基于有限元法,考虑钢轨、无砟道床、滑动层、桥梁等结构的相互作用关系,建立桥上纵连板式无砟轨道无缝线路纵-横-垂向空间耦合模型,进行滑动层摩擦系数、扣件纵向阻力、无砟道床伸缩刚度等对桥上纵连板式无砟轨道无缝线路的受力和变形影响规律的研究.结果表明:滑动层减弱了桥梁、轨道间的相互作用,当滑动层摩擦系数为0.1～0.5时,无缝线路伸缩力仅为22.821～55.361 kN,远小于一般桥上无缝线路结构；滑动层摩擦系数越小越有利于轨道和桥梁结构的安全使用；底座板/轨道板的伸缩刚度减小会明显增大部分轨道和桥梁的受力,伸缩刚度折减至10％时,伸缩力会增大近6倍,因此应该注意控制底座板和轨道板的开裂现象；扣件的纵向阻力变化对轨道和桥梁结构的受力和变形几乎没有影响,但为了防止钢轨爬行或断缝值超限,扣件阻力不宜太小.%Based on finite element method, considering the interaction between the rail, ballastless track bed, sliding layer and bridge, the longitudinal-transverse-vertical spatial coupled model of longitudinally connected ballastless track continuously welded rail on bridge is established. The influence law of the sliding layer friction factor, fastener longitudinal resistance and expansion stiffness of ballastless track bed on the force and deformation of the longitudinally connected ballastless track continuously welded rail on bridge is analyzed. Results show that the sliding layer weakens the interaction between bridge and track, and when the friction factor of the sliding layer ranges from 0.1 to 0. 5, the contractility of continuously welded rail is only from 22. 821 to 55. 361 kN, which is much smaller than that of the general continuously welded rail on bridge; the smaller the sliding layer friction factor on bridge, the safer the track and bridge structure. The force and deformation of part of the track and bridge would be increased obviously by reducing the expansion stiffness of bed plate or track slab. When the bed plate/track slab expansion stiffness is reduced to 10%, the contractility nearly increases six times. So the crack of concrete of bed plate and track slab should be strongly controlled. The influence of the fastener longitudinal resistance on the force and deformation of the track and bridge is almost negligible, but the fastener resistance should not be too small to avoid rail creeping or the rail broken gap overrun.
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