Adding mud material null for shield tunneling method

摘要

PURPOSE: To keep a sealing effect by applying for a high water permeable stratum like a sand layer, by adding a mud slurry composed of specified-formed spherical particles or crushed polymer to a water solvent in order to increase the viscosity. ;CONSTITUTION: Spherical or crushed polymer of 100 pts.wt. like water-absorptive and bridge-formed polyacrylic acid is mixed with a reversed-phase emulsion type water soluble agent of 100-500 pts.wt. such as a polymer like polyvinyl alcohol for instance for increasing the viscosity to produce a mud slurry used for a shielding process. This mud of 0.5-1.5 pts.wt. is added into a fresh water solvent of 100 pts.wt. for instance to make a viscous mud slurry which is poured into the working face. A good cutting-off effect of water can be obtained even in a high water permeable stratum. Or it can keep a sealing effect in a high water permeable stratum like a sand layer or a conglomerate layer.;COPYRIGHT: (C)1994,JPO&Japio