CRTSⅡ型板式无砟轨道板间接缝张拉力学分析

Tension Force Analysis of CRTS Ⅱ Slab-type Ballastless Track Caused by Widening Joint Between Track Slabs

CRTSⅡ型板式无砟轨道宽接缝伤损是一种较为普遍的病害,主要表现为冬季拉裂和夏季上拱。宽接缝作为轨道纵向连接的关键部位,出现伤损后会弱化轨道板之间的连接,可能会威胁到行车安全。本文建立CRTSⅡ型板式无砟轨道有限元计算模型,分析了张拉施工工艺对轨道板的影响,并结合现场轨道结构伤损情况,从宽接缝设计原理出发对其施工过程进行受力分析,得出张拉荷载对轨道板各部件的影响。研究结果表明:全长粘结和端部套管2种工况中,纵向钢筋张拉作用对窄接缝混凝土产生的预压应力并不大,且分布不均匀,在抵抗温度力方面,效果不明显。

The damage of wide joint in CRTS Ⅱ slab-type track is common,including tension crack in winter and arch in summer.As the key part of CRTS Ⅱ slab-type track,the wide joint will weaken the connection of track slabs and threaten the driving safety when it become serious.This article analysed the effect of track slabs by the pull construction technology on basis of CRTS Ⅱ slab-type track finite element model.Based on site track structure damage and the design principles of wide joint,the stress of construction process was analysed and the effect of tensile load on the components of slab-type track was deduced.The results show that in the working condition of full-length bonding and casing pipe at end,the effect of tensioning longitudinal reinforcement on narrow joint is not obvious and stress distribution is uneven.There is no significant effect on resistance to temperature force.