无砟轨道板端上拱变形影响规律研究

Research on effect law of arch deformation of ballastless track slab

为探明CRTSⅡ型板式无砟轨道层间黏结状态与板间接缝状态对轨道板端上拱变形的影响规律,基于有限元方法和内聚力理论建立了可同时考虑层间和板间黏结状态的上拱非线性分析模型,对不同的层间黏结状态与不同的板间接缝状态下轨道板端的上拱变形情况进行了研究.研究结果表明:层间界面强度和断裂能的增加有利于抑制轨道板上拱变形,界面刚度的增加会导致层间损伤的加速产生;层间初始离缝存在于轨道板端部时会加速轨道板上拱变形,但在极端高温荷载下初始离缝范围并不影响轨道板的最终上拱幅度;板中离缝相比于板边离缝对轨道板的上拱变形更为不利;在窄接缝损伤超过60%后,轨道板上拱位移增加速度有明显提升;窄接缝损伤高度对轨道板上拱的影响明显大于损伤长度对其的影响;轨道板端与宽窄接缝的黏结界面离缝后,轨道板上拱位移有所增大.

To verify the effects of CRTSⅡtrack interlaminar bonding state and joint state on arch deformation at slab end,a non-linear arch analysis model considering both interlaminar and joint bonding state was established based on finite element method and cohesion theory,and the arch deformation of track slab under different interlaminar bonding state and joint state was studied.The results show that the increase in interlayer interface strength and fracture energy is beneficial to suppress the arch deformation of the track panel,however increased interface stiffness can lead to accelerated damage between layers.The initial interlayer gaps at the end of slab can accelerate the slab arch,but not affect the ultimate deformation amplitude under extreme high temperature.The gaps in the middle of slab contribute more to arch deformation compared with that at the edge of slab.When narrow joint damage percentage exceeds 60%,the arch displacement increases faster obviously.The effect of narrow joint damage height on slab arch is greater than that of damage length.The arch displacement increases after the slab is separated from the joint.