CRTS Ⅱ型无砟轨道预加固植筋方案适应的升温幅度

Adaptive Temperature Rise Range for Pre-reinforcement Planting Bar Scheme of CRTS Ⅱ Ballastless Track

对CRTS Ⅱ型轨道板上拱病害进行预防加固的常见措施为在每块轨道板两端分别植入销钉。为研究植筋方案对升温幅度的适应性,根据销钉抗拔抗剪试验结果,建立CRTS Ⅱ型无砟轨道-销钉锚固体系有限元模型,计算分析轨道板无初拱变形、轨道板有初拱变形和考虑窄接缝缺损三种初始状态下,轨道板垂向位移及销钉拉拔力随轨道板升温幅度的变化规律,并分析植筋数量和销钉刚度的影响。结果表明:无宽窄接缝损伤时,既有植筋方案可保障轨道系统的稳定性;考虑窄接缝完全缺损的最不利情况时,既有植筋方案适应的升温幅度约为30.9℃。增加植筋数量对锚固性能的提高效果不明显;建议销钉抗拔刚度控制在55~100 kN/mm,且尽量偏小。

The common measure to prevent and reinforce the arching defect of CRTS Ⅱ track slab is to implant pins at both ends of each track slab. In order to study the adaptability of the planting bar scheme to the temperature rise range,based on the results of pin pull and shear resistance tests,a finite element model of CRTS Ⅱ ballastless track-pinanchorage system was established. The change laws of vertical displacement and pin pullout force of the track slab varying with the temperature rise range of the track slab under three initial states including no initial arch deformation of the track slab,initial arch deformation of the track slab and consideration of narrow joint defects were calculated and analyzed. The effects of the number of planting bar and pin stiffness were analyzed. The results show that the existing planting bar scheme can ensure the stability of the track system when there is no wide and narrow joint damage.Considering the most unfavorable situation of complete defects of narrow joints,the adaptive temperature rise range for the existing planting bar scheme is about 30.9 ℃. Increasing the number of planting bars has no obvious effect on the improvement of anchorage performance. It is recommended that the pull-out stiffness of the pin should be controlled at 55 ~ 100 kN/mm and be as small as possible.