高速铁路桥梁地段综合接地系统工程设计的探讨

结合新建安庆至九江铁路实绩,针对高速铁路桥梁地段综合接地系统在工程设计过程中的设置原则、设计方案,及施工配合过程中遇到的问题,探讨解决方案。     

典型交叉区域GSM-R无线覆盖方案设计

对交叉区域按两线交叉相对位置关系、线路的列控等级、基站设置位置与交叉点位置关系、有无联络线等因素进行了详细分类,并针对每种类型给出了具体的无线覆盖方案建议;然后选取了郑徐客专与京九线交越区域和商合杭铁路引入芜湖站二个典型案例,将交叉区域无线覆盖方案设计建议进行了示范应用;最后总结了交越区域GSM-R系统的设计原则,其他铁路交叉区域的GSM-R系统方案设计可直接参考。     

A Stated preference freight mode choice model

Transport policy aims to assist the transport system to work more efficiently and effectively. An understanding of the reasons why people choose to move freight in a certain manner is critical to the development of appropriate policies. This article outlines a data collection approach and the development of a disaggregate mode choice model applicable to the analysis of freight shipper decision making. It focuses on the choice between rail and road in Java, Indonesia. The model indicates that safety, reliability and responsiveness are major attributes influencing rail/road freight mode choice. Transport policies aimed at improving these dimensions should increase the attractiveness of rail transport.     

一种新型城市快速路网交通诱导系统的研发和应用

介绍了一种新型的基于可变信息标志(VMS)的网络级城市快速路交通诱导系统的设计方法。该系统是一个由“重要决策点图形式VMS”、“次要节点图文混合式VMS”、以及“地面一般道路VMS”三类VMS组成的VMS系统。文章在归纳VMS系统设计流程基础上,重点介绍了VMS的路网布局和功能设计、显示格式和显示技术的确定、VMS设立位置(前置距离)的确定、图形式VMS的面板设计和交通信息发布策略等关键技术,最后给出系统的应用实例,说明该新型交通诱导系统的应用效果。可供交通管理部门规划、设计城市快速路网交通诱导系统参考。     

扣件式钢管脚手架设计与施工要点探析

文章利用Midas Civil软件建立计算模型,对扣件式钢管脚手架的立杆自由长度、纵横立面剪刀撑、水平剪刀撑在支架体系中的作用进行分析,同时分析了地基不均匀沉降对支架体系的影响,提出了扣件式钢管脚手架的设计与施工要点。     

钢轨超声波探伤仪灵敏度20%林状回波调节法

针对现场参照物调节法和对比试块调节法存在不能不断合理调节各通道灵敏度,以及探伤仪对小尺寸钢轨缺陷检出能力低的问题,分析、研究钢轨超声波探伤仪探伤质量影响因素,提出采用20%林状回波调节法调整钢轨超声波探伤仪灵敏度。介绍20%林状回波调节法调整钢轨超声波探伤仪灵敏度基本原理、操作方法和注意事项。经现场验证,该方法能够提升钢轨缺陷检出能力,符合TB/T 2340—2012《钢轨超声波探伤仪》中关于钢轨缺陷检出能力的规定,提高钢轨超声波探伤质量。     

A procedure for predicting the permanent rotation of monopiles in sand supporting offshore wind turbines

Foundations for Offshore Wind Turbines (OWTs) are designed following the limit state philosophy. One of the considered states is the Serviceability Limit State (SLS), which verifies that the permanent rotation of the foundation generated from accumulated strains in the soil is below a project specific criterion. Despite design codes requiring an estimation of the permanent rotation, there is not clear guidance on how to implement this. This paper describes a methodology to estimate the monopile permanent rotation for SLS and discusses its advantages and limitations. The methodology combines an accumulation method with results from 3D Finite Element Analyses (FEA) and a soil model that accounts for strain accumulation as a function of the number of cycles, relative density and load characteristics. The performance of the proposed methodology is compared against experimental centrifuge tests and results from advanced 3D FEA, indicating that it can predict the permanent rotation with satisfactory accuracy, and with a considerable reduction in computational effort. This is important for the design of OWTs, where different load histories might be required to be checked – often under tight time constraints – to find which load history leads to the largest permanent rotation, and therefore is more critical to SLS design.     

山区铁路自建砂石料加工厂设计探讨

山区铁路在施工过程中会产生大量的土石弃方,既占用土地又影响环境。针对自建砂石料厂选址、场地布置、材料标准、工艺设备选型、加工工艺等进行探讨,并辅以案例从经济效益、环境保护等方面进行分析,结论表明,在山区铁路建设中自建砂石料加工厂利大于弊,既满足了建设需求,又最大限度地保护了生态环境。     

SCFs in tubular X-joints retrofitted with FRP under out-of-plane bending moment

This paper presents a parametric study on the stress concentration factors (SCFs) on the chord member in tubular X-connections reinforced with fiber reinforced polymer (FRP) under out-of-plane bending moment. For this aim, a FE model was generated and validated using several available experimental tests. After that, a set of 276 FE models was created to evaluate the effect of the FRP (layer number, orientation, and material) and joint geometry (γ, τ, and β) on the SCFs. In these FE models, the contact between the FRP sheets and the steel members (chord, weld, and braces) was modeled. Results indicated that the rise of the FRP laminate number causes a notable drop of the SCFs, especially in the connections with big γ. Moreover, the increment of the elastic modulus of FRP along the fibers causes a notable decrease of the SCF. Results showed that, for certain geometrical parameters set, the SCF in an X-connection retrofitted with carbon fiber reinforced polymer (CFRP) can be down to 23% of the SCF in the associated un-retrofitted connection. Despite the notable efficacy of the FRP sheets on the drop of the SCFs in the X-connections, there is not any study or equation on the X-connections with FRP. Therefore, an equation was proposed for quantifying the SCFs in the X-connections with FRP.     

基于BIM技术的铁路客车车辆段设计研究

近年来,随着BIM技术在铁路行业的逐步普及,铁路工程的信息化程度要求也越来越高。在车辆段建设过程中,传统的二维图纸设计无法实现工程项目设计、施工、运用的信息共享,也不能满足设计阶段多专业的协调需求。如何利用BIM技术实现设计信息的无损传递,提高车辆段设计水平和信息化水平是业内亟待解决的问题。为解决上述问题,依托西安站改客车段项目,对车辆段BIM设计软件解决方案和实施流程进行探索,验证车辆段BIM设计流程,完成车辆段BIM模型的建立并对其进行碰撞检查、排烟分析、日照模拟、工筹策划等应用拓展,结合BIM实践经验,优化提高铁路车辆段的设计手段。