Abstract:

The sudden confined water inrush emergency of ⑦1-2 sandy silt layer pressure water that penetrates through the ⑥ silty clay layer and gushes out of the tunnel portal is studied to find out the leakage treatment measures and protect the safety of surrounding complex environment. Based on the analysis of the causes of the leakage and the comparison of various treatment schemes, the scheme of freezing on the inner wall of the shield shell and sealing the leakage path without shield driving is proposed. When the water leakage channel is blocked, the water in shield receiving shaft is drained, the shield is retained in the soil layer and castinplace reinforced concrete tunnel lining is constructed, and finally the shield is received. The study results show that the polyurethane injection is not effective in blocking the water inrush of the leakage of confined water layer at the tunnel portal, while the leakage channel could be effectively frozen by the cold plate freezing, but the cooling loss caused by the water flow should be considered.

Key words: shield receiving, confined water leakage, emergency control, shield retention, cold plate freezing