高速铁路路基动力学研究进展

高速铁路是各个国家竞相发展的关键交通基础设施,对经济发展和社会进步都具有重要意义。高速铁路有别于传统铁路的最大特点是列车运行速度高,从而对铁路路基的振动和沉降等提出严苛的控制要求,突破传统岩土工程理论和技术范畴,高速铁路路基动力学已经成为铁道工程、岩土工程、结构动力学等多学科交叉的国际前沿和研究热点。文中总结国内外对高速铁路路基动力学的研究进展,重点阐述列车荷载作用下路基动力响应的理论分析模型、路基内部动应力分布特征和随着列车运行速度提高的放大效应、列车运行引起路基循环累积沉降分析方法及控制和修复技术等三个方面,并提出高速铁路路基动力学发展的展望。     

石济客专(73+128+73)m连续梁无缝线路设计方案研究

以石济客运专线工程为例,对连续梁无缝线路的设计方案进行了研究,并对调整设计锁定轨温、提高钢轨强度、限制普速列车速度等方法进行了分析论述,以解决客运专线铁路兼顾普速列车上线运营时大跨连续梁无缝线路设计难题。     

The celebration of superficiality: Chinese architecture since 1979

In Chinese history, 'change' had never been the apt term to describe the 'zeitgeist' of its culture until the last two decades of the twentieth century, when China gradually opened its doors to the outside world. This paper discusses the development of Chinese architecture in the transitional period since 1979. It attempts to create a framework for locating, describing and interpreting Chinese architecture in the 'new era'. However, the notion of architecture will not be taken as an autonomous discursive entity, offering an exhaustive theoretical account. Rather, I see it as an historical genre responding to and defending the historical experience of Chinese society. The strategy is thus to map the most salient developments of the period through a critical reading of the various 'new trends' in Chinese architecture that emerged during the last two decades.     

铁路隧道空气附加阻力及坡度折减系数研究

采用非恒定流理论,提出了隧道空气附加阻力的计算方法,分别推导了列车部分进入隧道、全部进入隧道、部分驶出隧道的空气附加阻力解析计算公式;研究了列车在隧道内不同运行时刻的空气阻力变化规律,并全面阐述了隧道长度、隧道净空断面、列车长度、列车运行速度等因素对隧道空气阻力的影响;分析研究了隧道坡度折减系数与隧道长度、净空断面、机车牵引能力的相关性,得出了大断面隧道的坡度折减很小或无需折减的结论,对长大及特长隧道的选线设计具有极其重要的指导意义。     

寻求节点交通价值与城市功能价值的平衡——探讨国内外高铁车站与机场等交通枢纽地区发展的理论与实践

交通枢纽地区的重要性不仅体现在交通设施本身上，而且体现在交通枢纽对城市经济发展的带动作用，以及对交通枢纽周边地区的规划与土地开发的影响方面。目前随着京沪和沪杭高速铁路的逐步启动，沿线设站城市都意识到高铁对城市的巨大影响，但究竟高铁车站对城市的影响有多大，会带来哪些产业的增长，国内理论研究还比较空白。另外空港城的发展在中国也方兴未艾，到底空港城的未来发展方向在哪里，空港城的发展会带来什幺产业的增长，本文试图结合以上这些问题梳理国内外在交通枢纽地区发展的理论与实践，总结其中的一些规律。     

青藏线西格段增建二线盐湖路基设计

对铁路通过察尔汗盐湖地区地层岩性和不良地质进行分段分析,结合既有盐湖铁路路基设计和运营的经验,确定在国铁Ⅰ级旅客列车设计行车速度为160km／h,预留200km／h标准下增建二线的盐湖铁路路基的地基处理措施、选择路基断面形式、路堤边坡防护形式。     

秦沈客运专线路桥过渡段路基动应力测试分析

简单介绍了高速行驶的列车通过路桥过渡段时造成的危害，以及为了改善行车条件，国内外所采取的维护措旌。对我国第一条时速160km以上的运营线——秦沈铁路客运专线DK46 765．95～DK46 790．95的路桥过渡段路基在高速列车作用下的动应力进行了原位测试，分析了沿路桥过渡段线路纵向的动应力分布规律、列车速度和动应力的关系，以及动应力沿路基深度方向的变化规律等。分析结果认为：沿铁路线纵向动应力随车速的增大，动土压力呈现不同幅度的增加；当车速超过176km／h时，路基动土压力值增加幅度很小，甚至略有降低。动土压力随路基深度的增加衰减很快，并且随着深度的增加，动土压力值和静土压力值越来越接近。     

高速列车振动荷载下大断面隧道结构动力响应分析

随着高速铁路的快速发展,高速列车荷载对大断面隧道结构的影响受到关注。采用激振函数模拟高速列车竖向振动荷载,运用弹塑性有限元方法对大断面隧道结构在列车振动荷载作用下的动响应进行了深入的分析。研究了不同断面形式、车速和阻尼比系数对振动响应的影响,并将结果与小断面隧道进行比较。     

