高速铁路钢轨廓形打磨质量评估方法及应用

在借鉴国外钢轨廓形打磨质量指数(GQI)的基础上,结合《高速铁路钢轨打磨管理办法》中的廓形验收标准,提出基于钢轨廓形打磨质量指数和廓形偏差曲线的评估方法。首先根据砂轮打磨角度对钢轨廓形打磨区域进行划分,通过德尔菲法确定各个区域的廓形权重系数,然后根据钢轨廓形与目标廓形的偏差,提出GQI值计算公式,最后辅以廓形偏差曲线,评估钢轨廓形打磨质量;并进行现场应用分析。结果表明:采用的评估方法不仅可对钢轨打磨质量进行评估,而且可对钢轨廓形状态是否会导致动车组异常振动进行预测,进而给出合理的钢轨打磨建议;提出的GQI计算公式既能评判钢轨打磨廓形是否达到要求,又能量化打磨廓形与目标廓形吻合程度;GQI值大于70且变化范围较小,可有效减轻或消除动车组构架报警、晃车等异常振动。     

枢纽机场联通轨道交通的对策和建议

本文以问题导向和需求导向为出发点,紧密围绕我国千万级枢纽机场连接轨道交通的发展现状,聚焦在规划设计、建设实施、运营管理等方面存在的问题,结合千万级枢纽机场的轨道集疏运的需求分析,提出我国枢纽机场联通轨道交通的对策和建议,为我国枢纽机场轨道集疏运系统的高质量发展提供理论支撑。     

轨道交通车-地通信无线局域网技术应用

无线局域网技术方案在覆盖、网络、系统接入等方面具有独特优势。本文针对轨道交通车-地通信无线局域网技术应用的优缺点,以及技术方案设计进行阐述,指出无线局域网技术还将在轨道交通车-地通信中具有应用价值。     

A Bayesian model to assess rail track geometry degradation through its life-cycle

One of the major drawbacks in rail track investments is the high level of uncertainty in maintenance, renewal and unavailability costs for the Infrastructure Managers (IM) during the life-cycle of the infrastructure. Above all, rail track geometry degradation is responsible for the greatest part of railway infrastructure maintenance costs. Some approaches have been tried to control the uncertainty associated with rail track geometry degradation at the design stage, though little progress has improved the investors' confidence. Moreover, many studies on rail track life-cycle cost modelling tend to forget the dynamic perspective in uncertainty assessments and do not quantify the expected reduction of the uncertainty associated with degradation parameters as more inspection data is collected after operation starts.     

浅析港口堆场轨道扣件系统的选型

基于对港口工程堆场轨道扣件系统的使用现状及存在问题的分析,针对港口工程堆场常用的几种扣件系统进行比较,从适用性、经济性和耐久性等方面出发,针对不同轨道基础形式提出扣件选型的方法和使用中的注意事项,为类似港口工程的堆场扣件选型提供参考.     

Are railways really that bad? An evaluation of rail systems performance in Europe with a focus on passenger rail

With a large number of railway development projects in Europe and worldwide, which once completed will be serving rail passengers of the future, this paper aims to take a step back and evaluate current railway systems performance. The objectives are to compare statistical data on various passenger-related parameters of the railway system in a number of selected European countries and draw conclusions on the level of their performance when compared to the European average.Analyses of publically available statistical data, extracted from the Eurostat service at a European level will allow for a comparison of various indicators which influence the performance of the railway systems from an infrastructure and operational perspectives. The analyses will also allow identifying key performance indicators for the accurate assessment of the rail systems.The paper will highlight case studies for various parameters which are important to stakeholders of the railways, including infrastructure managers, rail operators, policy makers and the end users. This knowledge will be to the benefit of today’s railway industry as well as the rail systems of the future, as it will show trends drew upon existing data which might continue in the future.     

Preference heterogeneity in mode choice based on a nationwide survey with a focus on urban rail

The provision of efficient and effective urban public transport and transport policy requires a deep understanding of the factors influencing urban travellers’ choice of travel mode. The majority of existing literature reports on the results from single cities. This study presents the results of a nationwide travel survey implemented to examine multiple modes of urban passenger transport across five mainland state capitals in Australia, with a focus of urban rail. The study aims to explore differences in mode choices among surveyed travellers sampled from the five cities by accounting for two types of factors: service quality and features of public transport, and socio demographic characteristics. A stated preference approach is adopted to elicit people’s valuation of specified mode-choice related factors and their willingness to pay. In particular, the availabilities of wireless and laptop stations – two factors rarely examined in the literature, were also considered in the SP survey. The survey data were analysed using mixed logit models. To test for preference heterogeneity, socio-demographic factors were interacted with random parameters, and their influences on marginal utilities simulated. The analysis reveals that intercity differences, user group status, gender, income, and trip purposes partially explain observed preference heterogeneity.     

上海机场联络线车辆选型分析

机场联络线是上海市域轨道交通线网中东西向的骨干线,起自虹桥枢纽,终于铁路上海东站,主线联通“两场两站”,旅行时间目标为将虹桥和浦东两大综合交通枢纽之间的运行时间控制在40 min内,以进一步整合航空、铁路等对外交通资源。结合上海机场联络线线路长度、车站分布及时间目标值要求进行分析比较,该线采用120~200 km/h速度目标值时其适应性较好。结合该线的功能定位、敷设方式、乘坐舒适度、时间目标值、车辆技术成熟度等多种因素综合考虑分析,推荐该线车辆采用AC 25 kV供电制式、设计速度为160 km/h的动车组。     

Passengers’ valuations of train seating layout,position and occupancy

The layout of seating within train carriages, of which there are numerous possibilities, and also the occupancy of that seating can be expected to impact on passengers’ experiences of a train journey. However, there is very little evidence on how rail passengers value different seating experiences. On the back of exploratory research, and including attitudinal evidence, this paper provides significant and original insights into rail passengers’ preferences in this area. The primary evidence base is a Stated Preference experiment, complemented by a novel Revealed Preference exercise that uses CCTV footage to observe where rail passengers prefer to sit.The valuations, expressed as travel time multipliers, obtained from the Stated Preference exercise are generally plausible and exhibit a wide range according to the precise seating configuration, the occupancy level and the seating position within a layout. The innovative Revealed Preference analysis provides an encouraging degree of support to the Stated Preference results which, reassuringly, can themselves be reconciled with related valuations widely used in the railway industry in Britain and also the findings of the exploratory and attitudinal research. Whilst we are interested here solely in obtaining valuations, we demonstrate how they can be used in demand forecasting.     

An integrated metro operation optimization to minimize energy consumption

Energy efficient techniques are receiving increasing attention because of rising energy prices and environmental concerns. Railways, along with other transport modes, are facing increasing pressure to provide more intelligent and efficient power management strategies.This paper presents an integrated optimization method for metro operation to minimize whole day substation energy consumption by calculating the most appropriate train trajectory (driving speed profile) and timetable configuration. A train trajectory optimization algorithm and timetable optimization algorithm are developed specifically for the study. The train operation performance is affected by a number of different systems that are closely interlinked. Therefore, an integrated optimization process is introduced to obtain the optimal results accurately and efficiently.The results show that, by using the optimal train trajectory and timetable, the substation energy consumption and load can be significantly reduced, thereby improving the system performance and stability. This also has the effect of reducing substation investment costs for new metros.