A method for testing railway wheel sets on a full-scale roller rig

Full-scale roller rigs for tests on a single axle enable the investigation of several dynamics and durability problems related with the design and operation of the railway rolling stock. In order to exploit the best potential of this test equipment, appropriate test procedures need to be defined, particularly in terms of actuators’ references, to make sure that meaningful wheel –rail contact conditions can be reproduced. The aim of this paper is to propose a new methodology to define the forces to be generated by the actuators in the rig in order to best reproduce the behaviour of a wheel set and especially the wheel –rail contact forces in a running condition of interest as obtained either from multi-body system (MBS) simulation or from on-track measurements. The method is supported by the use of a mathematical model of the roller rig and uses an iterative correction scheme, comparing the time histories of the contact force components from the roller rig test as predicted by the mathematical model to a set of target contact force time histories. Two methods are introduced, the first one considering a standard arrangement of the roller rig, the second one assuming that a differential gear is introduced in the rig, allowing different rolling speeds of the two rollers. Results are presented showing that the deviation of the roller rig test results from the considered targets can be kept within low tolerances (1% approximately) as far as the vertical and lateral contact forces on both wheels are concerned. For the longitudinal forces, larger deviations are obtained except in the case where a differential gear is introduced.     

钻机车动力系统的选择

通过对钻探负载特性的理论分析,结合钻探工作的特点和环保对汽车排放的要求,按照地质钻机对动力系统驱动特性的基本要求,对DPP100系列钻机车动力系统选择的研究和方法进行了论述。     

双轮铣槽机与管棚钻机配合施工在地铁围护结构工程中的应用

目前在国内城市的地下连续墙施工中由于地质情况复杂及交叉施工干扰,采用单一设备施工局限性较大,为了解决双轮铣槽机在复杂地层及硬岩条件下施工效率较低问题,采用BC36液压双轮铣槽机与管棚钻机配合施工,有效地提高了设备施工成槽效率,对城市结构围护工程具有较好的参考价值。     

武汉鲁巷广场综合交通规划与设计研究

武汉鲁巷广场位于中国光谷的中心地带,是六条道路的交汇点,中央形成交通及景观环岛。该文从分析周边的路网特征、环岛交通现状和土地利用对交通的影响出发;在借鉴国内同类型环岛规划的基础上,综合城市的总体发展战略、土地利用规划、综合交通规划等各方面,探讨了环岛广场在规划设计过程中所涉及的交通衔接、土地利用、规划调整和工程设计等一系列问题及其解决方案。     

旋挖钻机在泰州大桥施工中的应用

文章简述了旋挖钻机的施工工艺,并结合泰州大桥施工实例分析了旋挖钻机的特点,希冀为旋挖钻机的广泛应用提供参考。     

兰渝线化马隧道涌水处理

化马隧道涌水为高压宽张岩溶裂隙水,具有水量大、压力高、涌水连续、贯通性好、补给水头稳定等特点。通过详细的地质勘探、地质超前预报、超前钻孔探测水情,掌握了涌水的特点和性质,提出了采用迂回导坑绕避结合泄水洞排水的处理方案,顺利的通过了隧道涌水段。     

钻孔机旋挖取土成孔法施工工艺研究

旋挖钻机是一种适合建筑基础工程中成孔作业的施工机械,目前已被推广应用于各种钻孔灌注桩工程。因此,对钻孔机旋挖取土成孔法施工工艺进行探讨具有一定的意义。     

桥梁钻孔桩坍孔的预控措施

在目前桥梁建设项目的施工过程中,桥梁钻孔技术已经被广泛的应用,但坍孔问题却给该技术效能的有效发挥带来了不利影响。     

基于深海钻井平台动态定位系统的研究

随着海洋石油工业由浅海向深海的转移,动态定位系统在海洋工程船舶中的应用也越来越广泛,动态定位的级别也越来越高。本文就世界首艘圆筒形钻井平台某深海钻井平台的动态定位系统进行介绍,动态定位在海洋工程船舶上的应用将得到快速地推广,对航海科技的进步和航海安全水平的提高,必将产生深远的影响。