桥梁减振技术的发展与应用

介绍了既有铁路桥梁因横向刚度不足及列车提速致使的横向振动、城市桥梁轨道交通车桥耦合动力振动、大跨度桥梁拉索的风雨激振、轴向流激振等几类桥梁振动减振技术的发展与应用.在铁路桥梁和高架桥梁中,对车桥耦合振动体系,采用被动控制法,安装质量阻尼器,改变桥梁基础结构的型式,进行桥梁减振和降噪.在斜拉桥拉索减振上,主要采用机械减振控制,安装目前较常用的粘性剪切型阻尼器进行减振,介绍了新型的磁流变阻尼器半主动控制法减振技术.这些减振措施在一些实际的桥梁减振中都取得了不错的效果.同时,还阐述了近年来在人行桥梁中新发现的人致桥梁侧向振动的桥梁减振新问题.     

寒区高速铁路隧道温度场模型试验系统的研制及应用

 基于寒区高速铁路隧道温度场研究现状及存在问题,以俄罗斯400 km/h的莫喀高铁隧道防寒保温设计为研究对象,研制不同洞外气温、围岩地温、列车运行速度和运行间隔等条件下寒区高速铁路隧道的温度场模型试验系统。该系统由高速列车模型驱动装置、隧道模型、温度控制装置、测试系统以及列车模型五部分组成：高速列车模型驱动装置采用伺服电机,通过PLC梯形图语言编程技术实现列车模型加速、匀速和减速过程的精确控制;隧道模型主体材料采用有机玻璃,通过法兰、螺栓和密封条连接而成,整个试验过程可视化并兼具美观性,还可根据试验需求通过预留多组螺栓孔实现纵向尺寸的拓展,从而模拟不同长度的隧道;温度控制装置由洞外温度控制装置和围岩地温控制装置构成;测试系统由高灵敏度的温度测试元件、风速测试元件以及数据采集仪构成;列车模型以CHR 380A高速列车为模型蓝本,主体材料采用有机玻璃,原型与模型几何相似比为50∶1。试验结果表明：采用控制变量法,洞外气温每降低5 ℃,洞内气温负温长度平均增加104 m;围岩地温每升高5 ℃,洞内气温负温长度平均减少145 m;列车运行间隔短于15 min的寒区隧道,在防冻保温设计时应考虑列车运行间隔对保温设防长度的影响。     

铁路T型梁横向预应力联结的施工技术

在列车不断提速的背景下,铁路工程施工质量要求也在不断提高。T型梁作为铁路的重要组成部分,使用传统施工方法,稳定性和刚度都不理想。为满足铁路干线提速的要求,文章对铁路 T 型梁横向预应力联接施工技术进行了探讨。     

A multidisciplinary approach for fatigue assessment of a steel–concrete high-speed railway bridge on Sesia river

Steel–concrete composite bridge solutions have been more and more exploited in the new high-speed (HS) lines of European railway networks. New design solutions, introduced during a period of quick expansion for railway networks, amplified open problems related to dynamic effects, train–bridge interaction phenomena, fatigue loadings, structural modelling, fatigue life and comfort. In this article, results obtained by long-term dynamic monitoring of Sesia viaduct, a medium span double-box composite bridge of the new Italian HS network, are described and analysed. Structural modal properties were determined in order to evaluate the real-time dynamic behaviour and its correlation with environmental conditions. A suitable numerical procedure was then implemented in order to identify typology, length and velocity of trains crossing the bridge, to evaluate the intensity of deck vertical accelerations as a function of train speed and to obtain a reliable evaluation of real traffic spectra. A final fatigue assessment on welded connections was executed evaluating fatigue spectra by the aforementioned real traffic spectra and assuming S–N curves obtained by suitably executed experimental tests.     

移动荷载作用下大跨度铁路斜拉桥纵向共振机理

列车荷载作用下铁路斜拉桥将在不同方向上发生振动,列车竖向荷载作用下导致的主梁纵向振动将影响道床稳定性和伸缩装置的使用,甚至影响行车安全性和舒适性。采用等效纵向荷载研究移动荷载作用下斜拉桥纵向振动机理,推导纵向共振速度估算公式。以一大跨度铁路斜拉桥为实例,分析了不同速度的移动荷载作用下结构动力响应。结果表明,当移动荷载速度与估算纵向共振速度接近时,移动荷载通过桥梁时的纵向加载频率与桥梁一阶纵向振动频率接近,斜拉桥发生纵向共振现象,主梁和桥塔动力响应显著增大。     

Twim: A MATLAB toolbox for real-time evaluation and monitoring of traffic loads on railway bridges

This paper describes Twim, a toolbox written in the MATLAB computer language. Twim is designed for monitoring bridge behaviour during train passages as well as for performing Bridge Weigh-In-Motion of railway traffic, both in real-time and offline. The algorithms calculate the static bogie loads and bogie distances, as well as the speed and acceleration of the train. Twim also includes visualization functions, automatic identification of known locomotives and an auto-calibration that uses locomotives with known bogie loads. The algorithms used place specific requirements on both the bridge type and the instrumentation of the bridge. These requirements are explained in the paper. The instrumentation of several bridges is described, and some of the interesting results gained through this instrumentation are presented.     

