地铁提速对减振垫浮置板轨道振动特征的影响分析

为研究地铁列车提速对减振垫浮置板轨道的振动特征的影响,对比分析地铁列车行车速度为80 km/h和120 km/h工况下减振垫浮置板轨道时域和频域的实测结果。分析结果表明:行车速度对减振垫浮置板轨道结构垂向位移的影响不大;行车速度为120 km/h的工况下钢轨、浮置板、隧道的振动加速度1/3倍频程的峰值较行车速度为80 km/h的工况下的峰值分别有6.2、2.8、0.5 dB的增大;分频段分析各测点振动加速度综合振级,结果显示:在0~20 Hz与20~80 Hz频段内,只有钢轨的振动加速度综合振级增长超过5%,浮置板与隧道振级变化均小于2.5%,在80~120 km/h速度范围内,行车速度的提高对减振垫浮置板轨道隧道振动的影响并不明显。     

铁路直通货物列车技术站接续方案优化研究

在研究铁路货物列车技术站接续特点的基础上,对直通货物列车接续方案选择方法进行了相关扩展并建立了相应的优化模型,通过分析得出各模型均可以采用最小费用流算法进行求解。设计算例的结果表明,各种扩展方法对于优化技术站直通货物列车的接续是有效的。     

中欧班列乌鲁木齐集结中心规划方案研究

为了解决中欧班列存在的主要问题,保障中欧班列长期健康运行,通过分析中欧班列及既有集结中心存在的问题,结合市场需求,确定中欧班列乌鲁木齐集结中心的功能定位。依托中欧班列发展规划,利用增长率法进行运量预测。从枢纽规划布局、铁路场站功能定位对乌鲁木齐枢纽内的4个站点进行综合比较分析,推荐出合理的选址。并结合功能定位、班列集装箱集结种类进行功能分区和布局规划,形成集铁路区、整车集结仓储、海关监管及综合服务于一体的班列集结中心。研究了贯通式布置方案及尽头式布置方案,通过综合比选推荐运输组织灵活、效率较高的贯通式布置方案。     

武汉局集团公司快运货物班列运营策略探讨

快运货物班列作为铁路货运的新产品,自开行以来以其提高货运资源利用率,有效带动周边区域经济得到全社会的广泛赞誉。为加快推进铁路货运市场化改革,进一步提升快运货物班列的市场竞争力,以武汉局集团公司为例,在阐述快运货物班列运输的现状的基础上,对目前存在的问题进行深入分析,结合武汉局集团公司快运货运班列运营特色,针对目前武汉局集团公司快运货物班列存在的问题,探讨快运货物班列运营策略,为快运货物班列产品有效打入货运市场,提升铁路货运竞争力提供决策参考。     

Scheduling freight trains traveling on complex networks

In the US, freight railways are one of the major means to transport goods from ports to inland destinations. According to the Association of American Railroad’s study, rail companies move more than 40% of the nation’s total freight. Given the fact that the freight railway industry is already running without much excess capacity, better planning and scheduling tools are needed to effectively manage the scarce resources, in order to cope with the rapidly increasing demand for railway transportation. This research develops optimization-based approaches for scheduling of freight trains. Two mathematical formulations of the scheduling problem are first introduced. One assumes the path of each train, which is the track segments each train uses, is given and the other one relaxes this assumption. Several heuristics based on mixtures of the two formulations are proposed. The proposed algorithms are able to outperform two existing heuristics, namely a simple look-ahead greedy heuristic and a global neighborhood search algorithm, in terms of railway total train delay. For large networks, two algorithms based on the idea of decomposition are developed and are shown to significantly outperform two existing algorithms.     

An analysis of the methods used to calculate the emissions of rolling stock in the UK

The aim of this paper is to analyse and compare the methods used for calculating emissions of UK rolling stock based on their type and mode of operation. The three modes under comparison were; diesel, electric and bi-mode. As well as comparing these three modes of operation, a comparison between Conventional, Freight and High Speed Rail was made. Alternate fuels were considered for diesel and bi-mode locomotives and compared based on their environmental impact. The emissions of trains were studied using three methods. Specifically, the three chosen methods were used to calculate the emissions of each train and a comparison of these methods was made. In the current UK energy climate, diesel trains emit less emissions than electric trains when factoring in mechanical and air resistances. Bi-mode trains have their place in the UK network but with electrification of the network currently in place, this mode of operation will become redundant in the near future. High Speed Rail, although time efficient, releases high emissions due to energy consumption increasing with the square of speed. Alternative fuels, such as biodiesel, should be a consideration for the future of rail, as emissions fall dramatically with content of biodiesel in fuel blends.