高速车辆与桥上道岔动态相互作用规律初探

为揭示高速运营条件下车辆与桥上道岔的动态相互作用规律,建立考虑轮轨间动态接触关系的高速车辆-道岔-桥梁耦合振动模型,并编制相应计算程序CDAVTB。以时速350 km18号道岔布置于6×32 m连续梁上,轨下基础采用底座纵连式无砟轨道为例展开仿真分析,就铺设于我国客运专线桥梁上的引进技术与自主研发高速道岔的动力响应进行比较,并分析桥梁竖向刚度和岔桥相对位置对车岔桥系统动力响应的影响。结果表明:高速道岔铺设于桥上时,各项动力响应均有所增大,道岔结构参数对车岔桥系统动态相互作用的影响较大。随着桥梁竖向刚度的增大,系统各项动力响应呈减小趋势,32 m跨连续梁的ZK荷载挠跨比宜按不大于1/9 000进行设计。岔桥相对位置的变化将导致系统动力响应的较大差异,就32 m跨度连续梁而言,道岔辙叉部分布置于列车运行方向上距离桥墩1/8至1/4跨范围内时最优。

Preliminary Study on Dynamic Interaction of High Speed Vehicle and Turnout on Bridge

To reveal the dynamic interaction rule of high speed vehicles and turnouts on bridges,the dynamic coupling model of the high-speed vehicle,turnout & bridge system was established,which took into account the dynamic wheel-rail contact relationship,and the calculation software CDAVTB was programmed. Simulation analysis was made for the case when 18# turnouts with a design speed of 350 km-h were arranged on the 6×32 m continuous beam and continuous ballastless slab tracks weve laid as the foundation under rail.Dynamic responses of imported technology and independent research & development turnonts laid on bridges of dedicated passenger lines in China were compared;the influence of the vertical stiffness of bridges and turnout-bridge relative position on the dynamic responses of the vehicler-turnout-bridge system was analyzed.The research results show as follows:When high speed turnouts are laid on bridges,all dynamic responses increase and turnout structure parameters have great influence on dynamic interaction of the vehicle-turnout-bridge system;along with increasing of the vertical stiffness of the bridges,all dynamic responses show a decreasing tendency and the ratio of deflection to span under the ZK load of the continuous beam with 32 m span should be made less than 1/9 000 in design;changes of the turnout-bridge relative position may result in large differences in dynamic responses of the system;for a continuous beam with 32 m span,it is optimal to set the frog within a distance between 1/8 and 1/4 span away from the pier in the moving direction of the vehicle.