Weighing in motion and characterization of the railroad traffic with using the B-WIM technique

AbstractThe knowledge on the active moving load of a bridge is crucial for the achievement of the information on the behavior of the structure, and thus foresee maintenance, repairs and better definition of the logistics of its active vehicles. This paper presents the development of the algorithms for the application of the Bridge-Weigh In Motion (B-WIM) method created by Moses for the weighing of trains during motion and also for the characterization of the rail traffic, allowing the obtainment of information like passage's train velocity and number and spacing of axles, eliminating the dynamic effect. There were implemented algorithms for the determination of the data referring to the geometry of the train and its loads, which were evaluated using a theoretical example, in which it was simulated the passage of the train over a bridge and the loads of its axles were determined with one hundred percent of precision. In addition, it was made a numerical example in finite elements of a reinforced concrete viaduct from the Carajás' Railroad, in which the developed system reached great results on the characterization and weighing of the locomotive when the constitutive equation of the Brazilian Standards was substituted by the one proposed by Collins and Mitchell.

摘要
获取桥梁动态移动荷载的相关知识，对于掌握结构行为信息、进而预判养护维修工作，以及更合理地规划其运营车辆的调度物流至关重要。本文阐述了由Moses提出的桥梁动态称重（Bridge-Weigh In Motion，B-WIM）方法的应用算法开发工作，该方法既可用于列车运动状态下的称重，也可用于轨道交通特征分析，能够在消除动态效应的前提下，获取列车通行速度、轴数及轴间距等信息。本研究开发并实现了用于获取列车几何参数及荷载相关数据的算法，并通过理论算例对算法进行验证：在该算例中模拟了列车通过桥梁的过程，最终以百分之百的精度确定了各轴的荷载值。此外，本研究针对卡拉加斯铁路（Carajás' Railroad）的一座钢筋混凝土高架桥搭建了有限元（finite elements）数值算例；当采用Collins与Mitchell提出的本构方程（constitutive equation）替代巴西标准（Brazilian Standards）的本构方程时，所开发的系统在机车特征分析与称重工作中取得了优异结果。