沙特干旱地区无缝线路应力放散施工技术

无缝线路应力放散是轨道工程施工中的重要环节,在炎热干旱气候下,使无缝线路应力放散均匀,实际锁定轨温控制在设计锁定轨温范围之内,在施工中至关重要。应力放散就是在设计锁定轨温范围内,将无缝线路全长扣件,防爬器等全部松开,让它自由伸缩,把钢轨内部的温度应力全部放散掉然后再重新锁定线路。以沙特南北铁路CTW200标段为例,介绍无缝线路应力放散施工技术。     

关于桥梁无缝线路纵向附加力计算方法的研究创新

随着我国铁路客运和高速铁路的兴建,有线提速和城市轨道的发展,区间和跨区无缝线路已经成为轨道结构的主要形式。桥上无缝线路梁轨相互作用是轨道工程的关键技术。本文以梁轨相互作用原理为基础,建立了纵向附加力计算有限元模型,并与纵向附加力微分方程求解法、广义变分原理以及有限单元法计算进行结果比较,表明采用的有限元计算是合理的。     

钢轨伤损原因与防治对策

钢轨伤损的主要原因是曲线超高设置不合理，轨道刚度和轨低坡曲线几何状态、制造工艺不良与养护跟不上而造成；改进工艺提高耐磨性，加快改造小半径曲线，大力发展无缝线路，加强综合养护和防治监控。     

使用600m无缝轨道研究与实践

本介绍如何解决600mQU120FQ无缝轨道在一年四季中热胀冷缩问题。采用特殊扣件，使每米阻力≤1200N，使钢轨的伸缩都集中在两端，以保证无缝轨的温度应力不传递给轨梁及柱子，降低了轮体及轨道夹板的损耗。     

FA203A型梳棉机曲轨的改进

青岛纺机生产的FA203A型梳棉机,在使用过程中,经常发现由于盖板曲轨同曲轨密封边条之间夹杂飞花。通常处理该问题的方法为先检查固定盖板与锡林,大漏底与锡林,盖板与锡林等之间是否噎车。如以上都无问题,最后才将问题锁定在锡林与曲轨同曲轨密封边条之间飞花造成锡林噎车。该问题的解决必须要将所有移动盖板拆下后才能将杂持飞花清理,要耗费至少四名保全工半天时间。该问题的存在将影响梳棉机的正常运转。由于锡林噎车,增加保全工的劳动量,打乱正常工作程序;由于经常对分梳元件进行拆卸,易造成分梳隔距不准确,从而影响分梳效果;锡林运转不…     

高架桥吊使用600m无缝轨道研究与实践

本文介绍如何解决600m QU120无缝轨道在一年四季中热胀冷缩问题。采用特殊扣件,使每米阻力≤1200N,使钢轨的伸缩都集中在两端,以保证无缝轨的温度应力不传递给轨梁及柱子。降低了轮体及轨道夹板的损耗。     

10千伏线路窃电用户快速锁定工作法

正传统10千伏线损管理习惯于发现线损率高以后利用人工查询系统数据,再现场逐台排查分析,费时费力且做不到实时发现处理。文章从拓宽窃电排查的思路着手,探索10千伏高损线路窃电用户快速锁定工作法,降低10千伏线路线损,实现提质增效。     

冶金坡道线路的升级改造与应用

冶金线路以其特有的属性常存在长坡道、小半径的现状,而坡度较大易造成钢轨爬行,轨缝扩大,进而产生顽固病害。本项目创新地应用新的改造思路,从源头解决了坡道线路爬行等问题。     

铁路机电设备电气线路故障及改进

以朝叶铁路1标项目铺轨工区应用的焊轨车为例,研究铁路机电设备电气线路故障,分析机电设备电气线路运行顺畅的重要性,对其所产生的各类故障问题进行处理,使机电设备可以始终维持一个稳定的运行状态。     

