钢波纹板套衬加固后隧道原有断面净空面积减小且突变，为准确掌握隧道加固后净空变化具体信息，提出采用三维激光扫描技术对钢波纹板套衬加固前后的隧道段分别进行扫描，建立包括外业扫描和内业处理的标准化工作流程。结果表明： 1）加固前隧道实际轮廓与设计存在一些偏差，不能直接利用设计资料加工钢波纹板； 2）三维激光点云数据处理结果不仅可以用于指导钢波纹板分段精细化加工，还可通过嵌套对比获取加固前后隧道净空变化信息，达到2次扫描即可实现工程情况全息掌握的目的； 3）钢波纹板套衬加固后隧道断面轮廓仍能满足隧道建筑限界要求，最大值位于隧道拱顶处，为20.9 cm。

Due to the reinforcement of prefabricated corrugated steel lining, the clearance area of the tunnel crosssection reduces and varies. In order to accurately clarify the specific information of tunnel clearance variation after reinforcement, 3D laser scanning technology is proposed to scan the tunnel sections before and after corrugated steel lining, meanwhile, a standardized workflow including field scanning and inner processing is established. The results indicate that: (1) There are some deviations between the profile of the actual tunnel and the design one, therefore the design data could not be used directly to process the corrugated steel. (2) The processed results of 3D laser point cloud cannot only be used to guide the segment refinement of corrugated steel, but also obtain the accurate variation of tunnel clearance before and after reinforcement by nested analysis. (3) The profile of the tunnel crosssection can still meet the limit requirement of tunnel construction after corrugated steel lining reinforcement with the maximum value of 20.3 cm at tunnel crown.