Non-destructive Detection of Grouting Defects Behind Shield Tunnel Wall by Combining Ground Penetrating Radar with Seismic Wave Method

Abstract The shield construction is a mature tunnel technology. Grouting behind segment wall synchronously during an important measure to control stratum deformation, reduce ground settlement and prevent water seepage. quality of grouting can significantly affect the construction. method judgment in early inefficient uncertain. To ensure safety structure, it urgent technical innovation study non-destructive testing technology for effect wall. Nowadays, general Non-destructive methods include penetrating radar detection seismic wave detection. These two meet most needs defect wall, but also have their own advantages disadvantages. Therefore, this proposes combination after defects method, first, used scanning probe grouting, then according further verify results some suspected injury, while efficiency improve recognition accuracy. Finally, verification proposed was carried out based on model test platform, successfully applied actual project metro line Foshan.