Experimental evaluation of the efficiency of trenches for the mitigation of train-induced vibrations

In this work, the efficiency of absorbing barriers for the mitigation of ground vibrations induced by railway traffic has been evaluated by means of two different experimental campaigns conducted in situ, along the newly-built, high-speed railway line that connects the Italian cities of Milan and Bologna. In the first stage of testing, a series of ideal barriers created from unsupported empty trenches were tested to assess the effects of barrier depth on their efficiency in reducing vertical ground accelerations. The second stage of testing was performed to investigate the efficiency of a full-scale prototype barrier, made of a 2-meter-deep trench supported by two precast reinforced concrete plates connected by steel bars, during transit of an ETR 500 train at a speed of 120 km/h.     

Dynamics of the railway track and the underlying soil: the boundary-element solution, theoretical results and their experimental verification

A combined finite-element boundary-element method is presented in detail to calculate the dynamic interaction of the railway track and the underlying soil. A number of results are shown for ballasted and slab track, demonstrating the influence of the stiffness of the soil and the rail pads on the vertical compliance of the track. The compliance of the track is combined with a simple model of the vehicle giving the transfer function of vehicle-track interaction. An experimental verification of the theoretical results is achieved by harmonic and impulse excitation with and without static (train-) load and by combined measurements of train-track-soil interaction. A clear vehicle-track resonance is found for the slab track with elastic rail pads and for higher frequencies at highspeed traffic, the dynamic axle loads due to sleeper passage are reduced.     

工程断裂构造及其公路隧道工程效应

为了解决活断层工程效应,通过对断裂构造工程效应和工程处理全过程的综合分析,理论解析了断裂构造工程效应研究的前沿课题,并结合隧道工程实践,剖析了公路隧道活断层效应应用基础研究的方案,提出了断层错动自然影响带划分、断层错动围岩稳定性空间定量评价和活断层隧道工程对策研究等需要解决的关键问题。     

确定软横跨横承力索最低点位置的计算方法

介绍了确定接触网软横跨横承力索最低点的一种计算方法,并以北京—郑州段电气化改造中保定南站的软横跨横承力索为例进行了计算,证明该计算方法可简化软横跨多的车站和区间的横承力索计算。     

基于GPRS的振弦式传感器测频系统

针对传统桥粱振动频率测量系统存在数据采集实时性差的缺点，提出基于GPRS无线网络的数据采集方法。以Atmega128单片机为现场数据采集端的MCU，并以MC35为GPRS Modem来实现与互联网接入，将GPRS无线技术引入桥梁安全检测测频系统，非常适用于要求实时性的、大数据量传送的远程数据监控系统应用场合。     

银铜合金接触线新工艺的研究

根据连续挤压工艺原理，提出“上引连铸-连续挤压-(轧制)-拉拔”银铜合金接触线制造新工艺。用扫描电子显微镜对新工艺生产的接触线进行显微组织观察分析，得出其横断面的平均晶粒度为8．62μm，在室温下的导电率为102．2％IACS、延伸率为7．78％、拉断力为47．42kN。用新工艺生产的接触线晶粒细小、均匀，其导电率、延伸率、拉断力等性能都明显提高。     

超导复合多芯线内饱和区界线

本文给出了当超导复合多芯线位于高斜率迅变横向磁场中，多芯线内饱和区界线的理论计算式。此结果与已有的理论计算，也就是应用超导单芯线理论于多芯线场合的计算结果有明显的差别，其原因在于本理论考虑了饱和区内屏蔽电流的回路径路的存在。     

钢丝绳失效机理分析及改进举措

微动疲劳与腐蚀疲劳是造成钢丝绳失效的主要原因。选用纯净度高的帘线钢盘条为原料制造钢丝绳,并对制绳钢丝进行表面处理,提高钢丝的防腐蚀、耐磨损性能,同时通过改进设备和工艺提高捻制质量,可大幅度地提高钢丝绳的质量和使用寿命。光面钢丝绳或将被淘汰。     

基于LTE系统的轨道交通辅助定位方法

为保证城市轨道交通运营安全,针对车载控制器(VOBC)出现故障时,调度人员无法获悉列车位置的情况,利用列车接入单元(TAU)上传长期演进系统(LTE)的无线性能指标进行辅助定位。该系统平时进行车辆实际位置和无线性能指标的大数据拟合,在特殊情况时利用拟合曲线和无线性能指标进行辅助定位,为列车安全运行提供可靠的保障。     

钢铰线拉索式落梁防止装置设计

钢铰线拉索式落梁防止装置具有结构紧凑、静载性能好、疲劳寿命高和锚固可靠等特点,可为桥梁结构在强烈地震作用下的安全提供可靠的保障,文章对该钢铰线拉索式落梁防止装置的构成和应用设计进行介绍。