EXCAVATION AUXILIARY FOR MUD SHIELD METHOD

摘要

PROBLEM TO BE SOLVED: To realize an excavation auxiliary for mud shield method which ensures a water-stopping property and a lubricating property, realizes smooth excavation and allows smooth pumping of the excavated soil discharged at the excavation step through an earth-removal pipe without adding other chemicals. SOLUTION: This excavation auxiliary for mud shield method contains a carboxyl group-containing polymer which is prepared by copolymerizing anα,β-unsaturated carboxylic acid and an ethylenically unsaturated group- containing compound having at least two ethylenically unsaturated groups. The excavation auxiliary is usually used as an aqueous solution and in a neutralized state achieved through mixing with a basic aqueous solution.