温升荷载下宽窄接缝伤损对轨道板垂向稳定性的影响研究

Study on the Effect of Wide and Narrow Joints Damages on the Vertical Stability of Track Slab under the Load of Temperature Rising

宽窄接缝伤损是温升作用下CRTSⅡ型板式轨道(以下简称"Ⅱ型板")垂向失稳的主要原因之一,通过建立带宽窄接缝伤损的Ⅱ型板式轨道垂向稳定性分析模型,分析宽窄接缝弹性模量差异,窄接缝破损和宽、窄接缝交界面损伤等对温升荷载下轨道板垂向稳定性的影响。研究表明:温升荷载作用下,窄接缝弹性模量降低比宽窄接缝弹性模量整体降低对轨道板的垂向稳定性影响更为显著,施工时应保证宽窄接缝材料均匀,实现一致的弹性模量;窄接缝破损后,轨道板将出现带尖角的上拱波形,且窄接缝的损伤程度越高,轨道板上拱位移越大,结构越易发生破坏;宽、窄接缝交界面损伤对轨道板的垂向稳定性影响较小。

Wide and narrow joints damage is one of the main reasons for the vertical instability of CRTSIIslab track （hereinafter referred to as “Ⅱtrack slab”） subject to temperature rising. By establishing thevertical stability analysis model of Ⅱ track slab with narrow joint damage, this paper analyzes theinfluence of the elastic modulus difference, the narrow joint fracture and the wide and narrow jointinterface damage on the vertical stability of the slab under the temperature rise load. The results show thatthe elastic modulus reduction of the narrow joint imposes impact more significantly on the vertical stabilityof the track slab than the overall elastic modulus reduction of the wide and narrow joints; the elasticmodulus of the wide and narrow joints should remain consistent by using unified materials in theconstruction; once the narrow joint is broken, corrugated upper arch waveform appears on the track slab,and the higher the damage degree of the narrow joint, the greater the displacement of the arch, and it ismore likely to destroy the track slab; wide and narrow joints interface damage has less effect on thevertical stability of the track slab.