当前铁路隧道施工亟待解决的若干技术问题

高速铁路隧道工程建设标准高,施工难度大,安全风险高,施工管理要求严格。文章以贵广铁路隧道工程为实例,结合当前国内隧道施工技术现状和贵广铁路隧道创新技术的现场实践,研究分析了制约隧道施工安全和施工效率的突出技术问题,取得了一系列研究成果:①基于精细爆破技术的微台阶开挖工艺可有效解决IV、V级围岩隧道开挖进度与工序安全距离之间的矛盾;②得益于通风技术和空气净化技术的进步,无轨运输方式可以适应于长大隧道的施工;③隧道仰拱快速施工设备和隧道沟槽移动模架的开发应用填补了这一领域的空白;④信息化施工是未来隧道施工技术发展的大趋势。     

Logit模型在南广高铁线客流分担预测中的应用

对分担率进行科学的预测是交通运输规划的基础性工作,是制定运输决策的重要依据。文章经过比较选取多项Logit模型为分担率预测模型,介绍了模型建立与求解的方法,并运用该模型对南广高铁沿线客流分担率进行预测分析。     

隧道长度对瞬变压力的影响

与阻塞比和车速不同,隧道长度对瞬变压力的影响呈现出明显的非单调性。这是在高速铁路隧道设计中必须考虑的问题。根据现场实测资料,研究分析了压力波的传播、反射和叠加规律,提出了单线隧道相应于压力变化不同情况的"最不利隧道长度"的计算图表及公式。     

广西沿海铁路建设双层集装箱通道必要性研究

广西沿海铁路作为大西南的重要出海通道,是防城、钦州、北海等重要沿海港口主要的后方集疏运干线。文章提出了广西沿海铁路开行双层集装箱列车的意义,预测了广西沿海铁路集装箱的运量,从经济与通过能力方面分析了广西沿海铁路开行双层集装箱列车的必要性。     

A new approach for improving the performance of freight train timetabling of a single-track railway system

A new approach for improving the performance of freight train timetabling for single-track railways is proposed. Using the idea of a fixed-block signaling system, we develop a matrix representation to express the occupation of inter- and intra-station tracks by trains illustrating the train blocking time diagram in its entirety. Train departure times, dwell times, and unnecessary stopping are adjusted to reduce average train travel time and single train travel time. Conflicts between successive stations and within stations are identified and solved. A fuzzy logic system is further used to adjust the range of train departure times and checks are made to determine whether dwell times and time intervals can be adjusted for passenger and freight trains at congested stations to minimize train waiting times. By combining manual scheduling expertise with the fuzzy inference method, timetable efficiency is significantly improved and becomes more flexible.     

既有线提速路基动应力分析

通过对既有线提速区段路基的调研和试验,得出结论,动应力与轴重、速度及线路平顺性有关。列车提速时,轴重增加和轨道不平顺对路基动应力影响最大。路基面动应力在横向呈马鞍分布,动应力沿深度方向衰减较快。采用当量折算和Boussinesq公式推算出的提速后路基动应力与实测值接近。在既有线提速改造中,重点应消除路基病害,提高基床特别是基床表层的强度和稳定性。     

中国铁路提速后技术进步对产出贡献的测算

选取我国铁路提速后1997~2007年间的相关数据,采用基于科布——道格拉斯生产函数的Solow余值法,将有限分布滞后模型和半参数回归模型引入计算模型,对数据进行拟合,计算得到铁路提速后技术进步、固定资本投入以及人力资本投入对产出的贡献率,并根据计算结果提出促进我国高速铁路建设的相关对策建议.     

涵洞基坑降水方案比选与参数分析

结合哈大铁路客运专线DK651+972涵洞施工的实例,论述了根据实际水文地质条件确定降水方案,对以往经验参数进行修改,以达到降水目的及确保工程顺利进行。     

制定战时铁路超限装备运输限界的研究

在阐述制定战时超限限界意义以及总结国外相关问题研究现状的基础上,进行了各种铁路限界标准的对比分析,对制定铁路超限限界的主要影响因素作了初步探讨,认为制定战时超限限界是可行的。     

Design and Application of Micropiles on Treatment for Landslide of High-speed Railway

Research purposes: The micro-pile has been used in foundation replacement, building reinforcement, retaining soil reinforcement, but the design and calculation theory of the micro-pile is seriously lagging behind. The design and calculation method and content of the micro-pile are not clear, and there are no relevant regulations. In this paper, the design and calculation method of landslide treatment by micro-pile is discussed, and its effect is monitored and analyzed. Research conclusions: (1) There are many advantages such as flexible construction and high construction efficiency. For landslide project with limited terrain, micro-pile has good governance effect and adaptability. (2) The monitoring data show that it is appropriate to adopt micro-pile treatment in the landslide project. After the micro-pile reinforcement treatment, the deformation of the landslide project has been quickly and effectively controlled, and the safety of the tunnel and roadbed engineering has been guaranteed. (3) The design content of the micro-pile should include the overall stability, the length of the pile, the pile spacing, and the reinforcement of the pile. (4) This paper can provide guidance for the design and construction of using micro-piles to control railway landslide. © 2021, Editorial Department of Journal of Railway Engineering Society. All right reserved.