桥上纵连板式无砟轨道系统关键技术试验研究

Key technology of longitudinal- continuous- plate unballasted track system on bridge

作为桥上纵连板式无砟轨道系统的薄弱环节，砂浆层一旦发生损伤甚至脱空，将严重影响列车运行品质。围绕砂浆层界面工作性能这一关键课题，依托沪昆客专综合试验段，开展无砟轨道温度场长期观测、砂浆层界面黏结性能试验和桥上纵连板式无砟轨道动力测试，已取得阶段性成果。试验结果表明：桥上纵连板式无砟轨道竖向存在非线性温度梯度，轨道整体竖向温差可达-10～18．8℃，其竖向分布规律符合指数分布；砂浆层上表面与轨道板相接界面较为薄弱，其黏结力小于博格公司实验值，应予以关注；列车作用下，由上而下振动衰减明显，轨道板-底座板间相对位移大于底座板-桥面板间相对位移，再次证明了砂浆层在耗能和传力方面的重要作用。

Being a weak link of longitudinal - continuous - plate unballasted track system on bridge, it will seriously affect the quality of train operation once mortar layer is injured or void. Based on the comprehensive experimental section of the Shanghai - Kunming passenger line, the long - term observations of unballasted track tem- perature field, mortar layer interface bonding performance test and dynamic test of longitudinal - continuous - plate unballasted track on bridge were carried out in terms of work performance of mortar layer interface. The test shows that, there is a nonlinear vertical temperature gradient on longitudinal - continuous - plate unballasted track, and track overall vertical temperature can reach - 10 - 18.8 ~C, and the vertical temperature distribution is comply with the exponential distribution; the interface of mortar layer surface and track plate is relatively weak, and its cohesive force is less than the Berg company~ experimental value, which should be paid attention to; under the influence of the train load, top - down vibration attenuation is obvious, and the relative displace- ment of track plate - base plate is greater than that of base plate and bridge deck, which proves that the mortar layer plays an important role in energy consumption and force transmission.