为满足高速列车安全、舒适性的需要，保证线路的高平顺性，无碴轨道的铺设与运营对路基、桥涵、隧道等线下结构的工后沉降要求非常严格, 追求“零沉降”理念。以武广铁路客运专线为基础，系统地介绍了线下结构物沉降变形观测关键技术，数据管理与分析预测系统，提出了工后沉降的预测方法及评估条件与标准，合理确定无碴轨道开始铺设时间，以保证客运专线无碴轨道结构铺设的质量。并提出了一些体会和建议，为正在建设的无砟轨道客运专线提供借鉴。

The criterion for residual deformation of Substructure of unballasted track on railway passenger dedicated line is extremely strict in order to satisfy the safety and comfort requirements of the high-speed train. Based on new Wuhan(Guangzhou railway passenger dedicated line engineering practice,this paper introuduces the key technologies for the deformation monitoring, data management and analysis system, the prediction method and assessment criterion are put forward to determine the reasonable time of unballasted track laying to guarantee the quality of unballasted track. Some advice provide reference for the ongoing unballasted track on railway passenger dedicated line construction.