。这样一来，就可以将真正需要高铁来刺激发展的地区与盲目建设高铁的地区区分开来。由此，政府可以对一些不经济的高速铁路项目进行重新评估，而不妨碍其他地区的高铁建设。笔者认为，这对中国乃至其他许多国家的高铁项目建设来说是很重要的。

本研究提出了一种合理的方法来评价高铁对区域旅游业和经济发展的贡献。利用这一方法，本研究证实了高铁确实对区域发展产生了积极的影响。

Resumen

La red de ferrocarril de alta velocidad (HSR) puede liderar la transformación de la industria turística, así como la economía regional. En el presente estudio, se ha desarrollado un método para evaluar las contribuciones de la red ferroviaria de alta velocidad, en el desarrollo económico en una región China conocida como el círculo de turismo urbano “1+8”.

El método que se propone combina, no solamente los ingresos por turismo, sino también la economía regional en un modelo MGM (1,n) gris, y estudia la producción turística y económica de este círculo turístico, antes y después de las construcción de la red ferroviaria de alta velocidad utilizando un método “con y sin comparación”.

Usando este método, se mejora la predicción de la tasa de contribución de la red de alta velocidad. Nosotros descubrimos que en el círculo “1+8”, la red ferroviaria de alta velocidad contribuye positivamente al aumento en la llegadas de turistas y los ingresos por turismo. Además, la economía regional, crece significativamente bajo el impacto de esta red.

En este artículo, el círculo de turismo urbano “1+8”, se estudia como un sistema cerrado, se enfoca en la asociación económica entre las ciudades, pero ignorando el impacto desde fuera. Este tratamiento significa simplificar y habilitar la viabilidad de este estudio, pero prácticamente conduce a la desviación de los resultados entre este estudio y la practica.

El valor teórico, estudiando una región normal del interior de China, reconfirma el impacto positivo del ferrocarril de alta velocidad. Mientras tanto, este estudio desarrolla un método mejorado, introduciendo los modelos de “teoría gris” en los métodos “con y sin comparación”, para el calculo de la contribución del ferrocarril de alta velocidad en el desarrollo de la economía regional y turística. Además y simultáneamente, el método incorpora los índices de ingresos del turismo regional y el PIB. Esto es directo y conveniente, ya que puede cumplir con los requisitos de precisión, usando solamente una pequeña cantidad de datos, y concilia más con la realidad considerando la interacción del resultado del turismo y economía.

Para los valores prácticos, usando el modelo propuesto, se puede lograr un cálculo directo y conveniente de las contribuciones del ferrocarril de alta velocidad a muchas otras regiones, y se pueden obtener datos del impacto del turismo y la economía. De esta manera, las regiones que realmente necesiten el ferrocarril de alta velocidad para estimular su desarrollo, se podrán diferenciar de aquellas otras que lo planteen a ciegas. Por lo tanto, los gobiernos deberían tomar acciones para reevaluar algunos proyectos ferroviarios de alta velocidad ineficientes, sin desalentar la construcción de los mismos en otras regiones. Los autores creen que esto no sólo es importante para China, sino también para muchos otros países con proyectos de ferrocarriles de alta velocidad.

Este estudio desarrolla un método razonable de evaluación de la contribución del ferrocarril de alta velocidad, en el desarrollo de la economías regionales y turísticas. Usando este método, este estudio confirma que el ferrocarril de alta velocidad añade impactos positivos en el desarrollo regional.

The causes of high-speed railway failures are complex, and it is difficult to quantitatively and accurately describe safety evaluation. The purpose of this paper is to construct a model to ensure the safety of high-speed railway operations.

The authors construct a high-speed railway operation safety evaluation index system from four aspects: personnel, equipment, environment and management and analyze the inter-coupling relationship of various safety factors. Based on the evaluation index system, the use of network analytic hierarchy process (ANP) and fuzzy comprehensive evaluation will be used to establish a high-speed railway operation safety evaluation model.

