| 摘要 |
PROBLEM TO BE SOLVED: To provide an additive for slurry shield construction method which, even when a drilling fluid contg. a small amount of the additive is mixed into an excavated soil, is capable of discharging and transporting the soil as a flowable slurry without using a large amt. of fine soil particles and to provide a shield construction method wherein an excavated soil can be easily discharged and transported as a slurry by using the additive. SOLUTION: This additive A mainly comprises an aq. soln. of a water-sol. anionic (co)polymer obtd. by the reversed-phase emulsion polymn. of a water-sol. vinyl monomer component contg. 30-100mol% monomer having a sulfone group. The additive A is used by adding it to a drilling soln. for tunnel surplus soil in a shield construction method. |
