Abstract:

When aircushiontype slurry shield machines are used in sandy cobble strata, problems, such as cobble accumulation at the bottoms of slurry chambers and air cushion chambers, frequent damage of stone crushers and blocking of slurry circuits, often occur. In this paper, the main causes for the mentioned problems are analyzed. The analysis shows that the main cause for these problems is that the flowing of the slurry in the slurry chambers and air cushion chambers is too slow. Countermeasures, such as adding flushing system for the bottoms of the slurry chambers and air cushion chambers and for the cutter heads, improving the slurry cycling of the main shield bodies and optimizing the structures of the stone crushers, are proposed. 

Key words: Chengdu Metro, sandy cobble strata, slurry cycling, stone crusher, slurry chamber, air cushion chamber, slurry shield