隧道内支承块空吊对钢轨竖向位移影响

为研究隧道内列车荷载下弹性支承块空吊对钢轨竖向位移的影响,基于银洞坡和定水坝隧道现场实测数据,建立考虑支承块空吊的力学模型,分析连续1~3块支承块空吊情况下钢轨竖向位移的超限情况。实测和研究结果表明:隧道内实测的空吊位置和量值具有不确定性特征,空吊现象引起的钢轨竖向位移有超过安全指标的情况;单块支承块空吊值在10 mm以下,钢轨竖向位移不出现超限情况,当连续2块或连续3块支承块空吊量大于3 mm时,钢轨竖向位移出现超限情况,对于隧道内复杂的支承块空吊病害,建议控制空吊量在3 mm以内,同时应尽量避免连续空吊情况。     

基于机器视觉的钢轨表面检测光学模型的研究

在机器视觉的检测中,图像是整个系统中最重要的原始数据,其质量决定了后期图像处理的效果和速度。为探讨高质量图像的采集,提出一种基于线阵CCD相机和线阵光源的钢轨表面缺陷检测的光学理论模型,分析线阵CCD采集系统中振动模糊的原因,推导出图像灰度值与系统振动幅度和缺陷深度的关系,研究光源照射角度和相机拍摄角度对图像灰度和缺陷区域对比度的影响,并通过实验验证模型的合理性。结果表明:缺陷区域图像灰度值随着钢轨表面缺陷深度增大而降低,采用较低的光源照射角度可增大缺陷与背景的对比度,突出缺陷特征便于后期图像处理的缺陷识别。     

城际轨道交通信号系统设计方案探讨

针对城际轨道交通信号系统工程,讨论了信号系统适用的几种方案。考虑到工程实际条件,从运营需求、系统功能、实施难度等方面对几种信号系统方案进行了比选讨论,对城际轨道交通信号系统的建设具有一定的参考意义。     

城市轨道交通诱增客流量预测分析

介绍了城市轨道交通诱增客流量的定义及现有的预测模型,并指出其在应用中存在的问题。分析了城市轨道交通诱增客流量预测的难点,指出城市发展、常规公交、票价、线网规模、出行成本及交通政策是预测诱增交通客流量中需要考虑的主要因素。给出了城市轨道交通诱增交通量预测框架。     

Rail travel and the Leisure market in great Britain

The purpose of this paper is to examine the factors influencing and inducing leisure travel; to convey the sensitivity of rail travel receipts to the performance of the economy and more particularly family and personal disposable incomes; to examine the potential for further market research; and finally, to determine ways and means of attracting marginal revenue in the sustainable recreation/tourism sphere to a major public sector asset.

The paper focuses on leisure marketing by Britain's national railway corporation, British Rail (BR), and the relevant activities of its three passenger business sectors: Network SouthEast (NSE), which operates regional and local services in London and the South East (though not the London ‘tube’ system); Regional Railways, which operates regional and local services elsewhere in Great Britain; and InterCity, which operates the long distance express services.

The paper reviews BR's fares promotions of recent years and in particular draws on some examples taken from Regional Railways. This sector is now the only business of British Rail which in principle is subject to a significant public grant, to meet the obligation of a minimum level of service on social grounds. Of the other two passenger businesses, Network SouthEast receives a grant but the current intention is that it should operate on a breakeven basis from the 1992/93 financial year; InterCity runs on a purely commercial basis.     

