Abstract: The accidental drilling of underwater shield tunnel will produce a large amount of gushing water and mud, which will significantly affect the construction and operation of the tunnel, and the repair measures will affect the longterm operation safety of the tunnel. When accidental drilling damage occurs to the underwater tunnel, effective temporary blocking and sealing should be carried, and the one hundredyear operation of tunnel after repairing should be guaranteed. As a result, the repairing idea is put forward. Firstly, the floating ship is used to carry out cement sealing, and the isolation island is built to cut off the connection between the tunnel and the sea water. And then the deformation monitoring on segment and recheck of tunnel central line are carried out after temporary sealing, and the influence of the drilling hole on the tunnel boundary is clarified. The structural safety is evaluated by calculation, and the evaluation results show that the drilling hole has little influence on the segment structure. Finally, the scheme of ground grouting, inhole grouting, inverted cone sealing and inhole bracing steel plate is adopted to repair the tunnel drilling position and ensure the safe operation of the tunnel. In addition, the tunnel protection should be paid attention to when carrying out relevant treatments.

Key words: underwater shield tunnel, segment damage, water gushing and mud bursting, deformation monitoring, center line recheck; structural safety evaluation, segment repair, inverted cone sealing