针对高速铁路的桥涵与临近路基由于存在材料和沉降的差异形成的刚度和几何不平顺,对路涵过渡段的动态响应和影响范围进行研究。本文建立“车辆-轨道-过渡段”垂向耦合动力模型,研究过渡段路基的动态响应特征,并与京沪高速铁路廊坊段路涵过渡段现场实测值进行对比。结果表明,当运行速度小于300 km/h 时,过渡段基床动应力、加速度、垂向位移等随速度增加而增大；在300 km/h 时动应力、加速度出现最大值,动位移随行车速度呈线性增大；从动应力、加速度的影响范围看,运行速度在300 km/h 以下时路涵过渡段影响范围为20~25 m,300 km/h 及以上时,过渡段长度达到30~35 m。当设计速度超过300 km/h 时,应适当加长路涵过渡段长度。%According to the situation that there are stiffness and geometrical irregularities in the transition between subgrade and culvert /bridge due to the differences in material and deformation,researches on transition be-tween culvert and subgrade are carried out.In this paper,the vertical coupling dynamic model of vehicle-track-transitional section was built to sudy the characteristics of dynamic responses in transitional section between culvert and subgrade.Then,the results of the model were comparied with field tests of conducted in the Lang-fang segment of the Beijing-Shanghai High-speed Railway Line.The results show as follows:When a train runs at a speed lower than 300 km/h,the dynamic stress,acceleration and vertical displacement in transition increase with raizing of the train speed;when at the speed of 300 km/h,the dynamic stress and acceleration reach the maximum and the dynamic displacement increases linearly with raizing of the train speed;referting to the influence scope of the dynamic stress and acceleration in the transitional section,it covers 20 ~ 25 m at the speeds of 300 km/h and less and extends to 30 ~ 35 m at the speeds of higher than 300 km/h;when the de-signed speed is higher than 300 km/h,the length of transitional section should be appropriately extended.
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