In the dynamic analysis of simply supported railway bridges, the choice of vehicle models directly affects the quality of computed results. Simple moving load models usually overestimate the bridge response in comparison with models taking into account vehicle-bridge interaction effects. In order to compensate for this discrepancy, the Eurocode allows the increasing of structural damping for analyses performed with a moving load model. The specified additional damping is based on investigations carried out by the European Rail Research Institute in 1999 and may yield non-conservative results.

This paper describes an extensive parametric study inspired by the common Additional Damping Method, aiming to eliminate its identified shortcomings. The applied input parameters for the study are based on existing European simply supported bridge structures with a ballast layer. In order to match the vertical accelerations computed with the Detailed Interaction Model, the additional damping for the Moving Load Model is determined for four European high-speed trains. The results show that the additional damping as integrated in the Eurocode is non-conservative. A redesigned approach enables the definition of conservative additional damping functions depending on the natural bridge frequency, the bridge mass and the train type.

在简支铁路桥梁的动力分析中，车辆模型的选择直接影响计算结果的质量。与考虑车桥相互作用影响的模型相比，简单的移动载荷模型通常会高估桥的响应。为了弥补这种差异，Eurocode允许增加结构阻尼，以用于使用移动载荷模型进行的分析。指定的附加阻尼基于欧洲铁路研究所在1999年进行的调查，可能会得出非保守的结果。

本文介绍了一个受通用附加阻尼方法启发而进行的广泛参数研究，目的是消除其已发现的缺点。研究中应用的输入参数基于现有的具有压载层的欧洲简支桥梁结构。为了匹配用“详细交互模型”计算出的垂直加速度，为四辆欧洲高速列车确定了“运动载荷模型”的附加阻尼。结果表明，欧洲法规中集成的附加阻尼是非保守的。重新设计的方法可以根据固有的桥梁频率，桥梁质量和列车类型定义保守的附加阻尼功能。