通过建立CRTSⅢ型板式无砟轨道结构1:1足尺试验模型,开展30 t轴重列车作用下轨道结构力学特性试验,获得800万次疲劳试验后轨道结构力学性能演化特征.研究结果表明:疲劳荷载作用下,CRTSⅢ型板式无砟轨道各层动力响应基本呈逐渐增加之势;800万次疲劳荷载作用后,扣件竖向动、静刚度分别增加24.77%和23.94%,竖向动静刚度比变化不明显;隔离层竖向动、静刚度分别增加152.27%和136.11%,动静刚度比减小6.4%;底座竖向加速度最大值增加67.4%;底座混凝土板中处拉、压应力最大值分别增加55.6%和26.3%.研究成果对于开展重载铁路CRTSⅢ型板式无砟轨道结构研究具有参考价值.%Heavy haul railway is the development direction of international railway freight transportation. In this paper, the 1:1 full scale test model of CRTS Ⅲ slab ballastless track structure was established, and experiment study on mechanical characteristics of the track structure under 30-ton axle load was carried out. The mechanical characteristics of the track structure were obtained after 8 million fatigue load tests. The results show that: The dynamic responses of different layers in CRTS Ⅲ slab ballastless track structure increase gradually under the action of fatigue load. After 8 million times of fatigue load tests, the vertical dynamic stiffness and static stiffness of rail fastener increases 24.77% and 23.94% respectively, and the change of vertical dynamic and static stiffness ratio is not obvious, meanwhile, the vertical dynamic and static stiffness of isolation layer increases 152.27% and 136.11% respectively, and the vertical dynamic and static stiffness ratio reduces 6.4%, moreover, the maximum of vertical acceleration of concrete base increases 67.4% and the maximum tensile stress and compressive stress in the middle of the concrete base increases 55.6% and 26.3% respectively. The research results would guide the research of CRTS Ⅲ slab ballastless track structure in heavy-haul railway.
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