共轨系统助力节油车型 博世在华力推本土化战略

在刚刚结束的第二届中国国际卡车节油大赛上,从获奖名单中可以看到,几乎所有的获奖车型都有一个相同之处,那就是无一例外地选择了共轨系统。共轨系统助节油共轨系统如何帮助整车实现节油?博世柴油股份有限公司高级经理顾志华给出了解答。"共轨系统能够实现节     

基于长短期记忆网络的轨道交通短期OD客流量预测

为了更准确地掌握轨道交通客流在线网中的时空分布,更高效地匹配客流需求与运输能力,实现提高轨道交通运输效率、改善运营服务质量的目的,提出了一种基于长短期记忆网络的短期OD(交通起止点)客流量预测方法。以历史客流数据为基础,定性分析车站间OD客流量的时空相关性,利用回归分析法定量分析客流影响因素,筛选出运营时刻、运营日特征、最低气温3个时间特征。为提高预测精度,以长短期记忆网络为基础,结合时间特征,为每对起讫点单独构建预测模型,形成了基于长短期记忆网络的轨道交通短期OD客流量预测模型。以苏州市为例进行验证,结果表明,加入了时间特征的短期OD客流量预测模型较移动平均模型、仅利用历史客流数据训练的基于LSTM网络的短期OD客流量预测模型,预测结果与真实值之间的误差降低了6.27%～8.58%,所提出的方法和模型可为轨道交通运营部门制定列车运行计划、组织客运工作提供更准确的数据资料。     

轨道交通信息化产业链分析

从轨道交通体系结构入手,结合轨道交通信息化产业结构,提出了通信系统产业链、信号产业链、车辆信息化产业链、电力监控产业链、环控与防灾报警产业链、自动售检票产业链、运营管理系统产业链和轨道交通信息化新兴产业链等八大产业链,并对每个产业链进行了深入系统的分析。     

Hedonic Amenity Valuation and Housing Renovations

Hedonic and repeat sales estimators are commonly used to value such important urban amenities as schools, environmental quality and access to transit. Given that property data often omits information on quality differences between same‐aged homes as well as changes in structural attributes over time, researchers must assume that property renovations are uncorrelated with neighborhood amenities. We formally test if this assumption is valid by incorporating detailed data on renovations in Charlotte, North Carolina. We begin by testing how the inclusion of minor and major home improvements influences hedonic and repeat sales indices. Results find limited bias in hedonic indices and that renovated properties are no more likely to be sold than nonrenovated properties. Using the introduction of Charlotte's light rail‐transit system in 2000, we estimate a positive bias of between 1.6% and 19.9% on the capitalized benefits of access to light rail due to omitted information on renovations. Our results show that a number of common data cleaning techniques used to address missing information on structural improvements may worsen this bias.     

Advances in the competitiveness of pan‐European rail freight services: findings from a case study

The European rail freight market is ostensibly a free market where, from 1 January 2007, both incumbent and new‐entrant operators are able to compete on every line and in every European Union country. The main objective of this research paper is to assess the advances in the competitiveness of the pan‐European rail freight services operated by a new‐entrant (private) operator. Its main focus is to assess and contribute to the understanding of the advances towards competitiveness and the future prospects in the open European rail freight market, including dealing with challenges (e.g. dormant and departure of partners, suspension of the project, indistinct roles and responsibilities of operating partners) at different phases of the research, development and service offerings, that will be an important contribution to the Research and Development (R&D) policy and management arena in the Europe rail freight transport sector. The current research applies a case study research approach. The assessment of the rail freight service is performed by conducting two phases: first, a comparison of the progress between first and second year of the REorganisation of Transport networks by advanced RAil freight Concepts (RETRACK) rail freight service, operated by a new entrant and conducted on the corridor between two hubs – Cologne, Germany, and Györ, Hungary, and secondly a comparison of the opinions of customers on the RETRACK service and its competitors. From the comparative study between the first and second years, the study finds that the new‐entrant operator was able to offer an increased number of services by consolidating cargo from satellite connections at both ends of the operational corridor by adopting a pragmatic and flexible approach. The customer satisfaction survey suggests that the new‐entrant operator offered better service in terms of price, transit time, reliability and information flow/management compared to its competitors' services (offered by incumbent rail operators) on the corridor. However, their service was inferior to that of its competitors, in terms of frequency and availability of service. These less‐well performed service factors have improved gradually over time. The study suggests that intra‐rail competition has improved, but that inter‐modal completion is yet to be achieved. The ups and downs of the project provide important lessons for R&D management, academia and policy makers. The study suggests that a pan‐European rail freight service can be efficiently and effectively run by new‐entrant operators, and this will lead to more intra‐modal competition. However, they have yet to achieve competitiveness that will result in a shift of cargo from road to rail by offering an improved service that at least matches the major attributes of road freight service, e.g. price, transit time, door‐to‐door service and working in a collaborative way with other actors.     

