客运专线隧道大断面软弱围岩施工存在的问题及对策

 随着铁路客运专线的大规模发展，将会不断遇到软弱围岩大断面隧道的施工问题，针对目前我国客运专线隧道大断面软弱围岩施工的现状，分析了施工中存在的主要技术问题，并提出了相应的对策,以期对目前在建和拟建的隧道工程提供参考和借鉴。     

Railway wheel-flat and rail surface defect modelling and analysis by time–frequency techniques

Damage to the surface of railway wheels and rails commonly occurs in most railways. If not detected, it can result in the rapid deterioration and possible failure of rolling stock and infrastructure components causing higher maintenance costs. This paper presents an investigation into the modelling and simulation of wheel-flat and rail surface defects. A simplified mathematical model was developed and a series of experiments were carried out on a roller rig. The time–frequency analysis is a useful tool for identifying the content of a signal in the frequency domain without losing information about its time domain characteristics. Because of this, it is widely used for dynamic system analysis and condition monitoring and has been used in this paper for the detection of wheel flats and rail surface defects. Three commonly used time–frequency analysis techniques: Short-Time Fourier Transform, Wigner–Ville transform and wavelet transform were investigated in this work.     

挂篮施工上跨城际铁路防护棚架设计

针对高速列车行驶的上空挂篮施工存在的安全隐患难题,采用了防护棚架的设计方案,成功地分离了列车与上跨施工的界面,形成了一个全封闭的施工空间.设计中重点考虑了高速列车通过瞬间产生的气动压力和气动吸力对棚架产生的影响,对各种工况条件下各结构受力状态进行了稳定性验算.     

大瑞铁路老红坡隧道穿越接触带单侧涌泥处理技术

大瑞铁路老红坡隧道穿越可溶岩与非可溶岩接触带施工单侧发生涌泥大变形地质灾害。通过分析变形开裂及地质成因，正洞内采用迂回导坑方案探明涌泥体范围，采用洞内扩挖工作洞室，在隧道单侧轮廓外施作超前水平注浆+高压水平旋喷桩加固及超前水平长大管棚的方案进行处理，并对该段支护及衬砌结构调整加强。依据现场工况，采用三台阶法分部、分段拆换作业，在钢架拱脚增设临时仰拱或临时横撑控制收敛变形，及时施作格栅钢架模筑衬砌，变形稳定后再施作永久二次衬砌。该技术在大瑞铁路老红坡隧道单侧突泥涌水地质灾害处治施工实践中得到了成功应用，取得了良好效果。     

路基是有生命力的结构物——我国高速铁路路基建设取得的成就和需要继续解决的问题

系统归纳总结我国高速铁路路基技术体系形成、发展、完善的历程和高速铁路路基建设10年来在地基处理、路基结构层设计和填筑、路堤式路堑、过渡段、路基边坡支挡防护和防排水、路基结构与附属电缆沟槽和接触网支柱等基础的系统集成、沉降变形观测与评估等方面变革和发展取得的成就,指出正是高速铁路对路基工程刚度和变形的严苛要求,促进了我国高速铁路路基技术的革命性变革和不断进步,强化了路基结构物的建造理念,凝聚了路基结构物的生命力;同时,在非饱和土、膨胀土(岩)等方面阐释路基建设过程中仍需继续研究解决的问题。希冀本文有助于我国高速铁路路基技术体系的不断完善、创新发展,进一步提升我国高速铁路路基建造水平,增强满足列车安全、高速、舒适运营的生命力。     

双块式无砟轨道轨枕的优化设计研究

针对目前我国双块式无砟轨道轨枕在设计、生产、运输、铺设等过程中存在的一些问题进行探讨和分析，并在此基础上对双块式轨枕进行优化设计，以供我国双块式轨枕的设计作参考。     

京沪高速铁路制梁场双层存梁设计研究

结合京沪高速铁路制梁场优化设计实践，对双层存梁方案适用的前提条件、双层存梁的平面布置形式以及存梁区有关周期节点时间等作了较深入的分析探讨；对双层存梁设计的基本思路、方法作了简要阐述。双层存梁方案研究的意义，在于进一步减少临时工程占地，节约土地资源。     

Wear simulation for the centre plate arrangement of a freight car

The bodies of many railway freight cars in many countries of the world are coupled to the running gear by means of a body centre plate that makes a friction pair with a centre bowl. During motion, the bogie is rotated and moved with respect to the car body. This leads to wear on the contact surfaces. Lubrication is inexpedient in this case because the friction forces damp the vibrations (so-called bogie hunting) during motion. Usually, centre plates exhibit noticeable wear after two years of operation. Reducing wear requires knowing details of the wear process which, in turn, requires computer simulation of freight car motion for an operation period of 10–15 years. The purpose of this paper is to develop a universal method for wear simulation of friction pairs that could be used, in particular, for the centre plate of a freight car.     

田德铁路小龙煤矿采空区的地质选线

田德铁路位于桂西南右江盆地及岩溶峰林洼地区，其中线路在CIK6＋200-CIK7＋000之间横穿小龙煤矿中部，由于采空区的不断下沉和地表变形，使过境公路及周围建筑物产生了较为严重的病害，线路在小龙村地段存在横穿煤矿方案和绕行方案的比选问题。通过对小龙煤矿采空区地质状况、地表沉降及稳定性的分析与评价，推荐绕行方案（CK方案）为贯通方案。     

青藏高原铁路客车电气系统设计

文章从安全性和可靠性的角度出发,指出了青藏高原铁路客车电气系统需要解决的难题,介绍了电气系统及设备所采取的针对性措施以及系统控制与防护措施。