Research on the Characteristics of Voids Behind Tunnel Linings Based on Ground Penetrating Radar Non-Destructive Testing Technology
To uncover the distribution patterns of delamination behind the lining and provide guidance for professionals in the field,this study combines engineering surveys with on-site inspections to investigate the characteristics of delamination in tunnel linings.The results show that delamination behind the lining is predominantly con-centrated in the crown and intrados,accounting for as much as 93%of the recorded data,the longitudinal length of delamination behind the lining is heavily influenced by the length of the secondary lining operation trolley,with 92.4%of detected delamination defects having a longitudinal length of≤9 m,the height of delam-ination behind the lining is closely associated with the thickness of the secondary lining,with delamination de-fects detected in 99.1%of cases having a height of less than 40 cm.