单天窗期横向拨轨更换无砟轨道伤损轨道板关键技术创新与实践

针对切轨更换法和抬高钢轨换板法更换轨道板的弊端,提出在不切断钢轨情况下单天窗期内采用横向拨轨换板法更换轨道板的全套技术,并进行理论分析、试验验证及工程实践。结果表明:横向拨轨换板法可实现在不切断钢轨的前提下更换伤损轨道板,避免无缝长钢轨的切割及后续焊缝处易断轨的潜在风险;根据换板区钢轨实际锁定轨温、实测钢轨温度及相关有限元分析与迭代计算等确定拨轨前换板区前后须松开扣件的最小长度,辅以可靠的轨道状态监控,可确保横向拨轨时长钢轨锁定轨温不变、钢轨应变在弹性范围内,无塑性变形或硬弯损伤;轨道板更换施工未对轨道结构动态响应产生不利影响,新轨道板与相邻原轨道板的振动加速度相差不大,满足动车组安全、舒适的运输要求。

Innovation and Practice of Key Technology to Replace Damaged Concrete Track Slab of Ballastless Track Adopting Transversely Rail-moving Method in a Single Maintenance Window Period

In view of the disadvantages of rail switching replacement method and rail raising and slab replacing method,this paper put forward a complete set of technology to replace the rail slab by using the transversal rail transferring and slab replacing method in the single maintenance window period without cutting the rail,and carried out theoretical analysis,experimental verification and engineering practice.The results show that the transversal rail transferring and slab replacing method can replace the damaged track slab without cutting the rail at present,so as to avoid the potential risk of cutting the seamless long rail and easily breaking the rail at the subsequent weld,according to the actual locked rail temperature,the measured rail temperature and the related finite element analysis and iterative calculation in the slab changing area,the minimum length of the fastener which must be loosened before and after in the slab changing area before the rail transferring is determined,which could be supplemented by reliable rail state monitoring to ensure that the constant locked rail temperature of the long rail during the lateral rail transferring,the rail strain within the elastic range,and no plastic deformation or hard bending damage.The replacement construction of track slab has no adverse effect on the dynamic response of track structure.The vibration acceleration of the new track slab is similar to that of the adjacent original track slab,which could meet the requirements of safe and comfortable transportation of EMU.