模拟井下环境的下井仪器测试系统

介绍了一种模拟井下环境的下井仪器测试系统。该系统可以模拟石油井下环境的温度和压力等，对下井仪器的性能指标进行测试和实验。实际使用和运行结果表明，该系统达到了设计的功能和技术指标要求。     

铁路罐车密闭装车计量系统的运行分析

以济南分公司新上铁路罐车密闭装车计量系统存在的问题出发．阐述铁路罐车密闭装车系统的设计思想和组成：通过分析实际运行过程中仪表比对数据,探讨影响仪表贸易交接准确性的各种因素,提出相应的解决方法,最后通过铁路罐车密闭装车计量系统使用效果,证实该系统可产生明显的经济效益。     

高铁网络抑制城市创新驱动发展——来自FDI的“逆城市化”解释

现有文献鲜有研究高铁开通引发的FDI流动对城市创新究竟存在何种影响效应。本文使用1999~2018年282个地级市的面板数据,构建双重差分模型研究高铁网络对沿线城市创新的影响效应与机理。研究发现:(1)高铁网络对沿线城市的高质量创新能力存在显著的抑制效应,但对应用型创新存在显著的促进效应;(2)高铁网络引发的FDI流动导致沿线城市出现“逆城市化”现象,进而抑制了城市高质量创新驱动发展进程,其解释效力达到30%以上;(3)FDI借助高铁网络流动主要导致高研发强度城市产生了“逆城市化”现象。本文为政府利用高铁网络在全国层面引导FDI合理流动并推动沿线城市高质量创新驱动发展提供了经验数据层面的参考。     

一种基于机器视觉技术的城市轨道交通客流量检测方法

为了准确识别并检测城市轨道交通客流量变化,研究轨道交通客流量的变化规律,以客观图像为研究对象,以机器视觉技术为研究手段,提出了一种新的交通客流检测方法。在对交通客流视频图像进行滤波与增强后,利用Canny边缘帧差法从预处理图像中获取完整的运动目标轮廓。同时,利用AdaBoost检测算法构建的强分类器完成乘客头部的检测,并通过双线差值算法消除视频图像中不同位置尺寸所产生的误检框,实现对目标的跟踪与记载,完成客流量的统计。结果表明,该方法在交通客流量的检测中准确率高于90%。检测方法对提高城市轨道交通客流量的检测准确性具有一定的借鉴意义。     

桥式起重机车轮啃轨的研究

综述了桥式起重机车轮啃轨产生的原因,大致有车轮制造、安装,钢结构,轨道安装,驱动系统等几方面原因。针对车轮水平偏斜、垂直偏斜、大车的跨度差、对角线差、轨道的跨度差、直线度、驱动系统同位度等主要技术问题进行了系统的分析与研究,并提出检查和修理方法,从根本上防止啃轨现象的产生。     

潞宁煤业2#煤西翼扩区轨道运输大巷支护原理研究

本文通过对潞宁煤业2#煤西翼扩区轨道运输大巷进行简要介绍并对其煤层和围岩进行了物理力学性能调研分析,得出2#煤西翼扩区轨道运输大巷的顶板和两帮具有不同的围岩特性,进而提出对其轨道运输大巷及煤巷的顶板和两帮宜采用的相应锚杆支护原理。