双块式无砟轨道连续式道床板后浇带施工工艺研究

Construction Technology of Post Casting Belt for Continuous Roadbed Slab of Double Block Ballastless Track

针对路基段双块式无砟轨道结构连续式道床板易开裂的难题,从结构形式、温度应力、混凝土收缩和施工方法 4个方面对双块式无砟轨道结构的开裂原因进行了分析。借鉴长大连续梁设置后浇带的设计理念,提出了道床板设置后浇带的分段浇筑施工工艺。从先浇段分段长度、后浇带预留长度、新老混凝土结合面加强及后浇带施工控制4个方面确定了后浇带结构设计参数及施工保证措施,并进行了现场应用。结果表明,该施工工艺对抑制道床板收缩裂缝效果显著,具有推广价值。

According to the crack problem of continuous roadbed slab of double block ballastless track structure in subgrade section,the crack causes of double block ballastless track structure were analyzed from structural style,temperature stress,concrete shrinkage and construction method.Using design concept of post casting belt setting in long and large continuous beam,the subsection casting construction technology of the post casting belt setting for the roadbed slab was put forward.The design parameters of the post casting belt structure and the construction guarantee measures were determined from such aspects as fractional length of pre-casting section,reserved length of post casting belt,strengthening joint surface between new and old concrete and construction control of post casting belt,and the f ield application was also carried out.The results show that the construction technology has a remarkable effect on restraining the shrinkage crack of the roadbed slab and has the popularization value.