摘 要：针对桥上无缝道岔，运用有限单元法，建立了钢轨－岔枕－桥梁弹簧-阻尼空间振动模型。运用弹性系统动力学总势能不变值原理及形成矩阵的“对号入座”法则建立了列车－道岔－桥梁空间振动方程组。以温福客运专线田螺大桥为例，拟定桥上铺设了由两组38号道岔组成的单渡线。计算了“中华之星”电动车组，按一动四拖的编组方式，以140km/h的速度侧向通过时，列车－道岔－桥梁空间振动的动力响应。分析了侧向过岔时，列车运行速度、轨下横向刚度、枕下横向均布刚度、桥墩高度对列车－道岔－桥梁系统振动的影响。结果表明：桥梁导致钢轨和岔枕的位移增幅较大，车体振动加速度有所增加，道岔振动加速度、轮轨力变化很小；系统横向振动响应随列车速度增大、轨下横向刚度减小、枕下横向均布刚度减小、桥墩高度增大而增加。

Abstract: Aiming at seamless turnout on bridge, the rail-turnout tie-bridge spring-damping vibration model was built by using finite element method. The train-turnout-bridge spatial vibration equation sets were formulated by using the principle of total potential energy with stationary value in elastic system dynamics and the “set-in-right-position” rule for formulating matrixes. Taking Tian-luo major bridge in Wenzhou-Fuzhou railway line for passenger as an example, it was assured that there was a crossover combined with two No.38 turnouts on the bridge. The train-turnout-bridge spatial vibration dynamic responses were analyzed when “China Star” high speed train with 1 locomotive and 4 passenger cars at the speed of 140km/h through turnout branch. The influences of train velocity, the lateral stiffness under rail, the lateral uniform stiffness under tie and the height of pier to the train-turnout-bridge system vibration were analyzed. The results show that bridge leads the displacement of rail and turnout tie increase very much, the dynamic responses of train increase a little, and it has little effect to the acceleration of turnout and wheel/rail force. The system responses increase with the increasing of train velocity, the decreasing of lateral stiffness under rail, the decreasing of lateral uniform stiffness under tie, and the increasing of pier height.