Experimental study on dynamic load magnification factor for ballastless track-subgrade of high-speed railway

The magnitude of dynamic load produced by high-speed trains depends on many factors, of which train speed is the most critical one. However, it is quite difficult to determine the effect of train speed on dynamic load using the theoretical methods due to the complexity of the interaction between vehicle and track-subgrade. Thus large-scale model test has gradually become an important approach for studying dynamic responses of ballastless track-subgrade of high-speed railway. In this study, a full-scale model of ballastless track-subgrade was constructed in accordance with the design and construction standards for Shanghai–Nanjing intercity high-speed railway line firstly. Then, the dynamic strain of slab and the dynamic earth pressure of subgrade were measured by conducting single wheel axle excitation test. In addition, the relationship between the dynamic load magnification factor (DLF) and the train speed was obtained. Finally, the DLF of track-subgrade under different train speeds was proposed, similar to that given by German Railway Standard.     

线路参数对高速车辆曲线通过性能的影响

针对铁道行业中的车辆曲线通过问题,运用SIMPACK虚拟样机技术,建立了高速车辆-轨道动力学仿真模型,对我国60kg/m钢轨断面及LM型车轮踏面进行了开发.针对高速铁路和客运专线,探讨了在车辆速度为200km/h的条件下,曲线半径、超高、缓和曲线长和轨底坡等线路参数对车辆安全性及舒适性的影响.对今后我国高速铁路及客运专线的修建具有一定的指导意义.     

高速下过渡段路基动响应特性研究

通过现场实测,对秦沈客运专线动力分散型机车在某路桥过渡段高速行车条件下的动响应(动应力、动应变)规律进行了研究。研究表明:路基最大动响应曲线与平均动响应曲线变化趋势相同;对于相同行车速度,纵向(沿线路基床水平方向上)动响应曲线呈"V"形变化、动响应增量曲线呈不规则"N"形变化,而垂向(与地面铅垂方向上)则是随深度的增加动响应呈衰减趋势,并且在基床面浅处(0.6m左右)衰减幅度较大;纵向、垂向上的动响应都有随车速提高而减小的趋势,并且其减小幅度与车速高低紧密相关。同时,提出了预测过渡段路基动响应变化趋势的列车轴重变化系数计算公式,以及"超高"填筑路基减小过渡段沉降差值和动响应的设计思路,研究结果为高速铁路过渡段的设计与施工提供了重要基础。     

Vibration of railway bridges under a moving train by using bridge-track-vehicle element

During the last two decades, much attention has been paid to various vibration problems associated with railways. They include the dynamic response of railway bridges and railway tracks at grade under the action of moving trains. However, studies on the role of track structures on the vibration of railway bridges are rather limited. In this paper, a new element called bridge-track-vehicle element is proposed for investigating the interactions among a moving train, and its supporting railway track structure and bridge structure. The moving train is modelled as a series of two-degree-of-freedom mass-spring-damper systems at the axle locations. A bridge-track-vehicle element consists of vehicles modelled as mass-spring-damper systems, an upper beam element to model the rails and a lower beam element to model the bridge deck. The two beam elements are interconnected by a series of springs and dampers to model the rail bed. The investigation shows that the effect of track structure on the dynamic response of bridge structure is insignificant. However, the effect of the bridge structure on the dynamic response of the track structure is considerable.     

Erdbautechnische Untersuchungen zur Qualitätssicherung der 1000 km langen Hochgeschwindigkeitsstrecke Wuhan–Guangzhou

Technical research on the earthwork quality control for the 1000km long high speed railway line Wuhan–Guangzhou. For the earthwork quality control of the 1000km long high speed railway line Wuhan–Guangzhou (WGPDL) in China, lots of soil mechanical investigations have been carried out. In this procedure, not only Chinese codes, but also German standards and experience for the construction of high speed railway lines have been taken into consideration. In this paper, the results of suitability tests for a natural filling material in reference to durability under defined actions are exemplarily illustrated. Then, the laboratory and in‐situ results of comparative studies on the test parameters of density and stiffness are given for four chosen filling materials. These research results have been used as an essential basis for the quality control of earthworks in WGPDL.     

试论中国大型高铁枢纽的发展趋势

本文结合铁路客运的发展历程,将大型铁路客运站的建设分为两个阶段、三种类型,即普速铁路时期的门户车站、高铁时期的交通综合体和城市综合体,并从换乘空间功能角度,概括了大型高铁综合交通枢纽的四项基本特征,同时,从交通设施与城市相互关系的角度反思目前中国交通综合体型高铁枢纽存在的问题,并针对上述问题,分析介绍国外高铁枢纽采用的城市综合体建设模式,以期为我国今后高铁枢纽的发展提供参考。