桥上CRTSⅡ型板式无砟轨道底座张拉纵连模拟分析

Analysis on Base Tension and Vertical Connection Simulation of CRTS II Ballastless Slab Track

根据桥上CRTSⅡ型板式无砟轨道结构特点,建立桥上CRTSⅡ型板式无砟轨道底座施工全过程的有限元计算模型,分6个施工步骤分析底座从浇筑、张拉再到锁定整个过程中的受力及变形,研究表明:张拉前需确定底座锁定板温,以控制底座温度变化幅度;张拉时整个断面需均匀张拉,避免出现因应力集中而导致混凝土拉裂,当底座温差较大时,必须每隔24 h重复张拉1次,直到达到最终的张拉量;张拉完成后,BL2后浇带必须待混凝土浇筑段内应力均衡后方能浇筑。

According to the structure characteristics of CRTS Ⅱ slab track, a finite element calculation model aiming at the whole construction process of CRTS II slab track base is established. This paper analyzes the base load and distortion in whole processes from casting, tensioning to locking in six construction procedures. The study shows： in order to control the base temperature variation, the locking temperature of the base should be confirmed before tensioning; during tensioning process, the cross section should be tensioned uniformly to avoid concrete cracking caused by stress concentration; in case of greater temperature difference, tensioning shall be repeated every 24 hours until the final amount of tensioning is achieved; after tensioning, the BL2 post-poured band should be poured until the stress of the concrete pouring section becomes balanced.