为研究重载列车提载对既有铁路简支 T 梁结构动力响应的影响，以常用跨度16、20、24 和 32m 预应力混凝土简支 T 梁为例，建立重载列车 － 轨道 － 桥梁三维耦合精细化有限元模型; 选取朔黄铁路线上一座典型预应力混凝土简支 T 梁桥进行了现场试验，验证了有限元模型的准确性。计算重载列车作用下车桥系统的动力响应，探讨重载列车提载对桥梁结构动力响应的影响规律，并对既有铁路典型桥梁进行列车提载适应性分析。结果表明: 采用同种货物列车车型时，各跨度桥梁的位移响应随列车轴重的提高呈近似线性增加关系，加速度响应随列车轴重的提高有所增大; 采用不同货物列车车型时，各跨度桥梁的动力响应随列车轴重的提高波动较大，其变化与轴重提高的相关性不明显; 列车车体长度和车辆定距对跨度较大的桥梁影响较大，当桥梁跨度很小 (小于 8m) 时，重载列车对桥梁所产生的动力响应仅与轴距有关。当列车轴重提至 30 t 及以上时，既有铁路典型桥梁横向动力响应偏大，应进行横向加固。

Taking the prestressed concrete simple T-shape beam bridge with common span of 16，20，24 and 32m as an example，the 3-D finite element model of the coupled heavy haul train-track-bridge system was constructed to study the impact of increasing load of heavy haul train on the structural response of prestressed concrete simple T-shape beam bridges in existing railways． The accuracy of model was verified by a case study of a typical pre-stressed concrete simple T-shape beam bridge in Shuo-Huang railway． The dynamic response of the train-bridge system under heavy haul train was calculated，the influencing rule of increasing load of heavy haul train on the dynamic responses of railway bridge structure was discussed． And the adaptability of increasing load of heavy haul train in typical bridges of the existing railways was also analyzed． The results show that when using the same kinds of freight trains，the displacement responses of the each span bridge increase linearly as the axle load of freight train increase，and the acceleration responses increases with the increase in the axle load of freight train． When using different kinds of freight trains，the dynamic responses of each span bridge fluctuated with the increase of the axle load，and the relationship between its change and the increase of axle load is not obvious． The length of train body and vehicle distance have a big influence on long-span bridges． When the span is small (less than 8m)，the dy-namic response of the heavy haul train to the bridge is only concerned with the wheelbase． When the train axle is lifted to 30t and above，the lateral dynamic response of typical railway bridges is rather large，so lateral reinforce-ment should be carried out．