钢轨移动闪光焊接接头软化问题的研究

通过硬度测定、热影响区宏观形貌和微观组织观察,对移动闪光焊接接头软化问题进行了试验研究。研究结果表明,焊接接头软化区与正火热影响区相对应,软化区内的微观组织为粒状珠光体;接头软化是由于正火热处理加热不足所致。同时,提出预防焊接接头软化问题的措施。     

基于拉姆塞定价模型的天津地铁价格定价研究

目前国内的地铁票价大多采取单一票价制或者计程票价制，虽然这在票价上体现了公平，但是，如果利用地铁票价的价格杠杆来引导客流，就可以进一步提高公共交通系统的效率，改善社会福利。研究认为，应用拉姆塞定价原理采用高峰定价法可以实现这种效果。此文从经典的最优拥挤定价理论出发，分析城市道路拥挤定价中的交通需求的变化和在拥挤定价条件下的交通需求预测问题，探讨拥挤定价的收费标准对出行方式选择和需求的弹性，为该高峰分时段定价政策的实施奠定理论基础。     

城轨高架桥上无缝线路设计的关键技术

介绍并分析了城市轨道交通高架桥上无缝线路设计的国内外研究现状及关键技术问题,包括:计算模型和方法,线路纵向阻力、桥墩线刚度的确定,曲线桥上线路横向力的计算,降低钢轨附加纵向力的措施等.提出了解决这些关键技术问题的基本思路、研究方法和技术措施.     

京通线钢轨磨耗与防治措施

京通线西部曲线钢轨磨耗一直是困扰维修生产的难题，频繁地更换钢轨会增加维修成本，若磨耗钢轨不能及时更换又会给行车安全带来隐患。2002年京通西部线开始大修，对部分曲线采取了减磨措施。通过现场数据监测．减磨效果明显。。     

Distance and time in intermodal goods transport networks in Europe: A generic approach

This paper is about distance and time as factors of competitiveness of intermodal transport. It reviews the relevance of the factors, evaluates time models in practice, compares network distances and times in alternative bundling networks with geometrically varied layouts, and points out how these networks perform in terms of vehicle scale, frequency and door-to-door time. The analysis focuses on intermodal transport in Europe, especially intermodal rail transport, but is in search for generic conclusions. The paper does not incorporate the distance and time results in cost models, and draws conclusions for transport innovation, wherever this is possible without cost modelling. For instance, the feature vehicle scale, an important factor of transport costs, is analysed and discussed.Distance and time are important factors of competitiveness of intermodal transport. They generate (direct) vehicle costs and – via transport quality – indirect costs to the customers. Clearly direct costs/prices are the most important performance of the intermodal transport system. The relevance of quality performances is less clarified. Customers emphasise the importance of a good match between the transport and the logistic system. In this framework (time) reliability is valued high. Often transport time, arrival and departure times, and frequency have a lower priority. But such conclusions can hardy be generalised. The range of valuations reflects the heterogeneity of situations. Some lack of clarity is obviously due to overlapping definitions of different performance types.The following parts of the paper are about two central fields of network design, which have a large impact on transport costs and quality, namely the design of vehicle roundtrips (and acceleration of transport speed) and the choice of bundling type: do vehicles provide direct services or run in what we call complex bundling networks? An example is the hub-and-spoke network. The objective of complex bundling is to increase vehicle scale and/or transport frequency even if network volumes are restricted. Complex bundling requires intermediate nodes for the exchange of load units. Examples of complex bundling networks are the hub-and-spoke network or the line network.Roundtrip and bundling design are interrelated policy fields: an acceleration of the roundtrip speed, often desirable from the cost point of view, can often only be carried out customer friendly, if the transport frequency is increased. But often the flow size is not sufficient for a higher frequency. Then a change of bundling model can be an outcome.Complex bundling networks are known to have longer average distances and times, the latter also due to the presence of additional intermediate exchange nodes. However, this disadvantage is – inside the limits of maximal vehicle sizes – overruled by the advantage of a restricted number of network links. Therefore generally, complex bundling networks have shorter total vehicle distances and times. This expression of economies of scale implies lower vehicle costs per load unit.The last part of the paper presents door-to-door times of load units of complex bundling networks and compares them with unimodal road transport. The times of complex bundling networks are larger than that of networks with direct connections, but nevertheless competitive with unimodal road transport, except for short distances.