Research purposes: The Shizhiyang tunnel of Guangzhou—Shenzhen—Hong Kong High—speed Railway underpasses through the main channel of the Pearl River.When TBM tunnelled in the uneven stratum near the Pead River dam in the direction of the tunnel portal,the ground collapse occurred in large scale,endangering the safety of the Pearl River dam.At the sanle time.TBM could not moved.To resolve this problem,the research Was done on choosing the optimal construction scheme and using above 50 m deep long sleeve—valve—pipe to reinforce the stratum.The feasible methods and measures were offered for guaranteeing the construction conducted smoothly.
Research conclusions: The stratum reinforcement scheme and the sleeve—valve—pine technology presented in this research could solve the problem that the core of the deep sleeve--valve—pipe was stuck or fallen when grouting and the problem that the TBM Was probably packaged when grouting in front of TBM.With improving the stratum by grouting,TBM could work normally.