PURPOSE:To solidify ground to have high strength, excellent water stopping property and excellent durability comparable to that of cement, by pouring a first soln. obtained by ionizing silicic acid for activation and a specified second soln. into ground separately for confluence in the ground. CONSTITUTION:First soln. (A) which is an aqueous soln. of a compd. of formula, M2O.nSiO2 (where M is a univalent alkali metal) having a viscosity of 5-50cps and second soln. (B) which is an aqueous soln. of a metal (M') compd. (e.g. CaCl2) are poured into ground through separate pouring pipes for confluence and solidification in the ground. The compd. M2O.nSiO2 is obtained by adding a univalent alkali metal hydroxide to silicic acid for ionization and activation and has an SiO2/M2O molar ratio of 1.5-2.5 and a non-colloidal silica content of 60% or higher. The metal (M') compd. forms crystals of formula, xM'2O.ySiO2. 2H2O through interaction with alkali metal.
