双块式无砟轨道轨枕脱空处水的特性研究

Research on Characteristics of Water beneath Voided Sleeper in Bi-block Ballastless Track System

通过对我国无砟轨道服役情况的调研发现,在降雨量丰富的地区或排水不良的地段,双块式无砟轨道破损的速率较干燥地区要快得多。在高速、高频列车荷载作用下,枕下自由水变成具有一定压强、流速的动水,动水会加速裂纹的扩展,冲刷轨枕与道床板交界面的混凝土,从而影响轨道结构的耐久性,行车平稳性和安全性。通过计算流体力学软件ANSYS CFX,建立了轨枕-水-道床板流固耦合动力学模型,计算了轨枕脱空下水体的压强和流速的数值大小,为深化动水研究提供参考。

Through investigation and study on the service condition of the bi-block ballastless track in China, it can be seen that the breakage rate of bi-block ballastless track in rich rainfall areas or in poor drainage areas runs much faster than that in dry areas. Under the action of train loads with high speed and high frequency, the free water beneath the voided sleeper would become dynamic water with certain pressure and flow rate. In turn, the dynamic water would accelerate the crack spreading and scour the concrete of the bonding interfaces between sleeper and track slab, affecting the durability, safety, and riding quality of track structure. In this paper, ANSYS CFX, a software of computational fluid mechanics, was utilized to establish a fluid-structure coupling dynamics model among the sleeper, water and the track slab; and then the values of water pressure and flow velocity were calculated when sleeper being voided. This research can serve as references for in-depth study of dynamic water.