Through the literature investigation and field investigation, combined with high-speed railway safety key points and system composition, 4 first-level indicators and 17 second-level indicators were selected to construct a high-speed railway operation safety evaluation index system. It can be seen from the results that the personnel management system and the signal and control system have the largest weight.

On the basis of establishing an evaluation index system, comprehensively considering the internal coupling relationship between evaluation indexes and the fuzziness of high-speed railway operation safety evaluation, high-speed railway uses ANP fuzzy network analysis method to construct high-speed railway operation, and the safety evaluation model has certain advantages and practicability in the case of the relative lack of high-speed railway operation data and fault data.

This study aims to investigate how opening high-speed railways affects the cost of debt financing based on China's background.

Using panel data on Chinese listed firms from 2008 to 2017, this study constructs a quasi-natural experiment and adopts a difference-in-difference model with multiple time periods to empirically examine the relation between the high-speed railway openings and debt financing cost.

Our results show that opening high-speed railways reduces the cost of debt financing, and this negative correlation is more significant in non-state firms, firms with weaker internal control, and firms that hire non-Big Four auditors. Besides, we explore the impact mechanisms and find that opening high-speed railways improves analyst attention, institutional investor participation, and information disclosure quality, which in turn lowers the cost of debt financing.

The results imply that the opening of high-speed railways helps to alleviate the information asymmetry and adverse selection between firms and creditors and ultimately reduces the cost of corporate debt financing.

This paper can inform firms and stakeholders about the impact of opening high-speed railways on debt financing cost: it improves the information environment, reduces the geographical location restrictions of debt financing, ensures the reasonable pricing of corporate debt, and thus promotes the healthy and sound development of the debt market.

This paper provides theoretical support and empirical evidence for the impact of infrastructure construction on the information environment of the debt market in China, which enriches the research on the “high-speed railway economy.” In addition, as an exogenous event, the opening of high-speed railways instantly shortens the time distance between firms and external stakeholders, which gives us a natural environment to conduct empirical research, thus providing a new perspective for financial research on firms' geographical location.

It is quite universal for high-speed turnouts to be exposed to the wear of the stock rail of the switch rail during the service process. The wear will cause the change of railhead profile and the relative positions of the switch rail and the stock rail, which will directly affect the wheel–rail contact state and wheel load transition when a train passes the turnout and will further impose serious impacts on the safety and stability of train operation. The purpose of this paper is to provide suggestions for wear management of high-speed turnout.

The actual wear characteristics of switch rails of high-speed turnouts in different guiding directions were studied based on the monitoring results on site; the authorized wear limits for the switch rails of high-speed turnout were studied through derailment risk analysis and switch rail strength analysis.

The results show that: the major factor for the service life of a curved switch rail is the lateral wear. The wear characteristics of the curved switch rail of a facing turnout are significantly different from those of a trailing turnout. To be specific, the lateral wear of the curved switch rail mainly occurs in the narrower section at its front end for a trailing turnout, but in the wider section at its rear end when for a facing turnout. The maximum lateral wear of a dismounted switch rail from a trailing turnout is found on the 15-mm wide section and is 3.9 mm, which does not reach the specified limit of 6 mm. For comparison, the lateral wear of a dismounted switch rail from a facing turnout is found from the 35-mm wide section to the full-width section and is greater than 7.5 mm, which exceeds the specified limit. Based on this, in addition to meeting the requirements of maintenance rules, the allowed wear of switch rails of high-speed turnout shall be so that the dangerous area with a tangent angle of wheel profile smaller than 43.6° will not contact the switch rail when the wheel is lifted by 2 mm. Accordingly, the lateral wear limit at the 5-mm wide section of the curved switch rail shall be reduced from 6 mm (as specified) to 3.5 mm.

The work in this paper is of reference significance to the research on the development law of rail wear in high-speed turnout area and the formulation of relevant standards.